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Reference Series in PhytochemistrySeries Editors: J.- M. Mérillon · K. G. Ramawat

Bioprocessing of Plant In Vitro Systems

Atanas Pavlov · Thomas Bley Editors

Reference Series in Phytochemistry

Series EditorsJean-Michel MérillonFaculty of Pharmaceutical SciencesUniversity of BordeauxBordeaux, France

Kishan Gopal RamawatBotany DepartmentM.L. Sukhadia UniversityUdaipur, India

This reference works series provides a platform for all information on plant metab-olites and phytochemicals, their chemistry, properties, applications, and methods. Bythe strictest definition, phytochemicals are chemicals derived from plants. However,the term is often used to describe the large number of secondary metabolic com-pounds found in and derived from plants. These metabolites exhibit a number ofnutritional and protective functions for human welfare such as colorants, fragrancesand flavorings, amino acids, pharmaceuticals, hormones, vitamins and agrochemi-cals. Besides food, fibers, fuel, cloth and shelter, a vast number of wild plants canhence provide important sources for medicines, especially in developing countriesfor their traditional health systems. Natural products have inspired and provided thefoundation to the bulk of FDA-approved compounds and there is tremendousincrease in natural products and natural products derived compounds that havebeen registered against many prevailing diseases. Natural product industry hasshown tremendous growth and is expected to continue to do so in the near future.The present series compiles reference information on various topics and aspectsabout phytochemicals, including their potential as natural medicine, their role aschemo-preventers, in plant defense, their ecological role, their role in plants as wellas for pathogen adaptation, and disease resistance. Volumes in the series also containinformation on methods such as metabolomics, genetic engineering of pathways,molecular farming, and obtaining metabolites from lower organisms and marineorganisms besides higher plants. The books in the series are hence of relevance invarious fields, from chemistry, biology, biotechnology, to pharmacognosy, pharma-cology, botany, or medicine. Each volume is edited by leading experts and containsauthoritative contributions by renowned authors.

More information about this series at http://www.springer.com/series/13872

http://www.springer.com/series/13872

Atanas Pavlov • Thomas BleyEditors

Bioprocessing of PlantIn Vitro Systems

With 91 Figures and 29 Tables

EditorsAtanas PavlovUniversity of Food TechnologiesPlovdiv, Bulgaria

The Stephan AngeloffInstitute of MicrobiologyBulgarian Academy of SciencesSofia, Bulgaria

Thomas BleyBioprocess EngineeringInstitute of Food Technology and BioprocessEngineering, TU DresdenDresden, Germany

ISBN 978-3-319-54599-8 ISBN 978-3-319-54600-1 (eBook)ISBN 978-3-319-54601-8 (print and electronic bundle)https://doi.org/10.1007/978-3-319-54600-1

Library of Congress Control Number: 2018934705

# Springer International Publishing AG, part of Springer Nature 2018This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of thematerial is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation,broadcasting, reproduction on microfilms or in any other physical way, and transmission or informationstorage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodologynow known or hereafter developed.The use of general descriptive names, registered names, trademarks, service marks, etc. in this publicationdoes not imply, even in the absence of a specific statement, that such names are exempt from the relevantprotective laws and regulations and therefore free for general use.The publisher, the authors and the editors are safe to assume that the advice and information in this bookare believed to be true and accurate at the date of publication. Neither the publisher nor the authors or theeditors give a warranty, express or implied, with respect to the material contained herein or for any errorsor omissions that may have been made. The publisher remains neutral with regard to jurisdictional claimsin published maps and institutional affiliations.

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https://doi.org/10.1007/978-3-319-54600-1

Preface

Nowadays, because of their valuable pharmaceutical and nutraceutical properties,many plant species have been widely used as ingredients in food, pharmacy, andcosmetic industries. Most of the consumers preferred to use natural products of plantorigin, following closely the growing interest to the concept of modern healthylifestyle, based on prevention by consuming quality foods and natural nutraceuticalsupplements. Therefore, the market for natural plant products has expanded, and thistrend will continue. However, the supply of plant bioactive substances is limited byclimatic, environmental, and ecological reasons, which will lead to shortages ofvarious plant products. These problems could be solved by using plant in vitrotechnologies for producing plant secondary metabolites. There are several importantadvantages of plant in vitro technologies, mainly the independence from climaticconditions and the sustainable production process under controlled conditions. Forthe successful industrial implementation of plant in vitro technology for bioactivesubstances production an integrated approach for process optimization (includingselection of productive lines, media optimization, development of suitable elicitationprocedures, etc.) must be applied. However, the scale-up of cultivation process inbioreactors still appears among the main problems during development and com-mercialization of these technologies. This problem remains unsolved, despite theresearchers’ efforts for more than 55 years in this area.

The aim of this book is to meet the needs of broad range of students, researchers,and specialists working on plant in vitro technologies, and to focus their attention onthe current status, advancement, and the prospects for further developments in thatfield. The book collects chapters written by distinguished scientists and recognizedexperts in their research fields. It covers several sections, guiding the readers fromthe historical background of plant biotechnologies (▶Chaps. 1 and ▶ 2), throughphytochemistry of secondary metabolism with focus on the GC-MS based meta-bolomics (▶Chap. 3) and microbial transformations of plant secondary metabolites(▶Chap. 4). Since plant in vitro technologies are considered as the most prospectiveway for plant secondary metabolites production, all aspects of process developmentand approaches for yields’ improvement (▶Chaps. 5 to ▶ 14) are discussed indetails. Deep reviews are made on bioreactor technologies and process monitoring(▶Chaps. 15, ▶ 16, and ▶ 17). In this book section, critical overviews are made onthe current status of bioreactor cultivations of plant in vitro systems with different

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https://doi.org/10.1007/978-3-319-54600-1_1

degree of differentiation, and possible decisions to overcome limitations for indus-trial implementation of plant in vitro technologies were discussed. In the last section(▶Chaps. 18 and ▶ 19), an overview and examples of the current state of plant-based production systems for expression of different recombinant proteins(▶Chap. 18) as well as summary for application of hairy roots in phytoremediation(▶Chap. 19) are presented.

Finally, we would like to acknowledge all contributing authors for their profes-sionalism and immense efforts in realization of this book. We hope the bookBioprocessing of Plant In Vitro Systems will be a base for further development inresearch and industrial implementation of plant cells and tissue culture technologies.

Atanas PavlovThomas Bley

vi Preface

https://doi.org/10.1007/978-3-319-54600-1_19https://doi.org/10.1007/978-3-319-54600-1_19

Contents

Part I Historical Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1 History of Plant Biotechnology Development . . . . . . . . . . . . . . . . . 3Ivelin Pantchev, Goritsa Rakleova, Atanas Pavlov, andAtanas Atanassov

2 Plant Tissue Culture Technology: Present and FutureDevelopment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39Svetla Yancheva and Violeta Kondakova

Part II Metabolic Phytochemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

3 Metabolite Profiling of In Vitro Plant Systems . . . . . . . . . . . . . . . . 67Strahil Berkov, Liliya Georgieva, Borjana Sidjimova, andMilena Nikolova

4 Microbial Transformations of Plant Secondary Metabolites . . . . . 85Blaga Mutafova, Pedro Fernandes, Sava Mutafov, Strahil Berkov, andAtanas Pavlov

Part III Secondary Metabolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

5 Engineering Cell and Organ Cultures from Medicinal andAromatic Plants Toward Commercial Production ofBioactive Metabolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127Krasimir Rusanov, Atanas Atanassov, and Ivan Atanassov

6 Agrobacterium rhizogenes-Mediated Transformation of Plantsfor Improvement of Yields of Secondary Metabolites . . . . . . . . . . 161Tatiana V. Matveeva and Sophie V. Sokornova

7 Amaryllidaceae Alkaloid Accumulation by Plant In VitroSystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203Dominique Laurain-Mattar and Agata Ptak

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8 Sustainable Production of Polyphenols and Antioxidants by PlantIn Vitro Cultures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225Iryna Smetanska

9 Production of Iridoid and Phenylethanoid Glycosides by In VitroSystems of Plants from the Buddlejaceae, Orobanchaceae, andScrophulariaceae Families . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271Ewelina Piątczak, Renata Grąbkowska, and Halina Wysokińska

10 Taxus Cell Cultures, an Effective Biotechnological Tool toEnhance and Gain New Biosynthetic Insights into TaxaneProduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295Heriberto Vidal-Limon, Raúl Sanchez-Muñoz, Abbas Khojasteh,Elisabeth Moyano, Rosa M. Cusido, and Javier Palazon

11 Challenges for the Cultivation of Plant Cells on the Example ofHypericum perforatum and Taxus chinensis . . . . . . . . . . . . . . . . . . 317Mariam Gaid, Thomas Wucherpfennig, Stephan Scholl,Ludger Beerhues, and Rainer Krull

12 Mass Production of Artemisinin Using Hairy Root Cultivationof Artemisia annua in Bioreactor . . . . . . . . . . . . . . . . . . . . . . . . . . 343Nivedita Patra and Ashok K. Srivastava

13 Plant In Vitro Systems as Sources of Food Ingredients andAdditives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361Radka Vrancheva, Nadezhda Petkova, and Ivan Ivanov

14 Safety Assessment and Regulations for Food Ingredients Derivedfrom Plant In Vitro systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393Angel Angelov and Velitchka Gotcheva

Part IV Bioreactor Technology and Monitoring . . . . . . . . . . . . . . . 411

15 Bioreactor Technology for Sustainable Production of PlantCell-Derived Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413Sören Werner, Rüdiger W. Maschke, Dieter Eibl, and Regine Eibl

16 Monitoring of Plant Cells and Tissues in Bioprocesses . . . . . . . . . 433Juliane Steingroewer, Christiane Haas, Katja Winkler, Carolin Schott,Jost Weber, Julia Seidel, Felix Krujatz, Sibylle Kümmritz, Anja Lode,Maria Lisa Socher, Michael Gelinsky, and Thomas Bley

17 Bioreactor Technology for Hairy Roots Cultivation . . . . . . . . . . . . 483Shakti Mehrotra, Sonal Mishra, and Vikas Srivastava

viii Contents

Part V Other Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 507

18 Platforms for Plant-Based Protein Production . . . . . . . . . . . . . . . . 509Jianfeng Xu, Melissa Towler, and Pamela J. Weathers

19 Hairy Roots and Phytoremediation . . . . . . . . . . . . . . . . . . . . . . . . 549Anrini Majumder, Smita Ray, and Sumita Jha

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 573

Contents ix

About the Editors

Atanas Pavlov is a Professor at the University of FoodTechnologies, Plovdiv, Bulgaria, and at the StephanAngeloff Institute of Microbiology, Bulgarian Academyof Sciences. He graduated his Master’s degree in Bio-technology in 1992 at the University of Food Technol-ogies, Plovdiv, Bulgaria. Later, in 1998, he completedhis Ph.D. in Biotechnology at the Stephan AngeloffInstitute of Microbiology, Bulgarian Academy of Sci-ences, and held position as an Assistant Professor at thesame institute. From 2003 to 2005, he did postdoctoralresearch at the Institute of Food Technologies andBioprocess Engineering, Technische Universität Dres-den, Germany, working on bioprocess engineering ofproduct synthesis with plant in vitro cultures. In 2005,he joined, as an Associate Professor, the scientific group“Bioactive substances from plant in vitro systems”which is a part of Department of Microbial Biosynthesisand Biotechnologies, The Stephan Angeloff Institute ofMicrobiology, Bulgarian Academy of Sciences. In2009, he received his habilitation (DSci). From 2015,Atanas Pavlov is a corresponding member of BulgarianAcademy of Sciences. His research is mainly focused onthe production of specific bioactive metabolites by plantcell, tissue, and organ cultures.

xi

Thomas Bley studied mathematics at the Dresden Uni-versity of Technology (Germany). From 1975 until1990, he worked as a scientist at the Institute of Bio-technology (IBT) at the Academy of Science of theGDR in Leipzig. He received his doctorate in 1981and his habilitation in 1990 with theses in the field ofmodeling microbial population dynamics. In the follow-ing years, he was the Head of the Division of Biotech-nology at the University of Leipzig. Since 1996, he hasheld the Chair of bioprocess engineering and is Head ofthis study course at the Technische Universität Dresden.Prof. Bley is a full member of the German Academy ofScience and Engineering (acatech) and of the SaxonAcademy of Sciences. He is an active member of numer-ous organizations and technical committees in the fieldof Bioprocess Engineering. Prof. Bley’s main fields ofresearch are white biotechnology, biomonitoring andbiosignals, dynamics of microbial populations, model-ing and control of bioprocesses, flow cytometry, andplant cell cultivation (# Photo Hüller).

xii About the Editors

Contributors

Angel Angelov Department of Biotechnology, Center for Food Quality and SafetyEducation, University of Food Technologies, Plovdiv, Bulgaria

Atanas Atanassov Joint Genomic Center Ltd., Sofia, Bulgaria

Ivan Atanassov AgroBioInstitute, Sofia, Bulgaria

Ludger Beerhues Institute of Pharmaceutical Biology, Technische UniversitätBraunschweig, Braunschweig, Germany

Center of Pharmaceutical Engineering, Technische Universität Braunschweig,Braunschweig, Germany

Strahil Berkov Institute of Biodiversity and Ecosystem Research at the BulgarianAcademy of Sciences, Sofia, Bulgaria

Thomas Bley Bioprocess Engineering, Institute of Food Technology andBioprocess Engineering, TU Dresden, Dresden, Germany

Rosa M. Cusido Laboratori de Fisiología Vegetal, Facultat de Farmacia,Universitat de Barcelona, Barcelona, Spain

Dieter Eibl LSFM School of Life Sciences and Facility Management, ICBT Insti-tute of Chemistry and Biotechnology, ZHAW Zurich University of Applied Sci-ences, Wädenswil, Switzerland

Regine Eibl LSFM School of Life Sciences and Facility Management, ICBTInstitute of Chemistry and Biotechnology, ZHAW Zurich University of AppliedSciences, Wädenswil, Switzerland

Pedro Fernandes iBB – Institute for Bioengineering and Biosciences, Departmentof Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon,Portugal

Mariam Gaid Institute of Pharmaceutical Biology, Technische Universität Braun-schweig, Braunschweig, Germany


xiii

Michael Gelinsky Centre for Translational Bone, Joint and Soft Tissue Research,Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden,Germany

Liliya Georgieva Agrobioinstitute, Sofia, Bulgaria

Velitchka Gotcheva Department of Biotechnology, Center for Food Quality andSafety Education, University of Food Technologies, Plovdiv, Bulgaria

Renata Grąbkowska Department of Biology and Pharmaceutical Botany, MedicalUniversity, Łódź, Poland

Christiane Haas Institute of Natural Materials Technology, Technische UniversitätDresden, Dresden, Germany

Ivan Ivanov Department of Organic Chemistry, University of Food Technologies,Plovdiv, Bulgaria

Sumita Jha Centre of Advanced Study, Department of Botany, University ofCalcutta, Kolkata, India

Abbas Khojasteh Laboratori de Fisiología Vegetal, Facultat de Farmacia,Universitat de Barcelona, Barcelona, Spain

Felix Krujatz Institute of Natural Materials Technology, Technische UniversitätDresden, Dresden, Germany

Rainer Krull Institute of Pharmaceutical Biology, Technische Universität Braun-schweig, Braunschweig, Germany


Violeta Kondakova AgroBioInstitute, Sofia, Bulgaria

Sibylle Kümmritz Institute of Natural Materials Technology, TechnischeUniversität Dresden, Dresden, Germany

Dominique Laurain-Mattar Université de Lorraine, SRSMC, UMR 7565, CNRS,BP 70239, Vandœuvre-lès-Nancy, FranceCNRS, SRSMC, UMR 7565, BP 70239, Vandœuvre-lès-Nancy, France

Anja Lode Centre for Translational Bone, Joint and Soft Tissue Research, Facultyof Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany

Anrini Majumder Centre of Advanced Study, Department of Botany, Universityof Calcutta, Kolkata, India

Rüdiger W. Maschke LSFM School of Life Sciences and Facility Management,ICBT Institute of Chemistry and Biotechnology, ZHAW Zurich University ofApplied Sciences, Wädenswil, Switzerland

Tatiana V. Matveeva St. Petersburg State University, St. Petersburg, Russia

xiv Contributors

Shakti Mehrotra Plant Biotechnology Division, Central Institute of Medicinal andAromatic Plants, Lucknow, India

Sonal Mishra National Institute of Plant Genome Research, New Delhi, India

Elisabeth Moyano Departament de Ciencies Experimentals i de la Salut,Universitat Pompeu Fabra, Barcelona, Spain

Sava Mutafov The Stephan Angeloff Institute of Microbiology, Bulgarian Acad-emy of Sciences, Sofia, Bulgaria

Blaga Mutafova The Stephan Angeloff Institute of Microbiology, Bulgarian Acad-emy of Sciences, Sofia, Bulgaria

Milena Nikolova Institute of Biodiversity and Ecosystem Research at the Bulgar-ian Academy of Sciences, Sofia, Bulgaria

Javier Palazon Laboratori de Fisiología Vegetal, Facultat de Farmacia, Universitatde Barcelona, Barcelona, Spain

Ivelin Pantchev Joint Genomic Center Ltd., Sofia, Bulgaria

Department of Biochemistry, Faculty of Biology, Sofia University, Sofia, Bulgaria

Nivedita Patra Department of Biotechnology and Medical Engineering, NationalInstitute of Technology Rourkela, Rourkela, Odisha, India

Atanas Pavlov University of Food Technologies, Plovdiv, Bulgaria

The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences,Sofia, Bulgaria

Nadezhda Petkova Department of Organic Chemistry, University of Food Tech-nologies, Plovdiv, Bulgaria

Ewelina Piątczak Department of Biology and Pharmaceutical Botany, MedicalUniversity, Łódź, Poland

Agata Ptak Department of Plant Breeding and Seed Science, University of Agri-culture in Krakow, Krakow, Poland

Goritsa Rakleova Joint Genomic Center Ltd., Sofia, Bulgaria

Smita Ray Bethune College, Kolkata, India

Krasimir Rusanov AgroBioInstitute, Sofia, Bulgaria

Raúl Sanchez-Muñoz Departament de Ciencies Experimentals i de la Salut,Universitat Pompeu Fabra, Barcelona, Spain

Stephan Scholl Institute of Pharmaceutical Biology, Technische Universität Braun-schweig, Braunschweig, Germany


Contributors xv

Carolin Schott Institute of Natural Materials Technology, Technische UniversitätDresden, Dresden, Germany

Julia Seidel Institute of Natural Materials Technology, Technische UniversitätDresden, Dresden, Germany

Centre for Translational Bone, Joint and Soft Tissue Research, Faculty of MedicineCarl Gustav Carus, Technische Universität Dresden, Dresden, Germany

Borjana Sidjimova Institute of Biodiversity and Ecosystem Research at the Bul-garian Academy of Sciences, Sofia, Bulgaria

Iryna Smetanska Plant Production and Processing, Agricultural Faculty, Triesdorf,University of Applied Sciences Weihenstephan-Triesdorf, Weidenbach, Germany

Maria Lisa Socher Institute of Natural Materials Technology, TechnischeUniversität Dresden, Dresden, Germany

Sophie V. Sokornova St. Petersburg State University, St. Petersburg, Russia

All Russian Institute of Plant Protection, St. Petersburg, Russia

Ashok K. Srivastava Department of Biochemical Engineering and Biotechnology,Indian Institute of Technology Delhi, New Delhi, India

Vikas Srivastava Department of Plant Sciences, Central University of Jammu,Jammu (J & K), India

Juliane Steingroewer Institute of Natural Materials Technology, TechnischeUniversität Dresden, Dresden, Germany

Melissa Towler Biology and Biotechnology Department, Worcester PolytechnicInstitute, Worcester, MA, USA

Heriberto Vidal-Limon Laboratori de Fisiología Vegetal, Facultat de Farmacia,Universitat de Barcelona, Barcelona, Spain

Radka Vrancheva Department of Analytical Chemistry, University of Food Tech-nologies, Plovdiv, Bulgaria

Pamela J. Weathers Biology and Biotechnology Department, Worcester Polytech-nic Institute, Worcester, MA, USA

Jost Weber Institute of Natural Materials Technology, Technische UniversitätDresden, Dresden, Germany

Evolva Copenhagen, Copenhagen, Denmark

Sören Werner LSFM School of Life Sciences and Facility Management, ICBTInstitute of Chemistry and Biotechnology, ZHAW Zurich University of AppliedSciences, Wädenswil, Switzerland

Katja Winkler Institute of Natural Materials Technology, Technische UniversitätDresden, Dresden, Germany

xvi Contributors

Thomas Wucherpfennig Institute of Biochemical Engineering, TechnischeUniversität Braunschweig, Braunschweig, Germany

Halina Wysokińska Department of Biology and Pharmaceutical Botany, MedicalUniversity, Łódź, Poland

Jianfeng Xu Arkansas Biosciences Institute, Arkansas State University, Jonesboro,AR, USA

Svetla Yancheva Agricultural University, Plovdiv, Bulgaria

Contributors xvii

Part I

Historical Background

History of Plant BiotechnologyDevelopment 1Ivelin Pantchev, Goritsa Rakleova, Atanas Pavlov, andAtanas Atanassov

Contents1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Brief History Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.1 Prescience Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.2 Cell Theory and Early Works in the Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.3 The Birth of the Modern Plant Biotechnology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82.4 Turn of the Century . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92.5 New Millennium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112.6 Plant Biotechnology Around the World . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

3 Plant Biotechnology Interplays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143.1 Fundamental Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143.2 Agriculture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163.3 Transgenic Technologies and GMO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183.4 Plant Biotechnology for In Vitro Production in Bioreactors . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4 Future Developments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234.1 Integration with the Omics and Marker Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234.2 Integration with Gene and Genome Manipulation Approaches . . . . . . . . . . . . . . . . . . . . . . . 26

I. PantchevJoint Genomic Center Ltd., Sofia, Bulgaria

Department of Biochemistry, Faculty of Biology, Sofia University, Sofia, Bulgariae-mail: [email protected]

G. Rakleova · A. Atanassov (*)Joint Genomic Center Ltd., Sofia, Bulgariae-mail: [email protected]; [email protected]

A. PavlovUniversity of Food Technologies, Plovdiv, Bulgaria

The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgariae-mail: [email protected]

# Springer International Publishing AG, part of Springer Nature 2018A. Pavlov, T. Bley (eds.), Bioprocessing of Plant In Vitro Systems, Reference Series inPhytochemistry, https://doi.org/10.1007/978-3-319-54600-1_25

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4.3 Tool for Integrated Crop Breeding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274.4 Intellectual Property Rights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

AbstractIt is difficult to write a review on the history of plant biotechnology, especiallyafter the excellent works of Vasil (Plant Cell Rep 27(9):1423–1440, 2008)Thorpe (Mol Biotechnol 37:169–180, 2007), and Sussex (Plant Cell 20(5):1189–1198, 2008). It is even more difficult to overview the current state ofthis fast-developing field. Nevertheless, in this review we will make an attemptnot only to make a narrative of main stages but also to show the links betweenplant biotechnology and latest progress in biological science.

Plant biotechnology has its roots deep in human civilization but wasestablished just a century ago. Starting outside the science mainstream of thetime period, classical plant biotechnology slowly but steadily grew into arecognized discipline. The explosive growth of biology research at the end ofthe twentieth century brought plant biotechnology to the fast-track line. Thefield grew very rapidly and currently turned into a key tool for fundamentalresearch and practical uses. Currently plant biotechnology has been essentiallygrown, and new disciplines as omics technologies as genome editinghave arisen which further intensify both fundamental and practical studies inbiology and make a bridge with other scientific areas as informatics, nanotech-nology, and so-called digital and intelligent science. As such modern biotech-nology speeds up the development of the Fourth Industrial Revolution(Schwab, The fourth industrial revolution. World Economic Forum. ISBN1944835008, 2016).

KeywordsPlant tissue culture · Transgenic technologies · Omics · Gene editing ·Epigenetics · Marker-assisted breeding · Protoplast · Plant transformation · Cellfactories · Bioreactors

Abbreviations2-DE Two-dimensional electrophoresisBt-toxin Toxic protein from Bacillus thuringiensisCGIAR Consultative Group for International Agricultural ResearchCRISPR/Cas Clustered Regularly Interspaced Short Palindromic Repeats/

CRISPR-associated proteinCYMMIT Centro Internacional de Mejoramiento de Maíz y Trigo (Interna-

tional Maize and Wheat Improvement Centre)GC-MS Gas chromatography-mass spectrometry

4 I. Pantchev et al.

GM Genetic modificationGMO Genetically modified organismGWAS Genome-wide association studiesICGEB International Centre for Genetic Engineering and BiotechnologyICRISAT International Crops Research Institute for the Semi-Arid TropicsIPR Intellectual property rightsIRRI International Rice Research InstituteLC-MS Liquid chromatography-mass spectrometryNIRS Near-infrared spectroscopyNMR Nuclear magnetic resonanceRNAi RNA interferenceSNP Single-nucleotide polymorphismT-DNA Transferred DNA from Ti-plasmid (or binary vector) into plant

cellTi-plasmid Tumor-inducing plasmid of Agrobacterium tumefaciens

1 Introduction

It is difficult to write a review on the history of plant biotechnology, especially afterthe excellent works of Thorpe [1], Vasil [2], and Sussex [3]. It is even more difficultto overview the current state of this fast-developing field. Nevertheless, in thisreview we will make an attempt not only to make a narrative of the main stagesbut also to show the links between plant biotechnology and latest progress inbiological science.

Nowadays plant biotechnology turned into a valuable tool for modern biology aspredicted by Altman et al. [4]. In vitro cultures served as model systems for studyingfundamental processes in cells and whole plants. Transgenic technologies allowedfor detailed characterization of gene functions and interplays. Plant tissue cultureswere also extensively used for production of complex chemical compounds, either asnative metabolites or through enzyme processing of precursors [5–8].

Integration of classic plant biotechnology methods with latest molecular biologyapproaches (especially DNA marker techniques) allowed the establishment of effi-cient molecular breeding programs [9].

Currently plant biotechnology has been essentially grown, and new disciplines asomics technologies as genome editing have arisen which further intensify bothfundamental and practical studies in biology and make a bridge with other scientificareas as informatics, nanotechnology, and so-called digital and intelligent science.As such, modern biotechnology speeds up the development of the Fourth IndustrialRevolution [10].

Revealing the links between early experiments and observations and currentdevelopments in the field is tough and challenging task. It is easy to miss somerelations or key publications. We are well aware of our weaknesses but are open toany further critics.

1 History of Plant Biotechnology Development 5

2 Brief History Overview

Plant biotechnology from a historic perspective is a challenging but interesting field tooverview from the very beginning of plant tissue culture [11].With roots deep in humancivilization, it steadily grew into a contemporary discipline and successfully turned intoan integral part of modern plant science with strong impact of all related humanactivities [12, 13]. The most fascinating feature is that in its present state, plantbiotechnology exploits or supplements numerous approaches from chemistry andbiology. It also became an indispensable tool for establishment of modern bioeconomy[14–16]. The most notable example is the Netherlands. Successful implementation ofstate-of-the-art methods with classic techniques boosted the agroeconomy of this smallcountry, bringing it to a second position as agro-food exporter in the world. One of thebiotech companies in this country –KeyGene – is an excellent example for integrationof latest scientific achievements into breeding programs [17] (http://www.keygene.com/news/). The most important consequence is that this integrated approach isgradually adopted throughout the world and steadily turns into a “golden standard”for modern plant biotech companies and national biotech programs.

Between the early empirical observations and the implementation as a keystonefor national success is a story of rise and development of plant biotechnology as ascientific discipline (Fig. 1).

2.1 Prescience Times

Growing plants was one of the prerequisites for establishing the modern civilization.It is anticipated that the earliest agriculture took place some 12,000–14,000 yearsago allowing for first complex societies to emerge.

Initially plant growing was simple enough, but soon primitive crop breedingallowed higher yield. Surprisingly, “plant biotechnology” practices also arise in theforms of grafting and vegetative propagation. This was based on observations andpractical experience and, obviously, lacks any scientific grounds. Like the use offermentations processes, these practices receive scientific explanation and deeperexplorations only after establishing the modern cell theory and expanded growth ofmodern bioscience.

2.2 Cell Theory and Early Works in the Field

The principles of modern science were formed during the Renaissance. The inven-tion of the microscope revealed the intrinsic organization of the living matterincluding plants. Among the morphologic descriptions was the observation ofunorganized tissue growth (in fact, callus) at wounds on plants. However, the lackof sufficient scientific knowledge prevented further experimental studies ex planta.

The origins of modern plant biotechnology can be traced back to the works ofSchleiden [18] and Schwann [19], who postulated that the cell is both the least living


http://www.keygene.com/newshttp://www.keygene.com/news

Fig. 1 Milestones in plant biotechnology development – a timeline


structure and the key building part of all complex organisms on Earth. The celltheory thus played central role in the establishment of modern biology in its vastdiverse. The key impact for the future of plant biotechnology was the concept of celltotipotency, which actually opened the door of all future developments in the field.However, its validation relatively to the plant cells was achieved only in 1965 [20].

Plant biotechnology would not be possible without the reproductive technologiesof plant tissue culture and cloning. During the nineteenth century, the trends in plantsciences were still directed toward the understanding of the basics like plant anatomyand physiology. First attempts to manipulate plants in a “biotechnology manner”have place at the turn of the century, when sufficient knowledge was accumulated.The pioneering works of Vöchting [21], Rechinger [22], and especially Haberlandt[23] had demonstrated that plant cells could be maintained in vitro. Later, Robbins[24] and Kotte [25] successfully grew plant tissue on artificially designed media.Their success as compared to the pioneering works was due to the substantialknowledge on cell biology that has been accumulated at that time.

In the late 1920s of the twentieth century, the first plant hormone – auxin – wasidentified [26], isolated, and characterized in details [27, 28]. These works explainedthe earlier observations of Charles Darwin and his son Francis in the 1880s on thepossible internal signal factor related to the polarized plant growth [29].

However, it needed another decade and substantial new scientific work in order toprovide reliable in vitro growing conditions with more or less defined parameters ofthe media composition, environmental conditions, and, more important, the role ofthe nutrition factors and hormones [30, 31].

As a result, in the mid-1930s, there were several excellent demonstrations of thepotential of plant tissue culture not only for fundamental research but also forpractical purposes. The key achievements were related to callus formation andorgan regeneration, paving the road to micropropagation, embryo rescue, anddouble-haploid techniques – important tools for modern plant breeding.

Saying it simply – the plant biotechnology in its modern form was found.

2.3 The Birth of the Modern Plant Biotechnology

Modern plant biotechnology has arisen from the achievements of plant physiologyand biochemistry. During the first half of the twentieth century, all key biochemicalpathways were revealed, and substantial knowledge on plant physiology had accu-mulated. This critical mass of scientific information allowed for clear identificationof most appropriate research directions as well as for better experimental designs.

The next two decades (1940–1960) had been a “transition” from proof-of-the-concept stage to a now useful tool for plant research and manipulation. There wereseveral key milestones. First one is the production of haploid cultures from pollen,paving the way for a powerful future tool in plant molecular genetics and plantbreeding [32].

Another important technique was the introduction of suspension cell culture byHildebrandt group in 1954 [33]. The possibility to maintain and manipulate a


culture of single cells outlined the future success in studying cell proliferation anddifferentiation. The technique was a prerequisite to validate plant cell totipotency(de- and differentiation), thus providing scientific background for future planttransgenesis.

Among the most remarkable achievements during this period were the discoveryof key plant hormones and scientific explanation of their role during in vitrocultivation process. The discovery of the role of adenine and its derivative – kinetin– along with the effects of auxin allowed for detailed estimation of the growthparameters [34]. Latest chain of research led to the development of the first “more orless universal” recipe for tissue growing – the famous Murashige and Skoog medium[35]. It is interesting that the discovery of kinetin was related to the interest in thebiochemistry of nucleic acids and especially their degradation. This is a niceexample how the achievements in a particular discipline boost the progress in aseemingly unrelated field.

In 1960 the next key step in plant biotechnology took place. Cocking [36]successfully applied enzyme treatment to produce first viable protoplast culturewhich became an important tool for the time being.

From this period are the first records for practical use of plant biotechnology.Morel [37] had used its modified shoot apex technique for orchid propagation.

In its pioneering work, Guha and Maheshwari [38] had successfully culturedanthers and pollen to produce haploid embryos. Their achievement had laid the pathto the production of homozygous dihaploid plants within 5 months. Another impor-tant tool in modern crop breeding was born.

In 1963 The International Association for Plant Biotechnology was founded. Thisevent symbolizes the transition of the field from juvenile stage to maturity.

During the 1970s plant biotechnology gained significant pace. In vitro cultivationof plant cells and tissue became an important tool for both fundamental research andpractical use. First, protoplast technique has showed remarkable potential, andinterspecific fusions were obtained between cells of different plant species[39]. Also, during this period, first plant transformation of protoplasts with foreignDNAwas demonstrated.

Cell and tissue cultures became indispensable tool for biochemical, genetic, andmolecular research. The in vitro selection was applied in order to produce plantmaterial suitable for agriculture [40]. A new topic – somaclonal variation – had beenstudied [41] but later was abandoned. Further investigations revealed that, in fact,somaclonal variation was a result from stress-induced activation of mobile geneticelements [42].

Modern plant biotechnology was already established, and the fundament for thefuture fast development was build (Fig. 2).

2.4 Turn of the Century

The end of the twentieth century is characterizedwith vast expansion in thefield of plantbiotechnology. Most significant achievement was the establishment of plant


transformation procedures. First works were on protoplasts but soon after two morepractical approaches were introduced. First was the transformation by Agrobacterium,and, almost simultaneously, particle bombardment was also demonstrated. Both tech-niques soon became a standard for the plant biotechnology community, prevailing overthe other alternative methods like electroporation, ultrasonic transformation, siliconcarbide whiskers, microinjection, etc. Thus, plant transformation methods became anintegral part of the modern plant biotechnology and keystone for a whole new researchfield.

The overall development of molecular biology techniques has reflected on plantbiotechnology in number of ways.

In vitro cultivation along with dihaploid plant generation greatly influencedplant molecular genetics by advancing the development of molecular markers[43]. In turn, these techniques resulted in molecular breeding, which effectivelysupplemented and greatly facilitated crop selection. Nowadays, the integration of themarker-assisted selection with plant biotechnology techniques is the only viableapproach to achieve sustainable and competitive crop breeding.

The introduction of in vitro DNA amplification (PCR) and DNA sequencing ledto an expansion of our knowledge on plant genes and genetic elements. Genes werecloned and analyzed in their thousands. Slowly but steadily many empirical obser-vations related to in vitro culture and regeneration received their molecularexplanations.

Fig. 2 Developments in plant biotechnology


2.5 New Millennium

Currently plant biotechnology is recognized as an important tool for both funda-mental research as well as practical purposes.

An important feature is that development takes place not only at universities andresearch institutes but also in numerous private companies. First private entities werefound in the 1980s – Calgene, DNA Plant Technology Corp., Phytogene, PlantGenetics Inc., and International Plant Research Institute, to name a few. During thatperiod several large corporations also turned toward the field like Ciba-Geigy,DEKALB AgResearch, DuPont, Monsanto, Pioneer Hi-Bred, and Sandoz. In fact,most multinational corporations realized that investment in plant biotechnology isone of the prerequisites for market success. Not all of the initial players managed tosurvive for the next three decades when the economic conditions lead to resourceconcentrations and currently to very few major companies with a strong impact on thefield. In the last few years, important mergers occurred among most of them – Bayerwith Monsanto, Syngenta with Chem China, and DuPont with Dow Chemical.

The current state in the field has its origins in the explosive development of novelmethods and techniques in biological sciences.

There were several key prerequisites.First breakthrough was the development of improved chromatographic equip-

ment. The introduction of mass spectrometry along with liquid or gas chromatogra-phy leads to a new level of chemical characterization which is now known asmetabolomics. Several techniques, namely, LC-MS, GC-MS, NMR, and NIRS,allowed detailed analysis of chemical composition in minuscule quantities as wellas metabolite dynamics.

Second breakthrough was related to the better understanding in plant moleculargenetics. The introduction of the PCR made possible the development of high-density genetic maps. However, the major impact had the introduction of massiveparallel sequencing. It revealed the fine organization of the plant genome.Many empirical observations had found its explanation, especially the phenome-non of epigenetics. The discovery of novel regulatory structures and elements inturn led to the development of novel tools for analyzing gene expression and geneinteractions.

Genome sequencing was also a prerequisite for the latest state-of-the-art tech-nique – genome editing. This turns to be a method of enormous importance for thenext decade or two, allowing for directed manipulation of plant genomes withimmense effect on the future of plant sciences.

Third breakthrough was related to the introduction of bioinformatics which leadsto the development of omics technologies. The integral omics approaches allowedfor efficient analysis of plants as well as for better understanding of all processes andtheir relations with the environment.

Fourth breakthrough was related to the spread of reproducible transformationtechnologies. It allowed for detailed characterization of gene interplays and betterunderstanding of plant biology at all levels. Furthermore, it leads to explosive


development of genetically modified plants for numerous practical purposes outsidethe fundamental research.

2.6 Plant Biotechnology Around the World

Another interesting point is how plant biotechnology was developed in differentcountries especially in the developing world [44]. The mainstream works wereperformed in leading scientific centers in Western Europe and the USA. This reflectsthe fact that these countries were leaders in science during the nineteenth and the firsthalf of the twentieth century. During the second half of the twentieth century, theglobal political processes allowed formation and fast development of new scientificcenters. Some of them had direct links with well-renowned Western science schools(Australia, Canada) or were closely related (Japan, China), while others were formedor developed independently (mainly from former Soviet Bloc). Nevertheless, in allcases the foundation was based on contemporary science, and there were stronginterconnections between centers around the world.

Plant biotechnology in Australia and Canada had tight links with the leadinguniversities and research institutes in the UK and USA. The scientists from thesecountries had demonstrated excellent achievements in all aspects of the field rangingfrom cell and tissue cultivation to transformation of different crops and wild species.

During the second half of the twentieth century, Japan proved to be the first andfast-developing research center in plant biotechnology. One of the major contribu-tions was the discovery of the gibberellins [45]. For different reasons plant biotech-nology research was intense after the WWII. Development was enormous, andcurrently there are over 150 research centers implementing plant biotechnologymethods. Japanese scientists prove their expertise in plant biotechnology by devel-oping a broad scope of research objectives.

China has developed its research capabilities relatively late but was able to exploitand integrate all best practices from the world science. During the last 30 years of thetwentieth century, the main focus was on anther cultures and haploid breeding. Atthe turn of the millennium, the interest included the plant transgenic research, andsubstantial efforts were made in this direction [46]. Currently there is an explosion ofresearch centers at universities, institutes, and private entities (over 220 key labs)covering all aspects of modern plant biotechnology. As a result, transgenic plantshave been elaborated in more than 50 economically important crop varieties (cotton,tomato, tobacco, potato, petunia, and some others that have reached the Chinesemarket first at beginning of the 1990s) and are ready for commercialization. Theseefforts are of utmost importance for China, not only for implementation in agricul-ture but for achieving a more global target – sustainable and competitivebioeconomy.

India had gained independency in 1947. It took nearly three decades to establish anet of national research infrastructure capable of extensive implementation of plantbiotechnology approaches for practical purposes. Initial interest was toward the useof haploid cultures and embryo rescue techniques for facilitating plant breeding


programs. Next, there was successful use of protoplast fusion for producing inter-specific and intergeneric hybrids. Nowadays India has developed outstanding capac-ities for plant biotechnology research on broad spectrum of crops and medicinalplants [47], attempting to link ethnomedicine and metabolome [48].

Another interesting example of a country with fast-developing plant biotechresearch and industry is Israel. Since the independence, gained in 1948, Israel hadgradually developed an efficient agriculture sector. Benefitting from a large numberof highly educated scientists, trained at leading research centers around the worldand with strong administrative support, Israel managed to establish a set of top-classinstitutes like Volcani Centre (http://www.agri.gov.il/en/pages/1023.aspx), develop-ing and implementing state-of-the-art plant science approaches. Another distinctivefeature is the rise of a number of plant biotech companies during the last decades,some of them at a leading position in particular field. More important, there is astrong interaction between the fundamental science and industry, which furtherstrengthen the position of plant biotechnology as a tool for sustainable economicgrowth.

A country with strong potential in plant biotechnology is Turkey. The existinggene pools, cultivated areas, and human recourses, combined with nearly 200 uni-versities and research centers and under serious governmental support, have resultedin fast development of plant biotechnology and related services. The key prerequisitewas the establishment of TUBITAK as a peer to the numerous centers and labora-tories. This structure resembles well-known structures in the EU and USA likeINRA, NSF, and BBSRC. As a result, Turkey had succeeded in building top-levelresearch infrastructure and education of skilled researchers. Another line of supportis provided by seed associations and private companies with interest in molecularbreeding and transgenic research. Currently, almost all new techniques could beapplied for plant improvement along with the classical breeding and germplasmconservation [49] (Prof. Dr. Nermin Gozukirmizi, personal communication).

On March 18, 2010, Turkey’s parliament passed a National Biosafety Law, whichregulates the production and import of all products of, containing, or derived frombiotechnology, except for drugs and cosmetics. According to Biosafety Law, it isforbidden to cultivate GM crops and animals in Turkey.

The establishment of plant biotechnology in Russia had its roots in the generaldevelopment of life science at the turn of the twentieth century. Nevertheless, workson plant tissue culture were initiated by Butenko in 1957 at the Institute of PlantPhysiology RAS, Moscow [50], in direct collaboration of with the Gautheret labo-ratory. Under Butenko’s strong guidance and coordination, plant tissue culturemethods have been successfully implemented in most former Soviet Union countries[51]. Along with the USA, the Soviet Union was pioneering studies on the effect ofspace environment on different aspects of plant cell and tissue culture. In the 1970sand 1980s, research on protoplasts and plant transformation was also initiated.During the last decades, plant research was concentrated in several institutes anduniversities, especially those related to the agriculture industry [52].

The development of plant biotechnology in the countries for Central and EastEurope began after WWII and was uneven. Poland, former Czechoslovakia,


http://www.agri.gov.il/en/pages/1023.aspx

Hungary, former Yugoslavia, Romania, and Bulgaria had strong scientific traditionsand were able to establish high-quality research on plant tissue culture in the late1960s. Due to historical reasons, most of the research was directly related toagriculture, while fundamental aspects were studied to a lesser extent. The bestexamples to be mentioned are Biological Research Center, Szeged (Denes Duditsand Pal Maliga), Hungary, [53] and Institute of Genetic Engineering, Kostinbrod,Bulgaria. Since 2000 it has been renamed Agrobioinstitute which in 1999 has beenselected by EC as a first Center of Excellence for Plant Biotechnology among all thescientific disciplines and among all the accession countries to EC. Especially forBulgaria, first works on plant tissue cultures that paved the way to modern plantbiotechnology were by Kikindonov and Atanassov [54–56].

An interesting development was the establishment of UN research facilities(CGIAR) throughout the world, most of them in so-called developing countries.These 16 research institutes had broad scientific scope including plant biotechnol-ogy. Among the most prominent are CYMMIT (Mexico), IRRI (the Philippines),and ICRISAT (India). Similar role has played ICGEB (India, South Africa). In theseinstitutes plant biotechnology was either used as a key tool or was an independentresearch subject. The long-term impact of these centers on the regional developmentproved to be significant. They have successfully served both as a starting platformand a center of excellence for newly build local scientific communities.

3 Plant Biotechnology Interplays

The maturation of plant tissue culture techniques led to their integration in severaldifferent scientific and industrial fields (Fig. 3).

3.1 Fundamental Research

The implementation of plant biotechnology tools in fundamental research started veryearly. Cell and tissue culture was the workhorse of elucidation of plant hormoneaction. Since the introduction of molecular biology and genetic engineering methods,plant biotechnology became indispensable for analyzing gene functions and relations.

Production of haploid and dihaploid plants has facilitated genetic mapping, thusproviding ground for the introduction of marker-assisted breeding.

Detailed knowledge of embryogenesis, cell division and differentiation, organo-genesis, etc. could not be possible without the use of well-characterized modelin vitro systems.

Interesting field was the use of (transgenic) root cultures for studying secondarymetabolism in plants. Plant cultures (cell, tissue, and organ) were successfully usedfor production of metabolites as well as for biotransformations of organiccompounds [57].

Tissue cultures have found their place as a model system to study mechanisms ofsalt stress in plants. Callus [58, 59] and protoplast-based [60] systems using tobacco


Fig.3

The

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proved to be a useful model. The classical in vitro selection approach is still used forobtaining stress-tolerant plant lines [61]. Particular success was demonstrated bycombination of in vitro selection with mutagenesis for producing plant material withnovel agronomically important traits [62].

Introduction of transgenic technologies allowed for further understanding of themechanisms of salt tolerance. Early works include evaluation of the role of proline[63], choline [64], betaine [65], and saccharides [66] as osmoprotectants.

3.2 Agriculture

Agriculture turned toward the plant biotechnology approaches when they becamerelatively mature. The key techniques were plant regeneration, embryo cultivation,and dihaploid line production (outlined in Fig. 4).

Classic tissue culture followed by regeneration of whole plants is a part of modernbreeding process. The possibility to select biological mutants in vitro was demon-strated by Carlson [67]. Later, Gengenbach and Green [68] used maize calluscultures for selecting pest-resistant clones.

Haploidity and especially the production of dihaploid plant lines had a significantimpact on crop breeding programs especially in combination with molecular markertechniques. First haploid embryo formation from in vitro culture of Datura anthers[69] was successfully repeated in tobacco [70, 71] and rice (Oryza sativa L.)[72]. The modern crop breeding benefited from the production of haploid wheatplants anther culture [73, 74], microspore culture [75], or wide hybridization withwild barley (Hordeum bulbosum L.) [76] or maize [77–79]. The main impact wasachieved by combining dihaploid plant production with molecular marker methods.This integrated approach is the keystone of marker-assisted breeding [80, 81].

The successful implementation of haploid culture strongly depends on excellenttissue culture expertise and deep knowledge of plant biology. The approach is alsoquite demanding in terms of labor and time. Nevertheless, the advantages for thebreeding programs are prevailing, and for many modern breeding entities, DH lineproduction is among the key techniques.

The embryo culture as a technique was introduced relatively early, but the firstpractical example of its use was for production of monoploids in barley [82]. Themethod itself still requires empirical optimization for each separate case. In terms ofexpertise and experience, it is even more demanding than working with haploidculture. On the other hand, embryo culture is the only tool allowing for efficientinterspecific and intergeneric hybridization in many species.

Today, the three classic approaches are an integral part of any modern platformfor crop breeding.

The link between plant biotechnology and agriculture faces novel challenges.From the very beginning of this intrinsic relation, plant biotechnology was assumedas a tool to provide better foods and guarantee agricultural performance. In April2016, the United Nations declared the start of an “International Decade on Nutrition”to meet the nutrition-related targets of the Sustainable Development Goals adopted


Fig.4

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by its member nations last year [83]. As part of the Sustainable Development Goals,a major aim is to end all forms of malnutrition by 2030, overarching the objectives ofensuring both food and nutritional security. Ending hunger, achieving food security,and improving nutritional quality of crop products will require significant efforts,substantial part of which will rely on state-of-the-art plant biotechnology methods.

Nowadays the calorie supply is not limiting factor in diets, but still phytonutrientdeficiencies continue to be prevalent [84]. It appears that the persistence of malnu-trition in specific sectors of the population, particularly children, coexists with anincrease in obesity and diet-related chronic diseases, such as diabetes. Thereforethere is an urgent need to develop a new generation of enhanced crops that canaddress diet-related chronic diseases. Plant biotechnology along with significantchanges in the ways food is transported and processed is among the solutions forcoping with this serious problem [85], also providing opportunities to addressseveral of the big challenges associated with the need for high-quality and enoughfood in the growing world population [86].

One of the key targets are the micronutrient deficiencies – iron, iodine, vitamin,etc. The micronutrient improvement is known as biofortification and can be achievedeither through conventional breeding as well as through genetic engineering[87]. Most popular example among the public for biofortified plant product (albeitGM product) is the “golden rice” [88]. “Golden rice” had demonstrated the potentialof transgenic technologies to design crops with improved nutrition properties as wellas the possibility to feed the rising population in the developing countries.

3.3 Transgenic Technologies and GMO

The ability to produce transgenic plants shaped the current status of plant biotech-nology as an important tool of modern science. Transgenic technologies are a blendof plant physiology, molecular biology, molecular genetics, chemistry, and physics.First example of directed plant cell transformation was obtained upon protoplastco-incubation with DNA [89]. The method for direct gene transfer into protoplastswas further optimized [90–92], but the cumbersome procedure forced the develop-ment of other methods.

3.3.1 AgrobacteriumIn the mid-1970s, research on Agrobacterium pathogenesis revealed the role ofTi-plasmid and the mechanisms of DNA delivery. In 1976 a successful integrationof the Ti-plasmid DNA from Agrobacterium tumefaciens in plants was demonstrated[93]. Soon after the cocultivation, transformation procedure was described, interest-ingly, for plant protoplasts [94].

While the potential of the system was already demonstrated, the experimentalprocedures were quite complicated and time-consuming. The requirements forextensive practical experience in microbial genetics also contributed to the limitationof the method to very few laboratories. It took several years of research to realize thatT-DNA could be separated from vir genes on a different vector [95, 96]. This


discovery simplified the cloning and transformation procedures and madeAgrobacterium-mediated transformation readily available for a broad range of lab-oratories, and first practice-oriented works appeared [97].

As a result, numerous transformation procedures were quickly developed andoptimized for different species, tissues, and cell types. Some of them were nichemethods, while others have received broad recognition. One such method was theuse of leaf discs for Agrobacterium-mediated transformation followed by plantregeneration [98].

After three decades of development and refinements, Agrobacterium-mediatedtransformation became a rather useful method in plant biotechnology. Simple searchwith “Agrobacterium-mediated plant transformation” at PubMed Central returnsnearly 10,000 referred full-text journal publications. Currently, gene transfer wasachieved to all economically important crops, all model plant species, and numerousspecies of medicinal or horticultural interest.

3.3.2 Particle BombardmentInitial experiments with Agrobacterium revealed that not all species were trans-formed with equal efficiency. For some important crops like wheat, it was impossibleto obtain any transgenics despite the efforts. The observed recalcitrance led to thedevelopment of several new approaches for transgene delivery. Among them thebiolistic gene transfer method [99] has received much appreciation and became defacto standard for generation of transgenic plants. The biolistic further simplifiedgene cloning and delivery techniques. It made possible to generate transgenic plantswith genes cloned in widely available plasmid vectors. The method allowed for genepyramiding. The method did not require extensive microbiological experience andalleviated the problems with Agrobacterium persistence in the transgenic plants.Most important feature was the ability to deliver foreign DNA to any type of cells ortissues without species-related restrictions.

3.3.3 Other MethodsThe introduction of foreign DNA in plant cells by electroporation was first demon-strated in 1985 by Fromm et al. [100].

The method was further optimized but never gained the popularity of both leadingmethods.

Another interesting alternative was based on treatment of plant protoplasts, cells,and tissue fragments with ultrasound [101]. The method was called acousticpermeabilization or sonoporation. It proved to be simple and less demanding interms of researcher qualifications, equipment, and consumables. Nevertheless, thepopularity was rather low.

Plant cell or tissue treatment with silicon carbide whiskers for DNA delivery wasfirst demonstrated by Kaeppler et al. [102]. The method proved to be efficient butwas largely abandoned due to safety reasons.

Microinjection was also employed for plant transformation purposes [92, 103],but the need for highly specialized equipment and corresponding skills kept thismethod out of reach to most research groups.


Similarly, the use of liposomes for transfection was also demonstrated [104] butwas not widely applied as compared to the transfection of animal cells.

Ultimately, plant transformation technologies had led to the creation of theagricultural biotechnology industry with annual global market value in the rangeof USD 20 billion. Part of this global market are the GM crops. Since theirintroduction in 1996, GM crops are grown in nearly 30 countries. Main growntransgenic crops are corn, soybean, cotton, and canola, while the transgenic traits arelimited to either Bt-toxin-based pest resistance or herbicide tolerance.

These limitations are purely for economic and political reasons. The GMO topic ishotly discussed and of constant public interest. While there is no convincing scientificevidence for harmful effect on the environment or human health [105, 106], the publicand political opinion in most countries had turned into a critical obstacle for furtherdevelopment of this most promising field of plant biotechnology. Most likely, anyfurther business-oriented development will rely on public perception.

On the other hand, at the laboratory, GM technologies had turned into an efficienttool to study fundamental biological processes. Transgenic technologies were suc-cessfully used for analyses of gene functions, different regulatory mechanisms,dynamics of cellular processes, cell and tissue differentiation, etc. Nowadays, genedelivery methods are basic for state-of-the-art gene editing methods.

The tight integration of transgenic technologies, classic plant biotechnologymethods, and omics technologies is often called plant engineering [107]. Uponimplementation within the breeding programs, plant engineering could become themain area of application and development of classic plant biotechnology.

3.3.4 Applications of GM PlantsGM technologies became one of the main lines of development for plant biotech-nology. One direction was the use of transgenic plant cells for production ofrecombinant proteins. First reports appeared shortly after the introduction and spreadof plant transgenic technologies. Interestingly, from the very beginning, plants hadattracted attention as protein producers. The reason was the relative simplicity of theexperimental design and product processing.

One group of the expressed proteins was of medical interest [108]. Further efforts[109] led to the realization that transgenic plant cultures were a viable and appro-priate system for production of compounds with pharmaceutical importance. Soonafter, transgenic plants were used for vaccine production. First examples have usedmodified plant viruses as vectors [110]. The terms “biopharmaceuticals” and“molecular farming” were then coined and soon first reviews on the topic appeared[111]. Several problems had to be solved like the glycosylation pattern [112] beforereleasing for therapeutic purposes. First commercial application of plant-basedvaccine was achieved by Dow AgroSciences in 2006 [113]. Recently, a plant cell-produced recombinant β-glucocerebrosidase for treatment of Gaucher’s disease wasapproved in the USA by FDA.

Transgenic technologies were further applied for production of novel protein-based materials like the spider silk protein [114]. Nowadays plant-based protein


production is recognized as a viable and sometimes cheaper alternative to microbialsystems.

The modification of plant metabolism was also employed for production ofethanol [115, 116], biodiesel [117, 118], as well as precursors for so-called bioplastic[119–121]. The implementation of plant metabolite engineering proved to be morecomplicated in terms of experimental design. Current developments in the field aredescribed in the recent review by Rusanov et al. [122].

Still however only single or stacked genes responsible for herbicide and insectresistance are dominating in the transgenic market. The GM technology is commer-cially exploited in four crops – soybean, maize, cotton, and rapeseed – and in the lastfew years in sugar beet. The attempt to introduce characters related to multigenefamilies (drought, cold, and salinity tolerance; nutrition qualities as fatty acids,vitamins, etc.) turns out not to be so easily regulated in the way their expressionand function to be as stable as the single or stacked genes.

Since 1996 until 2014, the cultivation of GM crops has been steadily increased. In2015 GM crops occupied 179.7 million hectares which is 1% less than in 2014. Ayear after the second decade of commercialization of biotech/GM crops in 2016,26 countries grew 185.1 million hectares of biotech crops – an increase of 5.4 millionhectares or 3% from 179.7 million hectares in 2015. Except for the 2015 adoption,this is the 20th series of increases every single year; and notably 12 of the 20 yearswere double-digit growth rates.

3.4 Plant Biotechnology for In Vitro Production in Bioreactors

Numbers of people have preferred to use plant natural products. Therefore, themarket for natural plant products has expanded, and this trend will continue.However, the production of plant bioactive substances is limited by climatic, envi-ronmental, and ecological reasons. This will lead to shortages of number plantproducts. These problems could be solved using plant in vitro technologies, whichare promising method for producing plant secondary metabolites. There are severalimportant advantages of plant in vitro technologies, mainly the independence fromclimatic conditions and the sustainable production process under controlled condi-tions. The main problem appeared during development of these technologies is withcultivation in bioreactors. For the successful industrial implementation of plantin vitro technology for bioactive substances production, an integrated approach forprocess optimization (including selection of productive lines, media optimization,development of suitable elicitation procedures, etc.) must be applied. This part of theprocess optimization is intensively studied and well documented [6, 8]. However thequestion about the process up-scaling is still reminded open, nevertheless, more than55 years of research in this area. Historical development of large-scale cultivation ofplant in vitro systems is very well summarized by Eibl and Eibl [123], Ruffoni andco-workers [124], and Yesil-Celiktas and co-workers [125].

To the best of our knowledge, in 1956 appeared the first patent for cultivation ofin vitro plant tissues [125]. The first scientific report about large-scale cultivation of


plant in vitro systems appeared in 1959. Telecke and Nickell successfully cultivatedtobacco cell suspension in 10-liter glass carboys [126]. A year later, the samescientists reported about new successful cultivation of plant cells suspension instainless steel bioreactor [127]. These two pioneer researches have been the funda-mental base for the next investigations of large-scale cultivation of plant cellsuspensions as the used bioreactor systems with continuously increased workingvolumes reached 20,000 liters in 1977 [123]. The first industrial process for produc-tion of bioactive plant secondary metabolite (shikonin by Lithospermumerythrorhizon) has been developed in 1983 [128]. Five years later ProfessorWestphal [123] reported about successful large-scale process for ginseng biomassproduction. Based on the promising results received by that time, it is followed byseries of successful, large-scale cultivations of various plant cell suspensions inbioreactors with a volume up to 50,000 liters – scopolamine by Duboisia sp.,podophyllotoxin by Podophyllum sp., protoberberine by Coptis japonica,rosmarinic acid by Coleus blumei, echinacea polysaccharides by Echinaceapurpurea, geraniol by Gramineae sp., arbutin by Catharanthus roseus, vanillin byVanilla planifolia, betacyanins by Beta vulgaris, etc. [127]. Leaders in the earlystages of developing the industrial application of plant biotechnologies are Japan’scorporations such as Japan Tobacco Inc., Meiji Seika, Nitto Denko Co., Ajinomoto,and Nippon Shinyaku, which developed their technologies in close collaborationwith academic research groups [125]. Industrial plant biotechnology continues itsdevelopment, and today Phyton Biotech located in Germany operates the world’slargest plant cell culture facility with bioreactors with working volumes of up to75,000 liters, where it produces taxanes (one of their major products) with an annualcapacity of 880,000 liters per year [129].

In parallel with industrial research, new constructive designs of bioreactors for thecultivation of plant cell suspensions are intensively developed and/or improved. Theaim of these studies was to optimize the mass exchange and minimize the mechan-ical stresses in the cultivation systems and, on this basis, to optimize the environ-mental conditions for the cultivation of plant cells. These studies have resulted in thecreation of a number of bioreactor systems that can be classified into several groups:stirred tanks, pneumatically agitated bioreactors, as well as disposable andnon-agitated bioreactors [123–125, 130].

It is understandable that studies on the bioreactor cultivation of plant in vitrosystems have begun with plant cell suspensions, as far as they can use the availablemicrobial biotechnology tools and cultivation algorithms. In the case with differen-tiated plant in vitro systems (such as hairy roots, shoots, and adventitious roots), it isnecessary to develop principally new bioreactor designs in relation to their specificmorphology, sensitivity to mechanical stresses, problems with the inoculation pro-cesses, gradients created, and subsequent limitation with respect to nutrients andgas-phase components. It seems the stirred tanks are not appropriate for cultivationof these types of in vitro systems, and therefore their industrial application is limitedby now [7]. To solve this problem, many investigations on laboratory and semi-industrial levels are reported. Bioreactor designs have been adopted to the specificmorphological characteristics of the differentiated plant in vitro systems, and


different scientific groups reported successful cultivations in bioreactors with new ormodified constructive designs, such as modified stirred tanks, cone balloon-typeairlift bioreactors, rotating drum bioreactors, nutrient mist bioreactors, radial flowbioreactors, wave bioreactors, modified bubble column with internal sections, etc.[7, 131, 132]. To the best of our knowledge, in 2006 for the first time, the temporaryimmersion cultivation bioreactor has been used for the production of bioactive plantsecondary metabolites (betalains by Beta vulgaris hairy roots) [133]. Later thistechnology has been applied to different types of differentiated plant in vitro systemsfor production of valuable molecules, as well as for solving of some fundamentalproblems with Agrobacterium transformation of plant cells [134–138]. In our opin-ion, the next direction of the research in the area of bioreactor cultivation ofdifferentiated plant in vitro systems should be development of so-called “low-cost”bioreactor systems, as well as improvement of disposable bioreactors. This willallow significant reduction in the initial investment and the next operating costs,which will open industrial implementation of the differentiated plant in vitro systemsfor bioactive substance production [139].

4 Future Developments

During the rise and affirmation of plant biotechnology as a defined scientificdiscipline, several trend lines of development were formed, gradually leading forthe amelioration of the DNA marker-assisted breeding and for the new developmentof such genome editing tools, oligonucleotide-directed mutagenesis, cisgenesis,intragenesis, omics technologies including phenomics (3-D imaging), etc. Theyare readily entering into the plant breeding programs for speeding up the efficiencyin both yield quality and quantity in the agricultural important crops.

The tissue culture techniques in combination with embryo culture or haploidproduction led directly to plant regeneration approaches, implemented in fundamen-tal research as well as modern crop breeding programs.

The validation of plant cell totipotency ultimately led to the development of planttransgenic technologies. In turn, genetic modifications brought to life a vast numberof new practical applications for basic research and commercial applications.

4.1 Integration with the Omics and Marker Technologies

The transition of classic plant biotechnology to its present state can be linked directlyto the rise of “omics” technologies and genomics in particular [140, 141]. Thegeneral development in chemistry and biology at the end of the twentieth centuryresulted in novel techniques, methods, and approaches, most of which were capableof generating enormous data. The resulted integration with mathematical and com-puting approaches (bioinformatics) led to a new evolutionary level which was coinedas “omics.”


Among the omics technologies applied in plant sciences, genomics was the firstone that emerged [142]. Still the genomics field is relatively young. A draft sequenceof the human genome was published in 2001 [143]. Ten years after the draft humangenome was published, Lander describes the progress since the start of the genomeproject. Some of this progress is the result of technical innovation. As Lander says,“The per-base cost of DNA sequencing has plummeted by 100,000-fold over thepast decade, far outpacing Moore’s law of technological advance in the semicon-ductor industry. The current generation of machines can read 250 billion bases in aweek, compared to 25,000 in 1990 and five million in 2000.” The speed of DNAsequencing changed drastically from about five million bases per week in 2000 to250 billion bases in 2010. Dramatic improvements in the sequencing machines haveled to plethora of new sequencing projects [144].

The first plant genome that was sequenced in 2000 was of Arabidopsis thalianaunder the Arabidopsis Genome Initiative 2000 [145]. It was chosen because of itsrelatively small genome and the fact that it has become the model plant for a lot ofstudies in plant science. In 2002 it was followed by publishing of draft of ricegenome [146, 147]. As of May 10, 2017, in NCBI, genome database (https://www.ncbi.nlm.nih.gov/genome/browse/) has reported the following number of entries:832 animal, 274 plant, 1132 fungal, 16,552 bacterial, and 7379 viral genomes.

The genome sequencing led to identification of huge numbers of molecularmarkers (e.g., SNPs). Their association with particular genes of interest can beintensively applied for genetic improvement by predicting breeding value[148]. This is an approach called marker-assisted selection [149]. There are differentstrategies for crop improvement, including the application of DNAmarkers. Some ofthem are the use of association mapping or genome-wide association studies(GWAS) [150, 151] and genomic selection [152, 153]. Another approach for geneticimprovement is applying of marker-assisted backcrossing [154, 155] when it comesto transfer of important genes from donor to elite variety [153] or into anotherspecies, generating in that way GMO.

Another application of genomics in the face of molecular markers, resulting fromgenome sequencing, is successfully used in the field of authenticity of food andagricultural products. Sequencing of more and more pathogen bacterial strain makesrelatively easy and accurate their identification in plant and animal diseases as wellas in food contamination.

The genome is quite stable, but the levels of mRNA, proteins, and metabolites canvary considerably depending on cells and tissues analyzed, on time, and on quitedifferent environment factors. In the need for their analysis, other “omics” technolo-gies have also been developed based on different technical innovations. For example,microarrays and RNA sequencing (RNA-Seq) [156] made high-throughput analysis ofmRNA expression feasible and led to the emergence of transcriptomics, which is partof the so-called functional genomics. Technological advances since the late 1990shave made transcriptomics a widespread discipline [157]. Today DNA microarraytechnology is available for many plants [158]. Transcriptomic studies became possibleeven for plants which genomes are not yet sequenced, through the development ofexpressed sequence tag (EST) libraries, cDNA collections, high-throughput transcript


https://www.ncbi.nlm.nih.gov/genome/browsehttps://www.ncbi.nlm.nih.gov/genome/browse

profiling, and next-generation sequencing (NGS) [159, 160]. The new sequencingtechnologies have set up the ground for genome-wide comprehensive transcriptomicsand analysis of RNAs [161].

In the post-genomic era of plant biology, the emerging challenge was to deter-mine the functions of all genes in the plant genome. RNA interference (RNAi) is oneof the functional genomics tools that have been developed to achieve this goal[162]. The phenomenon of gene silencing process was discovered accidentally inpetunia flowers [163]. RNAi also proved that it is a practical tool for plantresearchers toward improving crop varieties [164, 165].

RNAi has been used for enhancing the crop yield and productivity, for developingresistance against various biotic and abiotic stresses, and for nutritional improvementsof crops. MicroRNAs are key regulators of important plant processes like growth,development, and response to various stresses [166]. RNAi has also been used togenerate male sterility, which is valuable in the hybrid seed industry [167, 168].

Another powerful tool for crop improvement is proteomics [169]. The latestimprovements in proteomic field as well other advances in plant biotechnologytechniques offer new ways to stimulate the application of these technologies byplant scientists for crop improvement. The combination of genomics, proteomics,and other associated omics branches of biotechnology is showing their potential andeffectiveness to speed up the crop improvement programs worldwide [170]. Proteo-mics helps the investigations of abiotic and biotic stress tolerance mechanisms inplants. One of the important applications of the proteomic approaches is useful in thestudy of the molecular mechanism involved in the interaction between a plant and itspathogens [171].

Before the era of the current proteomic approaches and the advances in the 2-DEand the mass spectrometry machinery, proteins as molecular markers in the plantbreeding have been extensively used. Isoenzymes are commonly used proteinmarkers in plant breeding [172]. Practically any enzyme could be used as anisoenzyme genetic marker. As an example, pathogen resistance biochemical markershave been utilized to select salinity stress-tolerant plants [173].

Rapid advances in the technical developments for metabolite analysis have led tothe emerging of another omics field, namely, metabolomics [174]. Metabolite pro-filing is a valuable technology for improving our understanding of plant physiologyand biochemistry [175]. The rapid advances in the technologies for metaboliteprofiling made fact that hundreds and potentially thousands of metabolites beroutinely analyzed [176]. With the refining and expanding of these technologies, itwill allow analysis of a huge number of important micronutrients that will result inincreasingly exhaustive analysis of plant composition at an early stage in breedingprograms [177]. In addition metabolite-combined genotyping could be used toaccelerate the identification of genetic diversity and its further introduction intoplant breeding programs [178].

Major improvements in crop yield are needed to cope with population growth andclimate change. Despite that plant breeding benefited a lot from advances in geno-mics and proteomics, still profiling the crop phenome remains a major technicalbottleneck [179]. In continuation of exploration of genomics, among the several


omics technologies that emerged in the recent years is phenomics – the high-throughput analysis of phenotype [180, 181]. Unlike conventional quantitativegenetics, phenomics comprises an integrative approach and involves the detailedanalyses of physiological parameters and considers the genetic basis of the under-lying processes, as well as environmental impacts and agricultural practices.

The effect of “omics” technologies on plant biotechnology was clearly recog-nized [182], and currently its role is estimated to be of key importance for designingefficient breeding programs [183].

4.2 Integration with Gene and Genome ManipulationApproaches

Modern plant biotechnology successfully incorporated the most advanced methodsfor genome manipulation. With strong background of using transgenic technologies,the field received a significant boost for further development.

4.2.1 Gene EditingTransgenic technologies proved useful for both fundamental research and practicalpurposes but gained negative perception from the public. As a result, the search forother approaches that can change genome without insertion of foreign genes began. Inthe mid-1990s several possible alternatives were outlined. Most of them relied onintrinsic and fundamental cellular process of genetic recombination [184]. Next stepwas the identification of systems, capable of targeted induction of recombination at aspecific locus. This became possible due to the significant progress in molecular biology.Research on the structure of transcription factors led to the introduction of zinc fingerproteins for plant genome editing [185]. Molecular plant pathology provided informa-tion about specialized bacterial proteins – TALENs – capable to recognize extendedDNA sequences [186]. These systems proved efficient, but difficulties with the exper-imental design hampered extended adoption from most laboratories.

The situation has changed in 2013 when several groups almost simultaneouslypublished their results on plant gene manipulation

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