Introduction to Botany. Lecture 11herba.msu.ru/shipunov/school/biol_154/2010_2011/lec_11.pdf ·...
Transcript of Introduction to Botany. Lecture 11herba.msu.ru/shipunov/school/biol_154/2010_2011/lec_11.pdf ·...
Leaf anatomy
Introduction to Botany. Lecture 11
Alexey Shipunov
Minot State University
September 22th, 2010
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Leaf anatomy
Outline
1 Leaf anatomyTypical leafEcological adaptations of leaves
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Leaf anatomyTypical leafEcological adaptations of leaves
General leaf anatomy
Epidermis with stomataMesophyllVascular bundles, or veins
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Leaf anatomyTypical leafEcological adaptations of leaves
Lilac (Syringa vulgaris) leaf in cross-section
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Leaf anatomyTypical leafEcological adaptations of leaves
Epidermis and stomata
Covered with cuticleInclude stomata with guard cells and (often) subsidiarycells and trichomesOpening of stomata is a result of exchange of K+, osmosisand uneven cell wallLower epidermis in most cases contain more stomata
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Leaf anatomyTypical leafEcological adaptations of leaves
Stomata as balloons
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Leaf anatomyTypical leafEcological adaptations of leaves
Mesophyll
Palisade mesophyll consists of tightly arranged elongatedcells with less chloroplasts*Spongy mesophyll consists of loosely attached cells rich ofchloroplasts*
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Leaf anatomyTypical leafEcological adaptations of leaves
Palisade and spongy cells
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Leaf anatomyTypical leafEcological adaptations of leaves
Veins/vascular bundles
Phloem typically faces downwards, xylem—upwardsBundles of C4-plants have additional bundle sheath cells
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Leaf anatomyTypical leafEcological adaptations of leaves
Bundle sheath cells
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Leaf anatomyTypical leafEcological adaptations of leaves
Plants and water
Xerophytes: sclerophytes and succulents (stem and leaf)MesophytesHygrophytesHydrophytes
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Leaf anatomyTypical leafEcological adaptations of leaves
Leaf succulent (Crassula argentea)
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Leaf anatomyTypical leafEcological adaptations of leaves
Xerophyte leaf—needle of pine (Pinus contorta)
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Leaf anatomyTypical leafEcological adaptations of leaves
Plants and light
SciophytesHeliophytes
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Leaf anatomyTypical leafEcological adaptations of leaves
Sciophyte and heliophyte
Oxalis acetosella and Sylphium laciniatum
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Leaf anatomyTypical leafEcological adaptations of leaves
Plants and soil
Halophytes (accumulate, excrete or avoid NaCl)Nitrate halophytes (grow on soils rich of NaNO3)Oxylophytes (grow on acidic soils)Calciphytes (grow on chalk soils rich of CaCO3)
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Leaf anatomyTypical leafEcological adaptations of leaves
Leaf of salt-accumulating halophyte
Atriplex prostrata
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Leaf anatomyTypical leafEcological adaptations of leaves
Plants and substrate
Psammophytes (grow on sand)Petrophytes (grow on rocks)Rheophytes (grow in fast springs)
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Leaf anatomyTypical leafEcological adaptations of leaves
Rheophyte
Rhyncholacis penicillata from Venezuela
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Leaf anatomyTypical leafEcological adaptations of leaves
Plants and methabolism
MycoparasitesHemiparasitesPhytoparasites (root and stem)
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Leaf anatomyTypical leafEcological adaptations of leaves
Mycoparasite
Triuris hyalina from South America
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Leaf anatomyTypical leafEcological adaptations of leaves
Hemiparasite
Krameria parvifolia from southern Texas
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Leaf anatomyTypical leafEcological adaptations of leaves
Root parasite
Hydnora africana from South Africa
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Leaf anatomyTypical leafEcological adaptations of leaves
Stem parasite 1
Cuscuta europaea from Germany
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Leaf anatomyTypical leafEcological adaptations of leaves
Stem parasite 2
Pilostyles thurberi from southern California
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Leaf anatomyTypical leafEcological adaptations of leaves
Summary
Osmotic processes in guard cells result in opening andclosing of stomataThe differentiation of mesophyll to palisade and spongycells helps to acquire different types of light rays
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Appendix For Further Reading
For Further Reading
Th. L. Rost, M. G. Barbour, C. R. Stocking, T. M. Murphy.Plant Biology. 2nd edition.Thomson Brooks/Cole, 2006.6.1–6.4.
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