Lecture 5 Plant hormones 2014.ppt

8/16/2019 Lecture 5 Plant hormones 2014.ppt

1/35

Lecture 5

Plant hormonesand

Signal transduction

PLSC 452/552

1/23/14Department of Plant

SciencesNeal Stewart La


2/35

!rain teaser

• Little "ohnn# nails a sign $% cm o&the ground to a tree outside of hiscluhouse that sa#s 'no girlsallowed() *f the tree grows 12 cme+er# #ear, at what height will thesign e when Little "ohnn# returns as

!ig "ohnn# in 15 #ears-


3/35

.+er+iew

• Dene 'hormone) as a functionalcompound( 0hat is the function andimportance of hormones-

• now the maor plant hormones

• nderstand realworld application ofhormones

• *mportance of hormones for tissueculture introduction


4/35

0hat is a hormone-

• !iochemical which regulates growthased on iological and en+ironmentalin6uences

• S#non#ms Plant hormones, plantgrowth regulators 7P89s:,ph#tohormones

•9egulate growth and de+elopment

• ;oile throughout plant

•


5/35

;aor plant hormones

• =u>in ? 8ree@ au>einA to grow or increase

• C#to@inin ? c#to@inesis 7cell di+ision:

• =scisic acid ? ascission

• "asmonic acid ? found in asmine oil

• 8ierellic acid ? pathogen 8ierella

•


6/35

Binding plant hormones

.ser+ational

Darwin stumles on au>in – Noticed grass tips grow toward light

– 0ith tip growth responded to light

– 0ithout tip growth had no response

;utation screening 7a@a forward

genetics: – Dwarf plants are can e hormone decient


7/35=!9C teachin tools


8/35

8eneral hormoneiochemistr#

•

Present in all cells at +arious le+els• Classes of hormones wor@ in signal

cascades

– ormonereceptor interactions

– 9espond to a host of factors and iologicalneeds• =iotic

– 0ater stress

– Light – Nutrient decienc#

• !iotic – 8rowth

– De+elopment

– eri+ore stress


9/35

ormone ios#nthesis

;ade from four ios#nthetic pathwa#s – erpenoids

• =;P E *PP 7c#to@inins:

• Carotenoid rea@down 7ascisic acid:

• Diterpene 7gierellic acid:

• riterpene 7rassinosteroids:

–

Batt# acids 7asmonic acid: – r#ptophan 7au>ins:

– ;ethionine 7eth#lene:


10/35


11/35

=u>ins•

8ree@ au>einA to grow or increase• =pical dominance growth

• Cell elongation

• ormone le+el +er# important2, 4dichloropheno>#acetic

http//puchem(nci(nlm(nih(


12/35http//www(nsf(go+/news/newsFimages(sp-


13/35Taiz and Zeiger. 2002. Plant Physiology, 3rd Ed.


14/35

=u>in =pical dominance

http//users(rcn(com/@imall(ma(ultranet/!iolog#Pages/=/


15/35

C#to@inin

• C#to@inesis 7cell di+ision:

• =ccidentl# added degraded DN= tomedium

• .rganiHation and de+elopment of>#lem tissue

•

9esponse to light• Lateral growth of shoots

• .pen stomata


inetin


16/35

=pplication cotton spra#ing• =dding c#to@inins to #oung cotton increase

droughtresistance• =riHona ? 31I S cotton, highest #ield acre41


17/35


18/35

=u>in

C#to@inin

http//users(ugent(

e/Kpdeergh/pri/pri4eH%4(


19/35

=scisic acid 7=!=:

• .riginall# implicated in leaf and fruitascission

• *n+ol+ed in leaf senescence

• ;aintains seed dormanc# 7opposed to8=:

•

*n+ol+ed in stomata regulation 7closes:• Single hormone unit

http//puchem(nci(nlm(nih(go


20/35

http//www(ri@enresea

rch(ri@en(p/eng/research 121


21/35


22/35


23/35

http//par@(itc(uto@#o(ac(p/iotecres

"asmonic acid Pathogen response


24/35

8ierellic acid

•.riginall# found in 8ierella 7ricepathogen: – 9esponsile for Mfoolish seedling

phenomenon – ninhiited growth until rea@ing

• *n+ol+ed in cell elongation

•

Blowering and seed germination



25/35

;odication of 8= in rice

;i#a@o eguchiana@a 2%%5 Nature 437, $3$O

Spra#ing 8= for increased fruit


26/35

Spra#ing 8= for increased fruit#ield

8= induces fruitingin asence of seed

http//www(e>tension(org/pages/31%/usingplantgrowthregulatorstoincreasethesiHeoftalegrape


27/35


28/35

Con+ersational Plants-

•


29/35

!rassinosteroids

•

Stress responses – Switchgrass suspension cells ha+e minor

amounts of lignin 7small amounts of monolignols:

– =ddition of rassinolide induces normallignin formation and composition

• Stem elongation

• Seed germination

• Pollen tue growth

• Cell di&erentiation control

!rassinolide


. i f h


30/35

Brassinosteroid

mutant

Bishopp A et al. Development 2006;133:1857-186

.+er+iew of hormonemutants

!th"lene

mutant

#ro$n in dar%

&"to%inin

mutant

&"to%inin

mutant

'loser loo%

A(s'isi' a'id

mutant


31/35

ormones 7P89: pathwa#s

• P89s wor@ in comple> cascades toproduce signals – S#nergistic

– =natognistic

• ariet# of actions in cell

– 8ene transcription – Protein degradation

http//chriscarterart(wordpress(com/2%1%/%5/%$/mothersda#2/mi@adoplantwatercolors@etchchriscarter%5%$1%/


32/35

Arabidopsis histidine kinase sensing and signaling; 2) A histidine


33/35

htt //molio(m h(har+ard(edu/sheenwe/c to@inin si nalin (ht

Arabidopsis histidine kinase sensing and signaling; 2) A histidine

phosphotransferase protein n!lear translo!ation; 3) A response reglation

trans!ription a!ti"ation; and #) a negati"e feedba!k loop throgh !ytokinin$

ind!ible A%% gene prod!ts.


34/35


35/35

Lecture summar#

• ormones are iochemicals thatregulate plant growth ased oniological and en+ironmental cues

• =u>in and c#to@inin are @e# for plantgrowth

• =iotic and iotic stress response is

regulated # hormones• Cell signaling is regulated # specic

receptors on cell memranes

Lecture 5 Plant hormones 2014.ppt

Documents

Transcript of Lecture 5 Plant hormones 2014.ppt