JASMONATES · 2017. 3. 21. · MeJA Untreated control Induction of jasmonate production in cell...

© 2015 American Society of Plant Biologists

JASMONATES


Plants are surrounded by many

enemies with a common goal...

Photo by Gilbert Ahlstrand courtesy USDA, Photo by Eric Erbe, digital colorization by Christopher Pooley, http://www.inra.fr/meloidogyne_incognita, D'Arcy, C. J. , D.

M. Eastburn, and G. L. Schumann. 2001. Illustrated Glossary of Plant Pathology. The Plant Health Instructor

Insects

Fungi

Bacteria

Oomycetes

Nematodes

... to “eat” them!

http://www.ars.usda.gov/is/graphics/photos/jul97/k7778-1.htm

http://www.ars.usda.gov/is/graphics/photos/mar05/k11077-1.htm

http://www.inra.fr/meloidogyne_incognita

http://dx.doi.org/DOI: 10.1094/PHI-I-2001-0219-01


Pathogens and pests cause

significant crop losses

Images courtesy Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org;

Charles Averre, North Carolina State University, Bugwood.org

Jasmonates and salicylates

are hormones that participate

in plant defense responses

Most plants are

resistant to most pests,

but a few organisms

cause tremendous

damage. 25% or more of

potential harvests can be lost

to insects and disease!

European corn borer

Ostrinia nubilalis

in its host Zea mays

Phytophthora capsici on

cucumber (Cucumis sativus)

http://www.forestryimages.org/browse/detail.cfm?imgnum=1234158

http://www.forestryimages.org/browse/detail.cfm?imgnum=1563084


Microorganisms are

(hemi)biotrophic or necrotrophic

Cell death

accompanies or

precedes

colonization by

necrotrophs

Biotrophs or hemibiotrophs

can live within their host

tissue without causing

(immediate) death

Toxin Pseudomonas

syringae in

intracellular space

Bestwick, C.S., Brown, I.R., Bennett, M., and Mansfield, J.W. (1997). Localization of hydrogen peroxide accumulation during the hypersensitive reaction of lettuce cells

to Pseudomonas syringae pv phaseolicola. Plant Cell 9: 209-221.

http://www.plantcell.org/cgi/reprint/9/2/209




Insects eat leaves, flowers, seeds

and roots and spread diseases

Boll weevil (Anthonomus grandis

grandis) on cotton (Gossypium hirsutum)

Leaf beetle (Phratora laticollis) on

European aspen (Populus tremula)

Image credits: Petr Kapitola, State Phytosanitary Administration, Bugwood.org ; Alton N. Sparks, Jr., University of Georgia, Bugwood.org

http://www.forestryimages.org/search/action.cfm?q=2113068



Jasmonates participate in plant

defenses to insects and necrotrophs

Jasmonates Salicylates

Transcriptional

responses

To a first

approximation, insects

and necrotrophs trigger

jasmonate production,

and biotrophs trigger

salicylate production


Jasmonates also contribute to

developmental and growth controls

Li, L., Zhao, Y., McCaig, B.C., Wingerd, B.A., Wang, J., Whalon, M.E., Pichersky, E., and Howe, G.A. (2004). The tomato homolog of CORONATINE-INSENSITIVE1 is required for the maternal control of seed

maturation, jasmonate-signaled defense responses, and glandular trichome development. Plant Cell 16: 126-143; Reprinted by permission from Macmillan Publishers Ltd. Thines, B., Katsir, L., Melotto, M., Niu, Y.,

Mandaokar, A., Liu, G., Nomura, K., He, S.Y., Howe, G.A., and Browse, J. (2007). JAZ repressor proteins are targets of the SCFCOI1 complex during jasmonate signalling. Nature 448: 661-665.

JA also controls: cell cycle, root

extension, leaf senescence,

stomata closure, and mutualistic

interactions....

Trichome formation Seed development Flower development

http://www.plantcell.org/cgi/content/full/16/1/126



http://www.nature.com/nature/journal/v448/n7154/full/nature05960.html




Lecture outline

• Jasmonate biochemistry

• Jasmonate signaling: • COI1- JAZ coreceptor

• JAZ repressors

• Transcriptional responses

• Jasmonates in whole-plant processes: • Responses to insects

• Responses to pathogens and other microorganisms

• Cross-talk in defense signaling

• Jasmonates in development and other functions


Jasmonates – synthesis, conjugation,

transport and degradation

Demole, E. Lederer, E., and Mercier, D. (1962) Isolement et détermination de la structure du jasmonate de méthyle, constituant odorant charactéristique de l’èssence de

jasmin. Helv. Chim. Acta 45: 675 -685.

Like other esters, methyl jasmonate smells good – it is the dominant scent

from jasmine flowers

“Jasmonate de méthyle”

O

CH2COOCH3

Methyl jasmonate was purified from Jasminum grandiflorium in 1962

http://onlinelibrary.wiley.com/doi/10.1002/hlca.19620450233/pdf




Jasmonates include jasmonic acid

(JA) and derivatives

JA-Ile

OH

(3R,7S)-jasmonic acid

a.k.a.

(+)-7-iso-jasmonic acid

Jasmonic acid

(JA) JA-Isoleucine

(JA-Ile)

OCH3

Methyl jasmonate

(MeJA)

Yan, J., Zhang, C., Gu, M., Bai, Z., Zhang, W., Qi, T., Cheng, Z., Peng, W., Luo, H., Nan, F., Wang, Z., and Xie, D. (2009). The Arabidopsis CORONATINE

INSENSITIVE1 protein Is a jasmonate receptor. Plant Cell 21: 2220-2236.

http://www.plantcell.org/cgi/content/abstract/21/8/2220




Jasmonates are produced preventively in

flowers and induced as a defense response

in other tissues

Gundlach, H., Müller, M.J., Kutchan, T.M., and Zenk, M.H. (1992). Jasmonic acid is a signal transducer in elicitor-induced plant cell cultures. Proc. Natl. Acad. Sci. 89: 2389-2393. (Photo from Wikipedia)

Wounding, pathogens or herbivores (or

molecules derived from them) trigger very

rapid accumulation of jasmonates

JA

MeJA

Untreated control

Induction of

jasmonate production

in cell suspension

culture (Rauvolfia

canescens, a

medicinal plant) by

adding yeast cell wall

elicitor

Rauvolfia canescens

http://www.pnas.org/content/89/6/2389.full.pdf+html



https://en.wikipedia.org/wiki/Rauvolfia_serpentina


JA accumulates in a circadian

pattern in phase with herbivory

Resistance to herbivory decreases when

Arabidopsis cycles out-of-phase to the insects

Reprinted from Goodspeed, D., Chehab, E.W., Min-Venditti, A., Braam, J., Covington, M.F. (2012). Arabidopsis synchronizes jasmonate-mediated defense with insect circadian behavior. Proc. Natl. Acad. Sci. USA 109: 4674-4677.

JA

SA

Herbivory

Hormone accumulation

JA and SA

cycle in

opposite

phasing

http://www.pnas.org/content/109/12/4674.abstract




Jasmonate synthesis occurs in the

plastid, peroxisome and cytosol

LOX

AOS AOC OPDA OPDA OPR3

β-oxidation

JA

MeJA JA-Ile

plastid peroxisome

Lipase

α-linolenic acid (18:3)

(in membrane)

ACX1

cytosol


Jasmonate precursors are derived

from membrane lipids

Ishiguro, S., Kawai-Oda, A., Ueda, J., Nishida, I., and Okada, K. (2001). The DEFECTIVE IN ANTHER DEHISCENCE1 gene encodes a novel phospholipase A1 catalyzing

the initial step of jasmonic acid biosynthesis, which synchronizes pollen maturation, anther dehiscence, and flower opening in Arabidopsis. Plant Cell 13: 2191-2209.

DAD1, DGL, GLA1

Lipolytic enzymes

are necessary for JA

synthesis and are

under tight regulation

MEMBRANE

Free fatty acid

Lipase Membrane

lipid

Free fatty

acid

α-linolenic acid





In Arabidopsis DAD1 and DGL lipases

are expressed in different tissues

Ishiguro, S., Kawai-Oda, A., Ueda, J., Nishida, I., and Okada, K. (2001). The DEFECTIVE IN ANTHER DEHISCENCE1 gene encodes a novel phospholipase A1 catalyzing the initial step of jasmonic acid biosynthesis, which synchronizes pollen

maturation, anther dehiscence, and flower opening in Arabidopsis. Plant Cell 13: 2191-2209; Reprinted from Hyun, Y., Choi, S., Hwang, H.-J., Yu, J., Nam, S.-J., Ko, J., Park, J.-Y., Seo, Y.S., Kim, E.Y., Ryu, S.B., Kim, W.T., Lee, Y.-H., Kang,

H., and Lee, I. (2008). Cooperation and functional diversification of two closely related galactolipase genes for jasmonate biosynthesis. Developmental Cell 14: 183-192 with permission from Elsevier.

DAD1 is

expressed in

anthers and is

necessary for

male fertility

In Arabidopsis the

DGL lipase is

expressed in rosette

leaves and involved

in wound response




http://dx.doi.org/doi:10.1016/j.devcel.2007.11.010




Jasmonates are derived from free

fatty acids Linolenic acid has 18 carbons and 3 double bonds

so is called an 18:3 octadecanoid

Another way to draw

linolenic acid


LOX is a lipoxygenase

Acosta I. F., and Farmer E. E. (2008). Jasmonates. In The Arabidopsis Book (The American Society of Plant Biologists), pp. 1-13.

Molecular oxygen is added to

the C13 position by 13-

lipoxygenase (LOX)

http://www.bioone.org/doi/full/10.1199/tab.0129




Allene oxide synthase (AOS)

catalyzes the first committed step

Allene oxide synthase

(AOS) dehydrates 13-

HPOT to form an

unstable allene epoxide

13-HPOT is 13(S)-

hydroxyperoxy-

octadecatrienoic acid






Allene oxide cyclase (AOC) defines

the stereochemistry

The unstable epoxide

spontaneously forms a

mixture of cis and trans

OPDA BUT, in the presence of

AOC it forms only the

cis form.






A parallel set of reactions starts with

a 16-carbon fatty acid

Reprinted from Schaller, A., and Stintzi, A. (2009). Enzymes in jasmonate biosynthesis - Structure,

function, regulation. Phytochemistry 70: 1532-1538 with permission from Elsevier.

These reactions take

place in plastids

O

COOH

cis-(+)-OPDA

O

COOH

dnOPDA

http://dx.doi.org/doi:10.1016/j.phytochem.2009.07.032




OPDA and dnOPDA move into the

peroxisome through a transporter

Reprinted from Schaller, A., and Stintzi, A. (2009). Enzymes in jasmonate biosynthesis - Structure,

function, regulation. Phytochemistry 70: 1532-1538 with permission from Elsevier.

The subsequent

reactions take

place in the

peroxisome

CTS / PXA1

O

COOH

cis-(+)-OPDA

O

COOH

dnOPDA





In the peroxisome, OPDA is first

reduced and then β-oxidized

Vick, B.A., and Zimmerman, D.C. (1984). Biosynthesis of jasmonic acid by several plant species. Plant Physiol. 75: 458-461.

OPDA reductase (OPR3)

β-oxidation is a multistep

process whose net result is the

removal of two carbon groups

Three cycles of β-

oxidation shorten the 18

carbon OPDA to the 12

carbon jasmonic acid

http://www.plantphysiol.org/cgi/reprint/75/2/458




β-oxidation occurs

by the action of

three enzymes

Repeat to

shorten chain

by two more

carbons

OPCL1 OPC-8:CoA ligase 1

Acyl-coenzyme A oxidase (ACX)

Multifunctional protein (MFP)

2-trans-enoyl-CoA hydratase

Multifunctional protein (MFP)

1-3-hydroxyacyl-CoA dehydrogenase

3-ketoacyl-CoA thiolase (KAT)

Li, C., Schilmiller, A.L., Liu, G., Lee, G.I., Jayanty, S., Sageman, C., Vrebalov, J., Giovannoni, J.J., Yagi, K., Kobayashi, Y., and Howe, G.A.

(2005). Role of β-oxidation in jasmonate biosynthesis and systemic wound signaling in tomato. Plant Cell 17: 971-986.





ACX1 acts during β-oxidation of JA

biosynthesis in the peroxisome

Schilmiller, A.L., Koo, A.J.K. and Howe, G.A. (2007). Functional diversification of acyl-coenzyme A oxidases in

jasmonic acid biosynthesis and action. Plant Physiol. 143: 812-824

ACX1 YFP

YFP

Expression in

pollen of ACX1,

encoding an

enzyme required

for jasmonate

biosynthesis

http://www.plantphysiol.org/content/143/2/812




LOX

AOS AOC OPDA OPDA OPR3

β-oxidation

JA

MeJA JA-Ile

plastid peroxisome

Lipase

α-linolenic acid (18:3)

(in membrane)

ACX1

Jasmonic acid is exported to the

cytosol for further modification


Jasmonic acid can be conjugated to

amino acids by JAR1

OH

JA JA-Ile

isoleucine

NH2

JAR1

Active

form

JAR1 is an amino

acid conjugase


JAR1 was identified as the

jasmonate-insensitive mutant jar1

Staswick, P.E., Su, W., and Howell, S.H. (1992). Methyl jasmonate inhibition of root growth and induction of a leaf protein are decreased in an Arabidopsis thaliana

mutant. Proc. Natl. Acad. Sci. USA 89: 6837-6840; Staswick, P.E., and Tiryaki, I. (2004). The oxylipin signal jasmonic acid is activated by an enzyme that conjugates it to

isoleucine in Arabidopsis. Plant Cell 16: 2117-2127.

Arabidopsis jar1 mutants produce jasmonic

acid but cannot make JA-Ile

jar1 mutants are also called far-red insensitive

219 (fin219) due to their phenotype in seedlings

(etiolation under far-red light)

Root growth on

MeJA is less

inhibited in jar1

mutants.

jar1 WT








Jasmonate can be reversibly

esterified to MeJA

JA-methyl

transferase

(JMT)

JA MeJA

Methyl

jasmonate

esterase (MJE)

MeJA is volatile and may be

produced for transport

COOH

O

COOCH3

O


MeJA production is developmentally

controlled and wound-induced

Seo, H.S., Song, J.T., Cheong, J.-J., Lee, Y.-H., Lee, Y.-W., Hwang, I., Lee, J.S., and Choi, Y.D. (2001). Jasmonic acid carboxyl methyltransferase: A key enzyme

for jasmonate-regulated plant responses. Proc. Natl. Acad. Sci. USA 98: 4788-4793.

JMT expression peaks at

anther dehiscence

JMT is induced by wounding or MeJA

Increased MeJA

production confers

protection against

necrotrophic

pathogens

http://www.pnas.org/content/98/8/4788.full




There are other forms of jasmonate

but their functions are not yet known

Swiatek, A., Dongen, W.V., Esmans, E.L., and Onckelen, H.V. (2004). Metabolic Fate of Jasmonates in Tobacco Bright Yellow-2 Cells. Plant Physiol. 135: 161-172.

JA introduced into

cultured cells is

incorporated into

several compounds –

possibly for storage

or degradation?

http://www.plantphysiol.org/cgi/content/full/135/1/161




WIPK and SIPK contribute to rapid

activation of JA synthesis enzymes

Kallenbach, M., Alagna, F., Baldwin, I.T., and Bonaventure, G. (2010). Nicotiana attenuata SIPK, WIPK, NPR1, and fatty acid-amino acid conjugates participate in the

induction of jasmonic acid biosynthesis by affecting early enzymatic steps in the pathway. Plant Physiol. 152: 96-106; Bonaventure, G. and Baldwin, I.T. (2010) New

insights into the early biochemical activation of jasmonic acid biosynthesis in leaves. Plant Signal Behaviour 5: 287-289.

WIPK – wound-induced

protein kinase

SIPK – salicylic-acid

induced protein kinase

These protein kinases

might activate enzymes

for very rapid JA

production Stroma

GLA

1

LOX

3

AOS

AOC

glycerolipids

18:3

13(S)-OOH-18:3 OPDA

peroxisome

?

SIPK NPR1 WIPK

OPDA

JA

?

EOT

wounding

chloroplast




https://www.landesbioscience.com/journals/psb/article/10713




Cytochrome P450 inactivates JA-Ile

Cytochrome P450 CYP94B3

mediates catabolism

and inactivation of JA-Ile

Koo, A.J., Cooke, T.F., Howe, G.A. (2011) Cytochrome P450 CYP94B3 mediates catabolism and inactivation of the plant hormone jasmonoyl-L-isoleucine. Proc. Natl. Acad. Sci. USA 108: 9298-9303.

Precursor Active Inactive

Loss-of-function

mutant cyp94b3-1

accumulates JA-Ile

http://www.pnas.org/content/early/2011/05/12/1103542108.full.pdf+html




Control of active hormone levels

LOX

AOS AOC OPDA

OPDA OPR3

β-oxidation

JA

MeJA JA-Ile

Lipase

*

* *

*

Lipases are

developmentally and

wound regulated

AOS and AOC are

wound-regulated (via

a wound-induced

protein kinase)

Entry into peroxisome

may be regulated

JAR1 activity

and JMT activity

are upregulated

by wounding

Jasmonate synthesis is

developmentally regulated as well

Ishiguro, S., Kawai-Oda, A., Ueda, J., Nishida, I., and Okada, K. (2001). The DEFECTIVE IN ANTHER DEHISCENCE1 gene encodes a novel phospholipase A1 catalyzing

the initial step of jasmonic acid biosynthesis, which synchronizes pollen maturation, anther dehiscence, and flower opening in Arabidopsis. Plant Cell 13: 2191-2209.





Synthesis, conjugation, transport

and degradation - summary •Jasmonate accumulation is developmentally regulated and

stimulated by wounding, some insects and some pathogens

•Jasmonates are oxylipins, derived from the oxidation of free fatty

acids

•Jasmonate synthesis occurs in plastids and peroxisomes.

Conjugation reactions occur in the cytosol

•JA-Ile is the most active compound whereas MeJA may be a

transport form

•JA-Ile is degraded by cytochrome P450 oxidases


Perception and signaling

•JA-Ile binding by the COI1-JAZ coreceptor

•Ubiquitination and degradation of JAZ

•Transcriptional activation by MYC2 and others

Gene expression

SCFCOI1

JA-

Ile

MYC2

BD

AD

JAZ

J

Z

MYC2

BD

AD


Coronatine is a bacterial compound

and powerful jasmonate mimic

Reprinted from Weiler, E.W., Kutchan, T.M., Gorba, T., Brodschelm, W., Niesel, U., and Bublitz, F. (1994). The Pseudomonas phytotoxin coronatine mimics octadecanoid

signalling molecules of higher plants. FEBS Letters 345: 9-13 with permission from Elsevier. Yan, J., Zhang, C., Gu, M., Bai, Z., Zhang, W., Qi, T., Cheng, Z., Peng, W.,

Luo, H., Nan, F., Wang, Z., and Xie, D. (2009). The Arabidopsis CORONATINE INSENSITIVE1 protein Is a jasmonate receptor. Plant Cell 21: 2220-2236.

MeJA

COR

Control

MeJA or

coronatine

(COR) induce

defense

compounds in

cultured cells of

California poppy

Coronatine is a toxin produced by

some pathogenic bacteria that

mimics jasmonate action and

structurally resembles JA-Ile

(3R,7S)-JA-Ile Coronatine

http://dx.doi.org/doi:10.1016/0014-5793(94)00411-0







The Arabidopsis mutant coi1 is

insensitive to coronatine and MeJA

Feys, B., Benedetti, C.E., Penfold, C.N., and Turner, J.G. (1994). Arabidopsis mutants selected for resistance to the phytotoxin coronatine are male

sterile, insensitive to methyl jasmonate, and resistant to a bacterial pathogen. Plant Cell 6: 751-759.

coi1

coi1

WT

WT

MeJA

COR

WT

coi1

Control





Tomato jai1 mutant is also deficient

in jasmonate responses

Li, L., Zhao, Y., McCaig, B.C., Wingerd, B.A., Wang, J., Whalon, M.E., Pichersky, E., and Howe, G.A. (2004). The tomato homolog of CORONATINE-INSENSITIVE1

is required for the maternal control of seed maturation, jasmonate-signaled defense responses, and glandular trichome development. Plant Cell 16: 126-143.

MeJA-resistant

Insect sensitive

Deficient in JA-induced transcription

JAI1 is the tomato

orthologue of COI1





Map-based cloning and a functional

assay were used to clone COI1

Functional assay for COI1:

COI1 activity is needed for JA-

or wound-induced activation of

PThi2.1-GUS reporter

construct.

(Thionins are JA-induced

defense proteins)

From Xie, D.-X., Feys, B.F., James, S., Nieto-Rostro, M., and Turner, J.G. (1998). COI1: An Arabidopsis gene required for

jasmonate-regulated defense and fertility. Science 280: 1091-1094. Reprinted with permission from AAAS.

http://www.sciencemag.org/cgi/content/full/sci;280/5366/1091




Genetic mapping led to two candidate genes and the

functional assay showed which has COI1 activity

From Xie, D.-X., Feys, B.F., James, S., Nieto-Rostro, M., and Turner, J.G. (1998). COI1: An Arabidopsis gene required for

jasmonate-regulated defense and fertility. Science 280: 1091-1094. Reprinted with permission from AAAS.

YES YES YES NO

Genetic complementation of

coi1 mutant by COI1 gene





Reprinted from Katsir, L., Chung, H.S., Koo, A.J.K., and Howe, G.A. (2008). Jasmonate signaling: a conserved

mechanism of hormone sensing. Curr. Opin. Plant Biol. 11: 428-435, with permission from Elsevier.

This similarity suggests a mode

of action!

COI1 is closely related to TIR1 and

other auxin receptors (AFB)

F-box proteins COI1 protein

family (jasmonate

coreceptors)

TIR1 / AFB

protein family

(auxin receptors)

Reprinted from Chico, J.M., Chini, A., Fonseca, S., and Solano, R. (2008). JAZ repressors set the rhythm

in jasmonate signaling. Curr. Opin. Plant Biol. 11: 486-494 with permission from Elsevier.

http://dx.doi.org/doi:10.1016/j.pbi.2008.05.004







The jasmonate receptor consists of

COI1 and JAZ co-receptors

Reprinted by permission from Macmillan Publishers Ltd. Nature: Sheard, L.B., Tan, X., Mao, H., Withers, J., Ben-Nissan, G., Hinds,

T.R., Kobayashi, Y., Hsu, F.-F., Sharon, M., Browse, J., He, S.Y., Rizo, J., Howe, G.A., and Zheng, N. (2010) Jasmonate perception by

inositol-phosphate-potentiated COI1-JAZ co-receptor. Nature 468: 400-405 copyright 2010.

COI1 JA-

Ile

The COI1-JAZ co-receptor has > 100

fold greater affinity for the ligand than

either COI1 or JAZ alone





COI1 is a component of the SCF

ubiquitin ligase complex SCFCOI1

CUL1

SKP1

F-box COI1

protein

COI1 F-box

protein

SCF complex

SCF ubiquitin ligase complex

(Named for SKP1, CUL1 and F-box

proteins)

(The auxin receptor TIR1 is a component of the SCFTIR1 complex)


Ubiquitin ligase complexes

ubiquitinate target proteins

The F-box protein recognizes

and binds to the target protein.

The complex then transfers

ubiquitin proteins to the target

CUL1

SKP1

Target Target

Ubiquitin

F-box

protein


Proteolytic targets are covalently

linked to ubiquitin

Ubiquitin by Rogerdodd

Ubiquitin Ubiquitin is a small (76 aa)

protein that targets proteins

for proteolytic degradation Target

http://en.wikipedia.org/wiki/File:Ubiquitin_cartoon-2-.png


Ubiquitinated targets are

proteolyzed by the 26S proteasome

26S proteasome

The proteasome

breaks down target

proteins and recycles

ubiquitin

Target


Jasmonate (like auxin) signaling

requires repressor degradation

Repressor

Transcriptional

activator

JAZ

MYC2

Aux/IAA

ARF

F-box

protein TIR1 COI1

hormone

Repressor

Transcriptional

activator

Auxin JA-Ile

JAZ

MYC2

Aux/IAA

ARF

+ hormone

In the absence of hormone, a

repressor interferes with a

transcriptional activator. The hormone

promotes an interaction between the

repressor and an F-box protein,

leading to repressor degradation and

transcriptional activation


JAZ proteins are repressors of

jasmonate signaling

Reprinted from Chung, H.S., Niu, Y., Browse, J., and Howe, G.A. (2009). Top hits in contemporary JAZ: An update on jasmonate

signaling. Phytochemistry 70: 1547-1559 with permission from Elsevier.





JAZ proteins are rapidly degraded in

the presence of jasmonates

Reprinted by permission from Macmillan Publishers Ltd. [Nature] Thines, B., Katsir, L., Melotto, M., Niu, Y., Mandaokar, A., Liu, G., Nomura, K., He, S.Y., Howe, G.A.,

and Browse, J. (2007). JAZ repressor proteins are targets of the SCFCOI1 complex during jasmonate signalling. Nature 448: 661-665. and Chini, A., Fonseca, S.,

Fernandez, G., Adie, B., Chico, J.M., Lorenzo, O., Garcia-Casado, G., Lopez-Vidriero, I., Lozano, F.M., Ponce, M.R., Micol, J.L., and Solano, R. (2007). The JAZ family

of repressors is the missing link in jasmonate signalling. Nature 448: 666-671 copyright 2007.

Control

+ jasmonate

Protein stability was

assayed in transgenic

plants expressing

JAZ-GFP or JAZ-GUS

fusions

JAZ-GFP








JAZ genes are transcriptionally

upregulated by jasmonates

Reprinted by permission from Macmillan Publishers Ltd. [Nature] Thines, B., Katsir, L., Melotto, M., Niu, Y., Mandaokar, A., Liu, G., Nomura, K., He, S.Y., Howe, G.A.,

and Browse, J. (2007). JAZ repressor proteins are targets of the SCFCOI1 complex during jasmonate signalling. Nature 448: 661-665.

Many JAZ genes are rapidly

induced by JA application

Similarly, transcription of the

Aux/IAA repressor genes are

rapidly upregulated by auxin





JAZ proteins have conserved Jas

and ZIM/TIFY domains

Chung, H.S., and Howe, G.A. (2009). A critical role for the TIFY motif in repression of jasmonate signaling by a stabilized splice variant of the JASMONATE ZIM-

domain protein JAZ10 in Arabidopsis. Plant Cell 21: 131-145.

The Jas domains facilitate

interactions with COI1 and

MYC2 proteins. The ZIM

domains (also called TIFY

domains) are dimerization

domains for interactions

with other JAZ proteins and

NINJA





In the jai3-1 mutant, the JAI3 protein

lacks a Jas domain

Reprinted by permission from Macmillan Publishers Ltd. [Nature] Chini, A., Fonseca, S., Fernandez, G., Adie, B., Chico, J.M., Lorenzo, O., Garcia-Casado, G.,

Lopez-Vidriero, I., Lozano, F.M., Ponce, M.R., Micol, J.L., and Solano, R. (2007). The JAZ family of repressors is the missing link in jasmonate signalling.

Nature 448: 666-671 copyright 2007.

A mutation changes the

encoded protein so it

lacks the Jas domain

and no longer interacts

with COI1.

Therefore it is not

degraded and continues

to repress JA responses

including root inhibition

by MeJA

jasmonate-

insensitive3

SCFCOI1

JA-

Ile





Plants expressing stabilized JAZ are

deficient in insect defenses

Chung, H.S., Koo, A.J.K., Gao, X., Jayanty, S., Thines, B., Jones, A.D., and Howe, G.A. (2008). Regulation and function of Arabidopsis

JASMONATE ZIM-domain genes in response to wounding and herbivory. Plant Physiol. 146: 952-964.

Plants with stabilized

JAZ proteins are

deficient in defense

responses. This is

clearly seen by the

growth rate of insects

feeding on them!





The JAZ ZIM domain facilitates

interactions with NINJA

Image by Hector Gomez

JAZ

Jas

ZIM NINJA

NINJA = Novel Interactor of JAZ

And NINJA interacts with TOPLESS......

http://www.openclipart.org/detail/63727


TOPLESS represses transcription in

absence of hormones

TPL

ARF

BD

III/IV

Aux/IAA

III/IV

EAR

TOPLESS binds directly to the

EAR domain of the Aux/IAA

repressors

TPL

JAZ

J

Z

NINJA

MYC2

BD

AD

EAR

TOPLESS binds indirectly to JAZ,

through NINJA


Direct targets of JAZ and downstream

regulation of transcription factors

Reprinted from Kazan, K., Manners, J.M. (2011). JAZ repressors and the orchestration of phytohormone crosstalk. Trends Plant Sci. 17: 22-31, with permission from Elsevier.

http://www.cell.com/trends/plant-science/retrieve/pii/S1360138511002305




The auxin signaling pathway

SCFTIR1

IAA

IAA

TPL

ARF

BD

III/IV

Aux/IAA III/IV

EAR

Aux/IAA III/IV

EAR

1. Auxin binds to SCFTIR1

and Aux/IAA



SCFTIR1

IAA

IAA

TPL

ARF

BD

III/IV

Aux/IAA III/IV

EAR


and Aux/IAA

2. Aux/IAA

ubiquitinated and

degraded by 26S

proteasome



BD

AD

SCFTIR1

IAA

IAA

TPL

ARF

BD

III/IV

Aux/IAA III/IV

EAR


and Aux/IAA

2. Aux/IAA

ubiquitinated and

degraded by 26S

proteasome

3. Degradation of

repressor permits

transcriptional

activation by ARF

transcription

factors ARF


The jasmonate signaling pathway

JA-Ile

TPL JAZ

J

Z

NINJA

MYC2

BD

AD

EAR

1.JA-Ile binds to SCFCOI1

and JAZ protein

SCFCOI1

JA-

Ile



SCFCOI1

JA-Ile

TPL JAZ

J

Z

NINJA

MYC2

BD

AD

EAR


and JAZ protein

2. JAZ

ubiquitinated and

degraded by 26S

proteasome

JA-

Ile



BD

AD

SCFCOI1

JA-Ile

TPL JAZ

J

Z

NINJA

MYC2

BD

AD

EAR


and JAZ protein

2. JAZ

ubiquitinated and

degraded by 26S

proteasome

3. Degradation of

repressor permits

transcriptional

activation by MYC2

transcription factors MYC2

JA-

Ile


jin1 is deficient in JA-induced

transcription and encodes MYC2

Berger, S., Bell, E., and Mullet, J.E. (1996). Two methyl jasmonate-insensitive mutants show altered expression of AtVsp in response to methyl jasmonate and

wounding. Plant Physiol. 111: 525-531; Lorenzo, O., Chico, J.M., Sanchez-Serrano, J.J., and Solano, R. (2004). JASMONATE-INSENSITIVE1 encodes a MYC

transcription factor essential to discriminate between different jasmonate-regulated defense responses in Arabidopsis. Plant Cell 16: 1938-1950.

AtVSP mRNA

MYC2 upregulates:

JAZ genes

LOX3 (JA synthesis)

VSP2 (wound response)

MYC2 MYC2








MYC2 downregulates some

pathogen-response genes

Lorenzo, O., Chico, J.M., Sanchez-Serrano, J.J., and Solano, R. (2004). JASMONATE-INSENSITIVE1 encodes a MYC transcription factor essential to discriminate

between different jasmonate-regulated defense responses in Arabidopsis. Plant Cell 16: 1938-1950.

MYC2





JA-regulated genes can be

positively or negatively regulated by

ethylene

Reprinted from Memelink, J. (2009). Regulation of gene expression by jasmonate hormones. Phytochemistry 70: 1560-1570 with permission from Elsevier.See also Zhu, Z., et al., (2011).

Derepression of ethylene-stabilized transcription factors (EIN3/EIL1) mediates jasmonate and ethylene signaling synergy in Arabidopsis. Proc. Natl. Acad. Sci. USA 108: 12539–12544.

PDF1.2 requires both

JA and ethylene

VSP1 is down

regulated by ethylene








The Mediator complex is a key

regulator of JA-dependent defense

Kidd, B.N., Edgar, C.I., Kumar, K.K., Aitken, E.A., Schenk, P.M., Manners, J.M. and Kazan, K. (2009). The Mediator Complex

subunit PFT1 is a key regulator of jasmonate-dependent defense in Arabidopsis. Plant Cell. 21: 2237-2252.

The Mediator

complex acts as a

bridge between RNA

polymerase II and

transcription factors

and fine-tunes

diverse regulatory

inputs

http://www.plantcell.org/content/21/8/2237.full




Core jasmonate signaling –

summary

BD

AD

SCFCOI1

JA-Ile

TPL JAZ

J

Z

NINJA

MYC2

BD

AD

EAR


and JAZ protein

2. JAZ

ubiquitinated and

degraded by 26S

proteasome

3. Degradation of

repressor permits

transcriptional

activation by MYC2

and other

transcription factors MYC2

JA-

Ile

There is also

extensive cross-talk

with other signaling

pathways!


Jasmonates in whole-plant

processes

•Responses to insects

•Responses to pathogens

and other microorganisms

•Cross-talk between JA and

SA pathways

•Jasmonates in development

and other processes

Mithofer, A., and Boland, W. (2008). Recognition of herbivory-associated molecular patterns. Plant Physiol. 146: 825-831.





Plants and insects have shared a

long period of co-evolution

> 400 mya

Image credit: L. Shyamal based on work by Bruce Tiffney

http://en.wikipedia.org/wiki/File:InsectPlantEvol.svg

http://www.ucmp.berkeley.edu/education/events/tiffney1.html


Plants are not passive victims

Direct responses – production of toxic or

anti-nutritive compounds (e.g. proteinase

inhibitors)

Indirect responses – volatile compounds

recognized by carnivorous or parasitoid

insects

Plants have constitutive and induced defenses

Induced responses can be direct or indirect

Constitutive – always present

Chemical – toxins, irritants (e.g.

cyanogenic glycosides, alkaloids,

tannins)

Physical – thorns, trichomes Linamarin, a cyanogenic

glycoside from cassava

Geocoris feeding on

Manduca eggs, attracted

by plant-emitted volatiles

Trichome photo credit: NRC-CNRC (Harry Turner) . Geocoris photo by M. Stitz from Allmann, S., and Baldwin, I.T. Insects betray themselves in nature to

predators by rapid Isomerization of green leaf volatiles. Science 329: 1075-1078 reprinted with permission from AAAS.

http://www.nrc-cnrc.gc.ca/eng/multimedia/trichome-cells-geranium.html



http://www.sciencemag.org/content/329/5995/1075.abstract




There are many kinds of arthropods

and feeding behaviors

Image credits: Syncroscopy; David Riley; N3v3rl4nd; Mithofer, A., and Boland, W. (2008). Recognition of herbivory-associated molecular patterns. Plant Physiol. 146: 825-831.

S. littoralis caterpillar feeding on

a barrel medic (Medicago

truncatula) leaf

Adult green peach aphid

(Myzus persicae) feeding on

a dill plant

Tomato leaf showing

damage caused by a

leaf miner

Beet armyworm (Spodoptera

exigua) damage to sweet

pepper (Capsicum annuum)

http://www.syncroscopy.com/syncroscopy/moreinfo.asp?page=CR53


http://en.wikipedia.org/wiki/File:Leaf-miner-tomato.jpg





Plants respond to oral secretions as

well as mechanical damage

Korth, K.L., and Dixon, R.A. (1997). Evidence for chewing insect-specific molecular events distinct from a general wound response in leaves. Plant Physiol. 115: 1299-1305.

Proteinase inhibitor gene

induction is much faster

when insect saliva or

regurgitate is present Plants recognize insect-

derived compounds as well as

mechanical damage





Plants produce proteinase

inhibitors that deter and weaken

herbivores

Green, T.R., and Ryan, C.A. (1972). Wound-induced proteinase inhibitor in plant leaves: A possible defense mechanism against insects. Science 175: 776-777.

Photo courtesy of Washington State University and Scott Bauer, USDA

In 1972, Green & Ryan found that

plants produce proteinase inhibitors

(PIs) in response to herbivory

47 202 A four-fold increase

in PIs was recorded

after 24 hours

Control plant Plant infested with herbivore

Clarence Ryan (1931-2007) was a

pioneer in the study of plant

responses to herbivorous insects

http://www.sciencemag.org/cgi/content/abstract/sci;175/4023/776



http://www.ars.usda.gov/is/graphics/photos/dec97/k4978-5.htm


Plants produce proteinase inhibitors

that interfere with digestion

Normally food that

enters the digestive

system is broken down

by digestive enzymes

so the nutrients can be

absorbed

MUNCH

MUNCH






Plants produce proteinase inhibitors

that interfere with digestion

Proteinase

inhibitors (PIs)

make insects sick

or even die

I feel sick






Jamonate signaling contributes to

defenses against herbivory WT Mutant without JA

When exposed to hungry

fly larvae, plants unable

to produce JA have low

rates of survival

McConn, M., Creelman, R.A., Bell, E., Mullet, J.E., and Browse, J. (1997). Jasmonate is essential for insect defense in Arabidopsis. Proc. Natl. Acad. Sci. USA 94: 5473-5477.





Jasmonates accumulate extremely

quickly after wounding

Glauser, G., Dubugnon, L., Mousavi, S.A.R., Rudaz, S., Wolfender, J.-L., and Farmer, E.E. (2009). Velocity estimates for signal

propagation leading to systemic jasmonic acid accumulation in wounded Arabidopsis. J. Biol. Chem. 284: 34506-34513.

Unwounded

plant

W (wounded)

part of leaf

U (unwounded)

part of leaf

When a leaf is crushed

with forceps, the level

of JA in the wounded

and unwounded part of

the leaf increases

within a minute

http://www.jbc.org/content/284/50/34506.abstract




The defense responses occurs in

unwounded leaves as well

336 103

Elevated PIs were

recorded from

unwounded leaves

as well suggesting

a mobile signal

Control plant Plant infested with herbivore –

extract from distant leaf






PI genes are induced by jasmonate

treatment, locally and systemically

Farmer, E.E., Johnson, R.R., and Ryan, C.A. (1992). Regulation of expression of proteinase inhibitor

genes by methyl jasmonate and jasmonic acid. Plant Physiol. 98: 995-1002.

244 103

6 2

Proteinase inhibitor gene

expression is induced by

Wounding or Methyl

Jasmonate.

MeJA vapor promotes PI

accumulation in exposed

leaves but also

unexposed leaves of the

same plant No MJ control





Systemic signaling does not involve

movement of JA-Ile but may involve

other jasmonates

Wang, L., Allmann, S., Wu, J., and Baldwin, I.T. (2008). Comparisons of LIPOXYGENASE3- and JASMONATE-RESISTANT4/6-silenced plants reveal that jasmonic

acid and jasmonic acid-amino acid conjugates play different roles in herbivore resistance of Nicotiana attenuata. Plant Physiol. 146: 904-915.

The nature of the mobile signal is

still not resolved – it may include:

•Jasmonates

•Hydraulic signals

•Ionic signals





Tomatoes and related plants

produce systemin, a peptide signal

Ryan, C.A., and Pearce, G. (2003). Systemins: A functionally defined family of peptide signals that regulate defensive genes in Solanaceae species. Proc. Natl. Acad.

Sci. USA 100: 14577-14580 copyright 2003 National Academy of Sciences USA.

Systemin is produced by

cleavage of a larger

protein prosystemin

http://www.pnas.org/content/100/suppl.2/14577.abstract




Expression of systemin in the

rootstock induces PIs in the scion

McGurl, B., Orozco-Cardenas, M., Pearce, G., and Ryan, C.A. (1994). Overexpression of the prosystemin gene in transgenic tomato plants generates a systemic

signal that constitutively induces proteinase inhibitor synthesis. Proc. Natl. Acad. Sci. USA 91: 9799-9802.

WT

35S:

Prosys

Initially these data

suggested that

systemin itself is the

mobile signal, but we

now believe

systemin’s role is only

at the wound site

220

273

WT

WT

13

15

http://www.pnas.org/content/91/21/9799.short




The COI1 receptor is required at the

systemic site but JA synthesis is not

WT

WT

13

15

35S:

Prosys

279

jai1

(COI1

receptor

mutant)

0

35S:

Prosys

spr-2

(JA

synthesis

mutant)

263

150

McGurl, B., Orozco-Cardenas, M., Pearce, G., and Ryan, C.A. (1994). Overexpression of the prosystemin gene in transgenic tomato plants generates a systemic

signal that constitutively induces proteinase inhibitor synthesis. Proc. Natl. Acad. Sci. USA 91: 9799-9802.





Systemin at the wound site generates or

amplifies the systemic signal

Li, L., Li, C., Lee, G.I., and Howe, G.A. (2002). Distinct roles for jasmonate synthesis and action in the systemic wound response of tomato. Proc. Natl.

Acad. Sci. USA 99: 6416-6421 copyright 2002 National Academy of Sciences USA.

The mobile signal (“X”) is

still being debated





Indirect responses include volatile

compounds that attract carnivorous

and parasitic insects

Tim Haye, Universität Kiel, Germany Bugwood.org; R.J. Reynolds Tobacco Company Slide Set and R.J. Reynolds Tobacco Company, Bugworld.org

And insects that

lay their eggs in

the herbivore,

which gets eaten

when they

hatch!

Volatiles attract

carnivorous

insects that eat

the herbivore

http://www.insectimages.org/browse/detail.cfm?imgnum=1445011





Charles Darwin had thoughts about

parasitic insects

I cannot persuade myself that a beneficent

and omnipotent God would have designedly

created the Ichneumonidae with the express

intention of their feeding within the living

bodies of caterpillars.

– Charles Darwin, 1860


Jasmonate mediates defenses

against necrotrophic pathogens

Photo credit Gary Loake

Arabidopsis plants infected with Botrytis cinerea

http://www.biology.ed.ac.uk/research/institutes/plant/pages/staff_pages/G_Loake_staffpage.htm


JA-insensitive plants are more

susceptible to pathogens

Thomma, B.P.H.J., Eggermont, K., Penninckx, I.A.M.A., Mauch-Mani, B., Vogelsang, R., Cammue, B.P.A., and Broekaert, W.F. (1998). Separate jasmonate-dependent

and salicylate-dependent defense-response pathways in Arabidopsis are essential for resistance to distinct microbial pathogens. Proc. Natl. Acad. Sci. USA 95: 15107-

15111 copyright 1998 National Academy of Sciences USA.

Alternaria

brassicicola

Botrytis

cinerea





JA-induces plant defenses against

pathogens

Photo credit: USDA

Peanut kernel infected by a soil fungus (Aspergillus

niger). Yellow-colored phytoalexin is locally produced by

the kernel tissues (arrow)

JA-mediated responses to

pathogens include production of

phytoalexins, and antimicrobial

peptides or proteins

http://www.ars.usda.gov/Research/docs.htm?docid=16814&page=3


Jasmonates protect plants through

induced resistance

Adapted from Frost, C.J., Mescher, M.C., Carlson, J.E., and De Moraes, C.M. (2008). Plant defense priming against herbivores: Getting ready for a different battle. Plant Physiol. 146: 818-824;

Conrath, U., Beckers, G.J.M., Flors, V., García-Agustín, P., Jakab, G.b., Mauch, F., Newman, M.-A., Pieterse, C.M.J., Poinssot, B., Pozo, M.J., Pugin, A., Schaffrath, U., Ton, J., Wendehenne, D.,

Zimmerli, L., and Mauch-Mani, B. (2006). Priming: Getting ready for battle. Mol. Plant-Microbe Interact. 19: 1062-1071.

Beneficial

bacteria or

fungi

Prior exposure to a pest, or

colonization with some non-

pathogenic bacteria can prime a

plant for enhanced responses.

Pseudomonas fluorescens

WCS417r primes the plant

to elicit a stronger, faster

response to MeJA




http://apsjournals.apsnet.org/doi/abs/10.1094/MPMI-19-1062




The mechanisms of priming are not

fully understood

Reprinted from Conrath U. (2011). Molecular aspects of defence priming. Trend Plant Sci 16: 524-531 with permission from Elsevier.

Perhaps signaling

molecules or transcription

factors increase in an

abundant, inactive state,

leading to an enhanced

defense response upon

subsequent attack





JA seems to play a role in

establishing mutualistic interactions

Reprinted from Hause, B., and Schaarschmidt, S. (2009). The role of jasmonates in mutualistic symbioses between plants and soil-born microorganisms. Phytochemistry

70: 1589-1599 with permission from Elsevier.

Arbuscular mycorrhiza Legume-rhizobia

symbiosis





Cross-talk between JA and SA-

mediated signaling

Jasmonates Salicylates

Remarkably, there is

considerable cross-

talk between JA and

SA signaling

pathways


Exogenous application of SA

enhances success of an herbivore

Cui, J., Bahrami, A.K., Pringle, E.G., Hernandez-Guzman, G., Bender, C.L., Pierce, N.E., and Ausubel, F.M. (2005). Pseudomonas syringae manipulates systemic plant

defenses against pathogens and herbivores. Proc. Natl. Acad. Sci. USA 102: 1791-1796 copyright 2005 National Academy of Sciences USA.

Trichoplusia ni (cabbage

looper) herbivory is enhanced

by SA and inhibited by MeJA





Salicylates repress jasmonate

signaling

Koornneef, A., and Pieterse, C.M.J. (2008). Cross talk in defense signaling. Plant Physiol. 146: 839-844.

JA-induced

SA-induced

JA

PDF1.2 PR-1

SA

JA induces expression of PDF1.2, but

in the presence of JA + SA the gene is

not activated. SA overrides JA.





Some insects induce SA responses

and repress JA responses

Zarate, S.I., Kempema, L.A., and Walling, L.L. (2007). Silverleaf whitefly induces salicylic acid

defenses and suppresses effectual jasmonic acid defenses. Plant Physiol. 143: 866-875.

Silverleaf whitefly nymphs

induce SA defenses which

suppress JA defenses,

increasing their survival - +

SA-induced

JA-induced

JA-induced

http://www.plantphysiol.org/cgi/content/abstract/143/2/866




Salicylates also make plants more

susceptible to necrotrophs

Spoel, S.H., Johnson, J.S., and Dong, X. (2007). Regulation of tradeoffs between plant defenses against pathogens with different lifestyles. Proceedings of

the National Academy of Sciences 104: 18842-18847 copyright National Academy of Sciences USA.

SA tends to

override JA-

mediated

responses

The necrotrophic fungus

Alternaria brassicicola

reproduces better on

Arabidopsis plants treated

with salicylic acid (SA)

JA

PDF1.2 PR-1

SA

http://www.pnas.org/content/104/47/18842.full.pdf




NONEXPRESSER OF

PR GENES1 (NPR1) is

activated by SA, and

interferes with JA

signaling

The Mediator complex

subunit16 (MED16) has

been implicated with this

signaling pathway

(downstream of NPR1) in

order to call RNA Pol II

and initiate transcription

NPR1 is a node through which SA

and JA pathways intersect

Spoel, S.H. et al. (2003). NPR1 modulates cross-talk between salicylate- and jasmonate-dependent defense pathways through a novel function in the cytosol. Plant Cell 15: 760-770. Zhang, X. et al. (2012). The

Arabidopsis Mediator complex subunit16 positively regulates salicylate-mediated systemic acquired resistance and jasmonate/ethylene-induced defense pathways. Plant Cell 24: 4294-4309.

RNA Pol II

MED16




http://www.plantcell.org/cgi/pmidlookup?view=long&pmid=23064320




Coronatine stimulates JA responses,

suppressing SA response

JA SA

Coronatine-

producing

bacterium

Defense Coronatine is an excellent

mimic of JA-Ile. Production of

coronatine significantly

enhances the pathogenicity of

bacteria that produce it


Different pathogens elicit different

“signal signatures”

De Vos, M., Van Oosten, V.R., Van Poecke, R.M.P., Van Pelt, J.A., Pozo, M.J., Mueller, M.J., Buchala, A.J., Metraux, J.-P., Van Loon, L.C., Dicke, M., and Pieterse,

C.M.J. (2005). Signal signature and transcriptome changes of Arabidopsis during pathogen and insect attack. Mol. Plant-Microbe Interact. 18: 923-937.

Plants are able to perceive the type of pathogen

or pest threatening them, and respond in

different, appropriate ways.

We still don’t understand much of this recognition

process





Ethylene and jasmonate pathways

confer specificity to the response

Lorenzo, O., Chico, J.M., Sanchez-Serrano, J.J., and Solano, R. (2004) JASMONATE-INSENSITIVE1 encodes a MYC transcription factor essential to discriminate

between different jasmonate-regulated defense responses in Arabidopsis. Plant Cell 16: 1938-1950.

Pathogens induce ethylene and

jasmonate production, and activate a

different subset of genes as those

induced by wounding or herbivory





Defense pathways coordinate with

ABA and developmental signals

Reprinted from Spoel, S.H., and Dong, X. (2008) Making sense of hormone crosstalk during plant

immune responses. Cell Host Microbe 3: 348-351 with permission from Elsevier.

http://www.cell.com/cell-host-microbe/abstract/S1931-3128(08)00157-1




Jasmonates integrate signals in

plant growth and development

Wasternack, C., and Hause, B. (2013). Jasmonates: biosynthesis, perception, signal transduction and action in plant stress response, growth and

development. An update to the 2007 review in Annals of Botany. Ann. Bot. 111: 1021–1058 by permission of Oxford University Press.

Root growth inhibition Tuber formation Senescence

Trichome formation Flower development

http://aob.oxfordjournals.org/content/111/6/1021.full




Jasmonates contribute to

developmental and growth controls

Li, L., Zhao, Y., McCaig, B.C., Wingerd, B.A., Wang, J., Whalon, M.E., Pichersky, E., and Howe, G.A. (2004). The tomato homolog of CORONATINE-INSENSITIVE1 is required for the maternal control of seed

maturation, jasmonate-signaled defense responses, and glandular trichome development. Plant Cell 16: 126-143; Reprinted by permission from Macmillan Publishers Ltd. Thines, B., Katsir, L., Melotto, M., Niu, Y.,

Mandaokar, A., Liu, G., Nomura, K., He, S.Y., Howe, G.A., and Browse, J. (2007). JAZ repressor proteins are targets of the SCFCOI1 complex during jasmonate signalling. Nature 448: 661-665.

Flower development

JA also controls: cell cycle, root

extension, leaf senescence,

stomata closure, and mutualistic

interactions....

Trichome formation Seed development








Qi, T., Huang, H., Song, S., and Xie, D. (2015). Regulation of jasmonate-mediated stamen development and seed production by a bHLH-MYB complex in Arabidopsis. Plant Cell. 27: 1620-1633

GA antagonizes positive effect of JA on

stamen development

JA regulates stamen development





Jasmonates and nutrients

Jasmonates promote

nutrient reallocation

away from leaves into

roots

Jasmonates promote

tuber formation in potato

Potassium-starved

Arabidopsis accumulate

jasmonates and are more

resistant to insects

There is a connection between jasmonates,

nutrients and energy reserves that may

contribute to defense and survival

Armengaud, P., Breitling, R., and Amtmann, A. (2010) Coronatine-Insensitive 1 (COI1) mediates transcriptional responses of Arabidopsis thaliana to

external potassium supply. Mol. Plant 3: 390-405.

http://mplant.oxfordjournals.org/content/3/2/390.short




Control of primary root development

involves both auxin and jasmonate

Reprinted from Kazan, K., Manners, J.M. (2011). JAZ repressors and the orchestration of phytohormone crosstalk. Trends Plant Sci. 17: 22-31, with permission from Elsevier;

Reprinted with permission from Hoffmann, M., Hentrich, M., Pollmann, S. (2011). Auxin-oxylipin crosstalk: Relationship of antagonists. J. Integr. Plant Biol. 53: 429–445.




http://onlinelibrary.wiley.com/doi/10.1111/j.1744-7909.2011.01053.x/full




Auxin and jasmonate act

antagonistically on leaf senescence

Reprinted from Jian et al. (2014). Arabidopsis WRKY functions as a node of convergence for jasmonic acid- and auxin-mediated signaling in jasmonic-acid induced leaf senescence. Plant Cell 26: 230-245

Ultimately, via WRKY57

JA induces leaf senescence

Auxin suppresses leaf senescence

http://www.plantcell.org/content/26/1/230.abstract




Ethylene and JA act antagonistically on

apical hook formation

Zhang, X et al. (2014). Jasmonate-activated MYC2 represses ETHYLENE INSENSITIVE3 activity to antagonize ethylene-promoted apical hook formation in Arabidopsis. Plant Cell. 26: 1105-1117.

EIN3 is induced by ethylene, and will

ultimately induce apical hook formation.

On the other hand, JA-induced MYC2

and EBF1 repress EIN3 activity,

inhibiting apical hook formation by

repressing expression of HLS1

http://www.plantcell.org/content/26/3/1105.long




Competition between GA and JA

Reprinted from Kazan, K., Manners, J.M. (2011). JAZ repressors and the orchestration of phytohormone crosstalk. Trends Plant Sci. 17: 22-31, with permission from Elsevier.

See also Hou, X. et al. (2010) DELLAs modulate jasmonate signaling via competitive binding to JAZ. Dev. Cell 19: 884-894

Normal

situation –

growth and

defense are

balanced

DELLAs competing

with MYCs for JAZs

binding while JAZs

competing with PIFs

for DELLA binding

Elevated JA -

defense

Elevated GA -

growth




http://www.cell.com/developmental-cell/retrieve/pii/S1534580710004776




Jasmonates integrate with light

signals via JAZ and and JAR1

Hsieh, H.L., and Okamoto, H. (2014). Molecular interaction of jasmonate and phytochrome A signalling. J Exp Bot. 65: 2847-2857 by permission of Oxford University Press; Robson, F., Okamoto, H., Patrick, E.,

Harris, S.-R., Wasternack, C., Brearley, C. and Turner, J.G. (2010). Jasmonate and phytochrome A signaling in Arabidopsis wound and shade responses are integrated through JAZ1 stability. Plant Cell. 22: 1143-1160.

http://jxb.oxfordjournals.org/content/65/11/2847.full







Ongoing questions

JA

MeJA JA-Ile

What signals trigger JA synthesis and

signaling pathways?

How does the plant discriminate

between threats?

What is the systemic signal?

What do the different JAZ proteins do?

How is the diversity of JA responses

controlled in specific organs and cell

types?

COI1 JA-

Ile


How does the plant prioritize its

stress and defense responses?

Pathogens (biotrophs)

Biotic stress

SA ABA

Stress-response

genes

SA-response

genes

Lorenzo, O., Chico, J.M., Sanchez-Serrano, J.J., and Solano, R. (2004) JASMONATE-INSENSITIVE1 encodes a MYC transcription factor essential to

discriminate between different jasmonate-regulated defense responses in Arabidopsis. Plant Cell 16: 1938-1950. Robert-Seilaniantz, A., Grant, M., Jones, J.D.G.

(2011). Hormone crosstalk in plant disease and defense: More than just JASMONATE-SALICYLATE antagonism. Annu. Rev. Phytopathol. 49: 317–343.




http://www.annualreviews.org/doi/abs/10.1146/annurev-phyto-073009-114447?journalCode=phyto




How can plant scientists prevent

crop losses to disease and insects?

Photo credit: ARS USDA

Most plants are resistant to most pests.

Nevertheless, pre- and post-harvest

crops losses can be devastating.

Understanding jasmonates helps plant

scientists and breeders enhance plant

resistance and optimize development

http://www.ars.usda.gov/is/graphics/photos/nov07/d939-1.htm

JASMONATES · 2017. 3. 21. · MeJA Untreated control Induction of jasmonate production in cell...

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