JASMONATE AND ETHYLENE SIGNALS IN PLANT DEFENCE

Roberto SolanoDpto. Genética Molecular de PlantasCentro Nacional de Biotecnología (CNB-CSIC)e-mail: rsolano@cnb.uam.es

Hormonal signalling in plant defence against pathogens

Pathogens

ET JA

PRs(acidic)

SA

npr1

PDF, b-CHI(basic PRs)

Biotrophs Necrotrophs

JR1JR2VSP

JAOGAs

C2 H4 Systemicsignal

JR1JR2VSP

WOUNDED LEAF SYSTEMIC LEAF

CKWR3

MECHANICALDAMAGE

ETR1EIN2EIN3

COI1

ET prevents JA-mediated gene expression in the wound response

Rojo et al., 1999

ET mediates cell-death in response to O3

Rao et al., 2002

JA prevents ET-mediated cell-death in response to O3

Overmyer et al., 2000

JA prevents ET-induced hook curvature

Ellis and Turner, 2002

Pathogens(necrotrophs)

ET JA

ERF1(other ERFs) ?

PRs

disease resistance

Lorenzo et al., 2003

Botrytis cinerea induces ERF1 expression

JA regulates ERF1 expression

ERF1 expression requiresET and JA pathways simultaneously

ERF1 restores PR expression in coi1 and ein2

ERF1 increases resistance to necrotrophic fungi

Pathogens(necrotrophs)

ET JA

ERF1(other ERFs) ?

PRs

disease resistanceLorenzo et al., 2003

Disection of Arabidopsis-Pythium interaction

+

Pathogens(necrotrophs)

ET JA

ERF1(other ERFs) ?

PRs

disease resistance

Lorenzo et al., 2003

Genetic disection of the JA signaling pathway

Described Mutantscoi1

Chromosome IIjin4/jar1

Chromosome Ijin1

WT ein3

50µMJA

WTcoi1

JA insensitive mutants (jai)

Map position of jai mutants

cM

25 jai4 (1 alleles)jai3

(2 alleles)50

75

100

125

150

I II III IV V

jai1(5 alleles)

jai2 (3 alleles)

coi1jar1

jai5 (7 alleles)

jin1

jai4 is more susceptible to Botrytis

0

20

40

60

80

100

Col-0edm

1ein

3-3jai4

-1coi

1-1

0 1 2 3 4

Col-0

edm1

ein3-3

jai4-1

coi1-1

Disease rating%

Infe

cted

leav

es

jai4 is insensitive to auxins

ein3-3 Col-0 jai4 coi1 axr1-12 aux1-7

50µM JA

0,3µM NAA

Expression of auxin-regulated genes in jai4

C JA Ax C JA Ax C JA Ax C JA Ax C JA Ax C JA Axein3-3 jai4-1 Col-0 jin1 axr1-12edm1

IAA2

IAA4

JR1

JR3

VSP2

jai4 interacts genetically with axr1

Col-0ein3-3 jai4-1 jai4-1;axr1 axr1 edm1;axr1 edm1

NAA

Col-0ein3-3 jai4-1 jai4-1;axr1 axr1 edm1;axr1 edm1 coi1

JA

Positional cloning of jai4

Chromosome IV CIW6DET1

F25I24 F8L21F25E4

T5C23T22B4

SGT1b

TGG(Trp)

TAG(stop)

TRP CS SGS

The SCF ubiquitin ligase model

Gray, 2002

Sgt1a is insensitive to low JA concentrations

WS Col-0jai4-1 ein3-3 coi1 edm1rar1 sgt1a

50 µM JA

5 µM JA

JA insensitive mutants (jai)

Mutations in JIN1 increase resistance to necrotrophic fungi

Disease rating

0

20

40

60

80

100

Col-

0ja

i1-2

jai1

-3jin

1co

i1-1

ein3

-3ja

i1-1

jai1

-2ja

i1-4

jai1

-5

% in

fect

ed le

aves

0 1 2 3

Col- 0 ein3-3

P. cucumerina

Disease rating

0

20

40

60

80

100

Col-

0ja

i1-2

jai1

-3jin

1co

i1-1

ein3

-3ja

i1-1

jai1

-2ja

i1-4

jai1

-5

% in

fect

ed le

aves

0 1 2 3

Col- 0 ein3-3

B. cinerea

Expression profiling of jin1 in response to JA

WT vs. jin1JA :

Expression profiling of jin1 in response to JA

(WT vs. jin1) JAPathogen Defence

(PDF, CHI, Hevein)

Wounding(VSP, LOX, MBP)

Differential regulation of JA-response genes by JIN1

jin1-2 jin1-1

Wounding-responsegenes

Pathogen-responsegenes

Positional cloning of jin1

Chromosome I AIG1UFO

F27G20 T9G5F6N18

F9L11T9L6

AtMYC2

T16O9F10C21F5D14F3C3

bHLHAcidic

S588N∆ jin1

W103Zjai1-1

W194Zjai1-2

G228Ejai1-3

R239Zjai1-4

W266Zjai1-5

T- DNA3 SALK_061267

T- DNA2 SALK_040500

T- DNA1 SALK_039235

ZIP

T-DNA insertions in AtMYC2 induce JA insensitivity

SALK_061267SALK_040500SALK_039235

jin1-2 (jin1-7) (jin1-8)WTT-DNA1 T-DNA2 T-DNA3

jin1-1;35S:AtMYC2

jin1-

2

jin1-2;35S:AtMYC2

jin1-

1

JA

(5µM)

(10µM)

Col-0;35S:AtMYC2

Col-0

1 2 1 2 1 2

AtMYC2

AtMYC2 induces JA hypersensitivity

jin1-

2

jin1-

1

Col-0

1 2 1 2 1 2

rDNA

JA (µM) 5 10AtMYC2 is a nuclear protein

Col- 0

jai1-2

jin1

35S:GFP 35S:AtMYC2:GFP 35S:AtMYC2∆:GFP

bHLH ZIP

AtMYC2 expression is regulated by Wounding, JA and ABA

-1

ET prevents JA-mediated gene expression in the wound response

JR1JR2VSP

JAOGAs

C2 H4 Systemicsignal

JR1JR2VSP

WOUNDED LEAF SYSTEMIC LEAF

CKWR3

MECHAN ICALDAMAGE

ETR1EIN2EIN3

COI1

Rojo et al., 1999

ERF1 represses wound response downstream AtMYC2

Pathogens(necrotrophs)

ET JA

ERF1

Pathogen-response genes

Wounding(mechanical/insect/hervibory)

AtMYC2

(ABA)?

COI1

Wound-response genes

SGT1b

Aknowledgements

CNB (lab. 317)

Marta Godoy

Genomics facility CNB

Oscar LorenzoJA signalling

Irene López-VidrieroJosé M. ChicoCatalina del Moral

Bruce AdiePythium

Luis López

Genomics facility DIO (CNB)Gloria García-Casado

Julián PérezGenomics

Sylvia Gutiérrez

ConfocalCristina Merino

José J. Sánchez-Serrano

CNB (lab. 316)