Transcript
Page 1: GIGANTEA-mediated salt stress sigggpnaling in plantelearning.kocw.net/.../wcu/2013/KyungSang/KimWoeyeon1/1.pdf · 2013-07-24 · GI mutant exhibits increased salt tolerance WT gi-1

GIGANTEA mediated salt stress GIGANTEA-mediated salt stress signaling in plant g g p

(식물에서 자이겐티아에 의한 내염성 기작 조절)

Woe Yeon Kim

World Class University Program and Department of Applied life chemistry Department of Applied life chemistry,

Gyeongsang National University

Page 2: GIGANTEA-mediated salt stress sigggpnaling in plantelearning.kocw.net/.../wcu/2013/KyungSang/KimWoeyeon1/1.pdf · 2013-07-24 · GI mutant exhibits increased salt tolerance WT gi-1

GIGANTEA (GI)GIInput

- photomorphogenesis

GIGANTEA (GI)

OscillatorLHY TOC1

photomorphogenesis, - photoperiodic flowering regulation- circadian clock regulation

OscillatorLHYCCA1

TOC1g

- excess starch accumulation- alterations to sucrose metabolism

lt d iti it t GI

- altered sensitivity to Light, Cold, and Oxidative stress

CO

Output(photoperiodicfl in C d f 1173

FTflowering pathway)

~ Composed of 1173 a.a.

Page 3: GIGANTEA-mediated salt stress sigggpnaling in plantelearning.kocw.net/.../wcu/2013/KyungSang/KimWoeyeon1/1.pdf · 2013-07-24 · GI mutant exhibits increased salt tolerance WT gi-1

GIGANTEA controls the circadian clock and time of flowering through protein stabilizationtime of flowering through protein stabilization

Modified from Deng (2012) Trends in Plant Science

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Salt stress inhibits plant growth and delays p g yflowering time in Arabidopsis plants.

Xua Li et al. (2007) Plant Growth Regul.

Page 5: GIGANTEA-mediated salt stress sigggpnaling in plantelearning.kocw.net/.../wcu/2013/KyungSang/KimWoeyeon1/1.pdf · 2013-07-24 · GI mutant exhibits increased salt tolerance WT gi-1

Floral transition in Arabidopsis

GI

TOC1

ZTL GI FKF1

CDF1

CO

LFY

Modified from Blázquez et al. (2001) EMBO reports

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CO plays a key role in salt-induced late floweringp y y f g

Xua Li et al. (2007) Plant Growth Regul.

Page 7: GIGANTEA-mediated salt stress sigggpnaling in plantelearning.kocw.net/.../wcu/2013/KyungSang/KimWoeyeon1/1.pdf · 2013-07-24 · GI mutant exhibits increased salt tolerance WT gi-1

Does GI play a role in salt induced late flowering ?

300 mM25 mM

20

g tim

em

ber)

25 mM

10

Flow

erin

g(le

af n

um

WT GI-OXgi-1 WT GI-OXgi-10 WT GI-OXgi-1

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GI is degraded upon salt stress

Transcript 0 12 24 (hr)

Protein 0 12 24 (hr)

3 ControlNaClMG132NaCl+MG132n

(fold

)

( )GITUBGI-HA

( )Control

NaCl2

NaCl+MG132

GI p

rote

in

MG132NaCl+MG132

0

1

Rel

ativ

e G

00 12 24

Time (hr)

R

Page 9: GIGANTEA-mediated salt stress sigggpnaling in plantelearning.kocw.net/.../wcu/2013/KyungSang/KimWoeyeon1/1.pdf · 2013-07-24 · GI mutant exhibits increased salt tolerance WT gi-1

GI mutant exhibits increased salt tolerance

WT GI-OX gi-1

0 mM

A

ed

B

4

5150mM NaCl

ht (g

)

0 mM

plan

ts T

reat

ew

o w

eeks

2

3

resh

wei

g150 mM

250 Mw

eeks

old

pith

sal

t for

tw0

1Fr

WT GI-OX gi-1

250 mMTh

ree w

Page 10: GIGANTEA-mediated salt stress sigggpnaling in plantelearning.kocw.net/.../wcu/2013/KyungSang/KimWoeyeon1/1.pdf · 2013-07-24 · GI mutant exhibits increased salt tolerance WT gi-1

Salt stress tolerance in Plants

[Ca 2+]ext

High [Na +]

SOS1

H +Sodium efflux

[Ca 2+]int

PM

Ion SOS3 SOS2

SOS1

Na +

Na +

[ ]int

homeostasisSalt stress signaling

H + H +

Ca 2+

V-ATPasePPase

MYC/MYB/AREB/DREB2A

NU

Compartmentation

NHX

VacuoleH +

N + 2

RD22, ADH, RD29a/bP5CS,BADH

Na +

Na +

ABI2

Ca 2+

SOS3SOS2

Osmolytes(Proline, betaine)?

K +

HKT1Na

Receptor

Modified from Cheong and Yun (2007) J. Plant Biol

betaine)

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Does GI regulate general stress pathway ?

Page 12: GIGANTEA-mediated salt stress sigggpnaling in plantelearning.kocw.net/.../wcu/2013/KyungSang/KimWoeyeon1/1.pdf · 2013-07-24 · GI mutant exhibits increased salt tolerance WT gi-1

Salt stress tolerance in Plants

[Ca 2+]ext

High [Na +]

SOS1

H +Sodium efflux

[Ca 2+]int

PM

Ion SOS3 SOS2

SOS1

Na +

Na +

[ ]int

homeostasisSalt stress signaling

H + H +

Ca 2+

V-ATPasePPase

MYC/MYB/AREB/DREB2A

NU

Compartmentation

NHX

VacuoleH +

N + 2

RD22, ADH, RD29a/bP5CS,BADH

Na +

Na +

ABI2

Ca 2+

SOS3SOS2

Osmolytes(Proline, betaine)?

K +

HKT1Na

Receptor

Modified from Cheong and Yun (2007) J. Plant Biol

betaine)

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SOS1 i l b N /H hSOS1 is a plasma membrane Na+/H+ exchanger

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GI mutant plasma membrane vesicles exhibits high Na+/H+ antiporter activityNa /H antiporter activity

20gi-1

15

n-1

mg-

1 gi-1Col-0sos1-1

+NaCl

5

10

/Fm

axm

i

0

5∆F/

0 50 100 150 200 250NaCl (mM)

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GI influences SOS1 stability

SOS1WB:

SOS1 Anti-SOS1

CBBCBB

SOS1Transcript

TUB

p

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GI mutants exhibits increased salt tolerance

ore

ter

Bef

o

mM

Aft

150

mM

0

1

Page 17: GIGANTEA-mediated salt stress sigggpnaling in plantelearning.kocw.net/.../wcu/2013/KyungSang/KimWoeyeon1/1.pdf · 2013-07-24 · GI mutant exhibits increased salt tolerance WT gi-1

GIGANTEA controls the circadian clock and time of flowering through protein stabilizationtime of flowering through protein stabilization

Modified from Deng (2012) Trends in Plant Science

Page 18: GIGANTEA-mediated salt stress sigggpnaling in plantelearning.kocw.net/.../wcu/2013/KyungSang/KimWoeyeon1/1.pdf · 2013-07-24 · GI mutant exhibits increased salt tolerance WT gi-1

Sites for GI to regulate salt stress ?

Hi h [N +]High [Na +]

SOS1

Na +

H +

GI?Ca 2+ SOS3

SOS2GI?GI?

GI?

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GI interaction with SOSs proteins

DIC YFP MERGE

GI-VN +VC-SOS2

GI-VN +VC-SOS2

GI-VN +VC

VN +VC SOS2

C I i it ti

VC-SOS2

Bimolecular FluorescenceCo-Immunoprecipitation assay Bimolecular Fluorescence Complementation (BiFC)

Page 20: GIGANTEA-mediated salt stress sigggpnaling in plantelearning.kocw.net/.../wcu/2013/KyungSang/KimWoeyeon1/1.pdf · 2013-07-24 · GI mutant exhibits increased salt tolerance WT gi-1

GI interacts SOS2 directly in vitro

Input S2 S3

35S- GISOS1

H +

GST

35S-

GI

Input

GST

-SO

S

GST

-SO

S

SOS3SOS2

GI?GI?Na +

35S- GI High [Na +]

Ca 2+

CBB

GST- SOS2

GST- SOS3H +

GSTSOS3

SOS1

Na +

High [N +]

Ca 2+SOS2

GI[Na +]

Page 21: GIGANTEA-mediated salt stress sigggpnaling in plantelearning.kocw.net/.../wcu/2013/KyungSang/KimWoeyeon1/1.pdf · 2013-07-24 · GI mutant exhibits increased salt tolerance WT gi-1

SOS1 is phosphorylated by SOS2 upon salt stress

SOS1:His

Quintero et al. (2002) PNAS 99: 9061-9066

Page 22: GIGANTEA-mediated salt stress sigggpnaling in plantelearning.kocw.net/.../wcu/2013/KyungSang/KimWoeyeon1/1.pdf · 2013-07-24 · GI mutant exhibits increased salt tolerance WT gi-1

GI inhibits SOS2 kinase activity

12)

68

1012

sity

(SO

S1)

246

ativ

e in

tens

0Rel

a

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gi-1 salt tolerance and SOS1 stability is SOS2 dependentdependent

ore

Bef

oM

Afte

r m

M

0 m

M15

0 m

Page 24: GIGANTEA-mediated salt stress sigggpnaling in plantelearning.kocw.net/.../wcu/2013/KyungSang/KimWoeyeon1/1.pdf · 2013-07-24 · GI mutant exhibits increased salt tolerance WT gi-1

Sites for GI to regulate salt stress ?

Hi h [N +]High [Na +]

SOS1

Na +

H +

GI?Ca 2+ SOS3

SOS2

GI?

SOS2

GI

Page 25: GIGANTEA-mediated salt stress sigggpnaling in plantelearning.kocw.net/.../wcu/2013/KyungSang/KimWoeyeon1/1.pdf · 2013-07-24 · GI mutant exhibits increased salt tolerance WT gi-1

GI/SOS2 interaction is abolished by SOS3 and Salt

Hi h [N +]High [Na +]SOS1

SOS3

GISOS2SOS2

GI SOS3

100 mM NaCl / 24 h-NaCl

Page 26: GIGANTEA-mediated salt stress sigggpnaling in plantelearning.kocw.net/.../wcu/2013/KyungSang/KimWoeyeon1/1.pdf · 2013-07-24 · GI mutant exhibits increased salt tolerance WT gi-1

Working Model

High [Na +]

- SALT +SALTSalt tolerance g [ ]

SOS1

Na +

H +

SOS1 P

Ca 2+

SOS3 SOS2SOS3

GISOS3

SOS2

Inhibition

SOS2SOS3

GI GI


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