biomassasia07fujitak.ppt - iTAP

deadstructureBiotechnology

Dec 14, 2012 (4 years and 6 months ago)

223 views

*Yasunari Fujita (JIRCAS, JAPAN)

Kazuko Yamaguchi
-
Shinozaki (JIRCAS/Univ. Tokyo, JAPAN)

Kazuo Shinozaki (RIKEN, JAPAN)

4th Biomass
-
Asia Workshop Nov. 21, 2007

Improving drought and salt stress tolerance


in plants by gene transfer


Explosive increase

of population

In developing

countries

Environmental degradation and

climatic change around the world

Progress in

genetic engineering

Development of crop plants

tolerant to environmental

stresses such as drought,

salt loading and freezing

Drought

environmental

stress

Plant response to environmental stresses

Temperature

stress

Plant Cell

High salinity

Signal Perception

Signal Transduction

Gene Expression

Stress Response

and Tolerance

Strategies to engineer environmental stress tolerance


in plants

Promoters

control gene expression under

environmental stress conditions

Transgenic techniques

for various crops

to introduce useful genes

Promoter

Gene

Promoter

Gene

Genes

function in tolerance

to environmental stresses

Arabidopsis thaliana

as a model plant

Good for genetic analysis (2n).

Small plants easily grown.

Short life cycle (6
-
8 weeks).


Smallest genome in plant kingdom

(1.2 X 10
8

bp, 5 chromosomes).

Gene number is about 26,000.

Genome sequence was determined

in 2000.


Arabidopsis resource centers

supply mutants and DNA libraries.


Efficient transformation for

functional analysis of genes.

Functions of water
-
stress
-
inducible gene products

Water channel

protein

Detxification enzymes

Protection factors of

Macromolecules

(LEA protein)

Detoxication

enzyme

ABA biosynthetic

enzyme

Transcription factors

(MYB, MYC, DREB, AREB)

Protein kinases

(CDPK, MAPK)

Phospholipid metabolism

(PLC, PIP5K)

Water stress

Key enzymes for

Osmolyte biosynthesis

(proline, sugar)

Environmental stress tolerance

Environmental Stress

Tolerance

gene

expression

Overexpression of

DREB1A

DREB1A
gene regulates a lot of target genes

to enhance tolerance to environmental stresses

Expression of more than 40 genes

Tolerance

gene

expression

Tolerance

gene

expression


Enhanced stress tolerance

Drought and High salinity

Signal Perception

DREB1A

Tolerance

gene

expression

Enhanced expression of more than 40 genes

Tolerance

gene

expression

Tolerance

gene

expression

DREB1A

Signal Perception

Combinations of promoters and transcription factors



Constitutive promoter (35S)


DREB1A

DREB1A
gene

Constitutive promoter

The constitutive promoter leads



to generate DREB1A products

all the time



Stress
-
inducible promoter (RD29A)


DREB1A

DREB1A

gene

Stress
-
inducible promoter

The stress
-
inducible promoter leads


to generate DREB1A products

only under stress conditions

drought

high salinity

76.7%

65.0%

16.7%

42.8%

0.0%

13.8%

Transgenic
Arabidopsis
plants overexpressing DREB1 plants

display enhanced tolerance to dorught and salt stresses

No treatment

Stress
-
inducible

promoter (RD29A)



DREB1

Constitutive

promoter (35S)



DREB1

Wild type

Stress
-
inducible promoter is useful to generate


DREB1A products without affecting plant growth

Negative effect


on plat growth

Non
-
negative effect

on plant growth

stress condition

Normal growth condition

ON

OFF

ON

ON

Normal growth condition

stress condition

DREB1A
gene

Constitutive promoter

DREB1A

gene

Stress
-
inducible promoter

Engineering environmental stress tolerance


Model plants

Arabidopsis

Developing technologies

Wheat

Rice

Agriculturally important crops

Engineering for stress tolerance in crops

Maize

Sugarcane

Legumes

The DREB1A transgenic rice plants display
enhanced tolerance to drought stress

Wild type

DREB1A transgenic rice plants

Drought stress test:
Watering was withheld for 9 days, then
rewatering for 13days, before the photograph was taken.

Wild

Type

Transgenic plants

The DREB1A transgenic rice plants display
enhanced tolerance to salt stress

Salt stress test: Treated with 250mM NaCl for 3 days

CGIAR

rice

Arabidopsis

rice

Indica rice

maize

wheat

Collaboration for


development of stress

tolerant crops

JIRCAS

Biotechnology


Laboratory

Public Research

Institute

NIAS

Lotus Japonicus

(a model legume
)

NIVTS


cruciferous cropper

and vegetables

groundnut

pigeonpea

cassava

Central Res. Lab.

Hitachi, Ltd
.

petunia

Oji Paper
Co., Ltd.

Forestry Res. Inst.

eucalypt

Kaisui Chemical

Industry Co., Ltd.

turf

Company Institute

The University Tokyo

RD29A:DREB1A



Drought stress tolerance of

the transgenic petunia

dehydrated

for
14
摡ds

wt

Yoshiba et al. unpublished

Drought stress tolerance of the transgenic wheat

RD29A:DREB1A

wt

RD29A:DREB1A

wt

Pellegrineschi et al. genome 2004



Laboratory test

Improving stress tolerance by gene transfer

Exploring appropriate


stress
-
tolerance gene

Exploring appropriate


promoters

Select best
combination for
sugarcane

Stress
-
tolerance gene

promoter

Making transgenic sugarcane

Drought and salt


stress

Improving stress tolerance by
gene transfer

Field test to evaluate

stress tolerance and yield

Useful transcription factors to improve


stress tolerance

Wounding

Pathogen infection

Drought, Salinity

High temperature

Low temperature

Stress tolerance

Expression of stress
-
responsive genes

Transcription

factors

cis
-

elements