This document discusses plant tolerance to climate change and abiotic stresses like drought and soil salinity. It notes that climate change caused by human activities is causing more extreme weather events like droughts that threaten global agriculture and food security. Plants have developed tolerance mechanisms to cope with stresses, but their sedentary nature makes adaptation difficult. The document reviews research on stress response pathways and genes that confer tolerance to drought and salt when overexpressed. It argues that improving stress tolerance in crops through transgenic and molecular breeding approaches will be crucial to ensuring food security in a changing climate.

1. Plant Tolerance Versus Climate Change
Zhang WenSheng
Center for agriculture resource research, Institute of genetics
and development biology, Chinese Academy of Science
2011.11.07

2. Humans activities → Climate change & global warming → Agricultural production & food security
→
• Although the earth’s climate has been slowly evolving over millions of years,
rapid changes have occurred in recent times due to the activities of humans. It is
now known that climate change and the continuing atmospheric CO2 rise will
have increasingly profound effects on abiotic stress, plant growth and food
security. Among the abiotic stress, drought and soil salinity are two major
factors worldwide.

3. Climate change and drought
March, 2010, Yunnan, China January 10, 2011, Source: Division of Climate Impoact Assessment/NCC/CMA
In spring of 2010, severe drought hit China's south-west region and in some places it is
the worst drought for a century. The drought impacted about 4.3million hectares of
farmland and more than 51million people. Direct economic damage had reached more
than 370 million Yuan.
The 2010–2011 China drought impacted eight provinces in the northern part of China. It
was the worst drought to hit our country in 60 years, and it affected most of wheat-
producing regions in China.

4. Climate change: Drought may threaten much of globe within decades
From NCAR

5. Climate change and the increase of soil salinity
• Another problem related to climate changes and global warming is the increase of
soil salinity. Sea level rise, the increasing frequency of dry periods in many
regions of the world result in the consecutive occurrence of salinity on cultivated
land. It was estimated that 20% of all cultivated land and 50% of irrigated land are
affected by salt, greatly reducing the yield of crops.
Climate change enhances the importance and urgency of
plant tolerance research and tolerant crops breeding

6. Immobile lifestyle of plants
Tolerance & Resistance OR Death

7. Plants are exposed to a variety of abiotic stresses.
These stresses often occur in combination
Vickers et al. 2009, Nature

8. Generic pathway for plant response to stress
Huang et al. 2011, Mol Biol Rep

9. Transcriptional regulatory networks of abiotic stress signals and gene expression.
Shinozaki K , Yamaguchi-Shinozaki K J. Exp. Bot.
2006;58:221-227
© The Author [2006]. Published by Oxford University Press [on behalf of the Society for
Experimental Biology]. All rights reserved. For Permissions, please e-mail:
journals.permissions@oxfordjournals.org

10. Expression profiles of 7000 Arabidopsis genes under drought, cold
and high-salinity stresses using full-length cDNA microarray
Up regulated Down regulated
Motoaki Seki et al.2002, The Plant Journal

11. List of genes involved in different functional groups upregulated or
downregulated by drought, cold or high-salinity stress
Motoaki Seki et al. 2002, The Plant Journal

12. The feasibility of modification of a single trait significantly
improved the salinity tolerance of crop plant
Apse et al. 1999, Science Zhang & Blumwald, 2001, Nature
Salt treatment of wild-type plants and plants overexpressing AtNHX1 in the presence of 200 mM NaCl.

13. Zhang zhengbin’s research team
Cloning and function analysis of drought or salt tolerance related genes in wheat:
TaWRKY, TaAQP, TaCer, TaNADP-ME
Wild type 35S::TaWRKY2 35S::WRKY19
CK
150mM NaCl
Transgenic of such transcription factors may be a good strategy
for increasing plant tolerance

14. Genes used in the transformation of plants where authors claimed enhancement of salt tolerance, 1993-2011

15. The complexity of the natural The complexity of the
stressful environment + tolerance mechanisms
To make plants to rapidly acclimate the changing climate, and
. achieve genetic increases in yield under abiotic stresses is a
difficult challenge.
• Comprehensive studies on key genes, quantitative trait loci and molecular
networks that mediate plant responses to drought, salinity and other abiotic
stresses are necessary to overcome this global challenge. The rapid expansion
in knowledge on genomics and proteomics will accelerate the transgenic and
molecular breeding approaches.