Agriculture Reference
In-Depth Information
Chapter 22
Improvement of Stress Tolerance in
Crops by Genetic Manipulation of ABA
Metabolism, Signaling, and Regulation
Hao Du and Lizhong Xiong
Abstract
Abiotic stresses such as extremes in water, temperature, and salinity are
major limiting factors for the productivity of most crops. The plant response and
adaptation to these stresses are controlled by numerous small-effect loci and regulated
by hundreds of genes controlling various developmental and physiological processes.
The elucidation of the abscisic acid (ABA) functional mechanisms in mediating the
response and adaptation to stresses as described in the previous chapters has provided
many opportunities for the development of new crop varieties with enhanced stress
resistance. In this chapter, we mainly focus on the recent studies of ABA-related
genes (involved in metabolism, signaling, and regulation) that have been well char-
acterized and are known to affect stress resistance and especially those genes which
have been engineered in crops for stress resistance improvement. Although there
is evidence that many ABA-related genes have a biologically significant effect in
improving stress resistance, a large gap remains to generate crops with significantly
improved stress resistance in the field. A significant challenge is to unveil the com-
plex mechanisms of stress resistance in crops by more intensive and integrative stud-
ies to find the key functional components involved in the ABA-mediated biological
processes as tools for engineering and breeding stress-resistant crops.
Keywords
Stress tolerance
·
Genetic manipulation
·
ABA-related genes
22.1 Introduction
Climate change, the distribution of contagious water, and soil salinization are
global problems relevant to all of the living organisms on the earth and are
caused mainly by the increasing world population. These extreme environmental
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