Transgenic Approaches for Abiotic Stress Tolerance in Plants

Abstract

Abiotic stresses such as drought, ooding or submergence, heat and cold spells, freezing and salinity are harmful factors which reduce growth and productivity of crops and are a serious threat to agriculture and environment. Understanding the mechanism(s) involved in the response of plants to abiotic stresses is the first step in development of stress tolerant crops. Transgenic plants that express/over-express genes regulating osmolytes, ion homeostasis, reactive oxygen species (ROS) scavenging, late embryogenesis abundant (LEA) and heat shock proteins, transcription factors and signal transduction showed improved tolerance to many abiotic stresses. Although, many genes associated with plant response(s) to abiotic stresses have been identified and used to generate stress tolerant plants, the success in producing commercially stress-tolerant crops is rather limited. Accurate and systematic phenotyping under conditions that mimic the natural field situation for a prolonged period is a major challenge limiting the success of abiotic stress tolerant transgenics. This chapter highlights the most significant achievements of the transgenic approach to improve tolerance to drought, salinity, chilling and heat stress and the limitations that hinder the commercialization of abiotic stress tolerant transgenic crops.