Abiotic stress responses in plants - present and future

Drought, cold, high-salinity and heat are major abiotic stresses that severely reduce the yield of food crops worldwide. Traditional plant breeding approaches to improve abiotic stress tolerance of crops had limited success due to multigenic nature of stress tolerance. In the last decade molecular techniques have been used to understand the mechanisms by which plants perceive environmental signals and further their transmission to cellular machinery to activate adaptive responses. This knowledge is critical for the development of rational breeding and transgenic strategies to impart stress tolerance in crops. Studies on physiological and molecular mechanisms of abiotic stress tolerance have led to characterisation of a number of genes associated with stress adaptation. Techniques like microarrays have proven to be invaluable in generating a list of stress related genes. Some of these genes arc specific for a particular stress while others are shared between various stresses. Interestingly, a number of genes are shared in abiotic and biotic stress responses.