Drought Tolerance Strategies in Plants: A Mechanistic Approach

Anthropogenic activities in the past and present eras have created global warming and consequently a storm of drought stress, affecting both plants and animals. Being sessile, plants are more vulnerable to drought stress and consequently reduce plant growth and yield. To mitigate the effects of drought stress on plants, it is very crucial to determine the plant response mechanisms against drought stress. Drought response mechanism includes morph-physiological, biochemical, cellular and molecular processes takes place in plants underlying drought stress. These processes include improvement in root system, leaf structure, osmotic adjustment, relative water content and stomata regulation. In addition, calcium and phytohormone (Abscisic acid, Jasmonic acid, Salicylic acid, Auxins, Gibberellins, Ethylene etc.) signaling pathways and scavenging of reactive oxygen species are the key mechanisms to cope with drought stress. Moreover, microorganisms such as bacteria and fungi also have an important role in drought tolerance enhancement. To further elucidate and improve drought tolerance in plants, quantitative trait loci, transgenic approach and application of exogenous substances (nitric oxide, 24-epibrassinoide, glycine betaine and proline) are very crucial. Hereby, the present study integrates various mechanisms of drought tolerance in plants.