A critical review on the improvement of drought stress tolerance in rice (Oryza sativa L.)

Abstract
Abiotic stresses are the primary threat to crop production across the globe. Drought stress is primary abiotic stress which is considerably limiting the global rice production and putting the food security at higher risks. Drought tolerance (DT) is a multigene trait which is influenced by various stages of development in rice plant. Tolerance as well as susceptibility of rice to drought stress is carried out by different drought-response genes and other components of stress. Plant researchers have used various methods such as, genetic manipulation and marker-assisted techniques for development of new rice cultivars with improved tolerance to drought stress. The aims of this review are to present recent advancements and illustrate current approaches to breed a robust drought-resistant rice genotypes by using classical breeding and advanced molecular techniques. We also shed light on all available information regarding the role of significant hormones in DT, QTL for drought-related traits, QTL for rice yield, global strategies for the improvement of DT in rice, DT genes, and selection supported by markers.