DROUGHT TOLERANCE IN MAJOR CROPS: PHYSIOLOGICAL TRAITS AND BREEDING STRATEGIES

Droughts are occurring more frequently and intensively due to climate change, posing a significant threat to crop cultivation and food security. This review examines the morphological traits, cellular adaptations, and breeding behaviours that enable major crops to endure drought. We highlight some of the most important characteristics: root growth, stomatal regulation, adaptation to water stress, resistance to oxidation, and the resistance of some plants to staying green. We discuss the mechanisms by which these characteristics are regulated by the hormone abscisic acid, by important genes such as DREB, NAC, and WRKY, protective proteins, and DNA modification. Other new breeding technologies, such as markerassisted and genome-based selection, CRISPR editing, rapid screening of multiple plants, and the use of beneficial microbes, have accelerated the deployment of these traits and demonstrated real benefits in laboratory and field experiments. Nevertheless, drought tolerance is a multi-gene process, with limited field testing across various locations and social and policy barriers remaining. We propose an integrated workflow that combines multiple data types, AI to select the most suitable plants, and farmer-led experiments to introduce novel varieties sooner. We indicate that unpopular crops such as millets may be suitable for climate-smart breeding.