GWAS to delineating genomic regions contributing to heat stress tolerance at vegetative stage in mung bean

Mung bean is a vital grain legume crop valued for its high protein content, essential vitamins, and micronutrients. However, increasing occurrences of heat stress pose a significant challenge to its production. While substantial research has explored physiological and biochemical responses to heat stress, there remains a dearth of genomic resources identifying the genetic basis of heat stress tolerance in mung bean. This study employed a genome-wide association study to identify genomic regions and candidate genes associated with heat stress tolerance during the vegetative stage. A globally diverse panel of 396 genotypes was evaluated under optimal (in between 34 to 25 degree centigrate) and heat stress (above 45 degree centigrate) conditions, assessing six major morpho-physiological traits. Marker-trait association (MTA) analysis identified nine significant MTAs under optimal conditions and 12 under heat stress. Eleven putative candidate genes were identified, including those encoding phytochrome A-like proteins, leucine-rich repeat extension-like proteins, and calcium ATPases. These findings highlight key genomic regions and biological pathways involved in heat stress tolerance, providing valuable genomic resources for marker-assisted breeding to develop heat-resilient mung bean cultivars.