Morphological, physiological and biochemical insights into heat stress response in mungbean ( <i>Vigna radiata</i> (L.) Wilczek)

Abstract Mungbean ( Vigna radiata ) is a warm‐season legume crop and plays a crucial role in food and nutritional security in South and Southeast Asia. Being a legume crop, it also plays a role in ecosystem sustainability. However, crop cultivation is facing an imminent threat amid the recent rise in global temperature. The optimum temperature range for mungbean cultivation is 28–35°C, although some genotypes can grow well even up to 40°C of atmospheric temperature. Therefore, in this study, 1515 mungbean accessions were initially screened for heat‐responsive morphological and physiological traits to identify superior genotypes. From this preliminary screening, 75 diverse accessions were selected for a more comprehensive evaluation of heat‐responsive traits. Subsequently, 32 promising genotypes were chosen for an in‐depth analysis of enzymatic and nonenzymatic antioxidant activities under both heat‐stressed and non‐stressed conditions. Certain genotypes, namely IC76475, IC418452 and IC489062, were superior for multiple heat stress‐responsive traits. The phenotypic expression of these genotypes was further validated under controlled environmental conditions. Their heat stress tolerance was confirmed through RT‐PCR analysis of key candidate genes ( GmAKT2 , Cu / ZnSOD , APX1 and CAT1 ). The findings from this study will aid in developing mungbean cultivars with enhanced tolerance to heat stress.