Impact of heat stress on physiological characteristics and expression of heat shock proteins (HSPs) in groundnut (Arachis hypogaea L.)

The current climate change has a profound impact on agricultural production. Despite the unanimous efforts of several nations to prevent further increase in global temperatures, developing adaptive strategies by imparting heat tolerance in crop plants is essential to ensure global food security. This study demonstrates the impact of heat stress on the morphological, physiological and biochemical properties of different groundnut genotypes derived from a recombinant inbred line (RIL) population (JL 24 × 55–437). The plants were grown in controlled conditions and a high-temperature stress of 45 °C was gradually imposed by placing the plants in an environmental chamber during peak reproductive stage [25 days after sowing (DAS) to 60 DAS]. Heat tolerant genotypes had better biochemical machinery to withstand the heat stress-induced oxidative burst with higher activity of catalase and peroxidase. Also, the tolerant genotypes had lesser membrane damage as indicated by lower malondialdehyde levels. Greater expression of heat shock proteins (HSP17) transcripts alongside elevated levels of both enzymatic and non-enzymatic antioxidant activity was observed when exposed to high temperature, indicating their potential association with heat stress tolerance in groundnut.