GmPARPs differentially regulate the drought and heat stress tolerance in soybean

Soybean is a valuable crop that provides protein and oil. The soybean yield and quality are affected by abiotic stresses viz. drought and heat stress. The process of poly(ADP-ribosyl)ation is an essential component of crucial cellular processes, including abiotic stress tolerance. This study is an attempt to unravel the function of Glycine max poly(ADP-ribose) polymerases ( GmPARPs ) using Agrobacterium -mediated transformation in soybean. The present study has identified and characterized the GmPARPs gene in soybean using bioinformatic and molecular analyses. Quantitative real-time PCR (qRT-PCR) results showed the differential expression of GmPARPs under drought and heat stress conditions. Further, to elucidate the function of the GmPARPs in drought and heat stress, soybean GmPARPs-RNAi transgenic lines were raised which were confirmed by molecular analyses. Various physiological traits such as Fv/Fm ratio, H 2 O 2 production, and proline and chlorophyll content demonstrated the tolerance of GmPARPs-RNAi lines under drought and heat stress conditions. Besides, the role of stress-associated genes, Allene oxide synthase and Phenylalanine ammonia-lyase were studied to dissect the pathways involved in conferring drought and heat tolerance in GmPARPs-RNAi lines, which were consistent with the previous studies. Our study indicated that the downregulation of the GmPARP1 efficiently improves drought and heat tolerance in soybean. However, GmPARP2 knockdown could only protect soybean plants under drought stress. Thus, GmPARPs may also serve as an important target for the improvement of soybean cultivars and other crops.