DEVELOPMENT OF DROUGHT-RESILIENT SOYBEAN, A DEEP INSIGHT INTO THE POTENTIAL OF MOLECULAR RESEARCH AND BREEDING TOOLS

Abiotic stresses continuously threaten agricultural crop growth and yield and add risk to food security. Drought stress has significantly reduced the growth and yield of soybean. Soybean is an important crop that offers several nutritional benefits to humans as well as livestock. Breeding of soybean resilient to drought stress is one of the main objectives of soybean breeders to sustain their growth in a water-deficit environment. Genomic regions play a key role in regulating drought tolerance in soybean. Several molecular research and breeding techniques have been used to explore the drought tolerance mechanism in soybean; however, the complexity of the drought tolerance mechanism hindered the large-scale use of breeding tools. Quantitative trait loci (QTL)mapping, genome-wide-association-studies (GWAS), transcriptomes, transcription factors (TFs) analysis, transgenic breeding, and clustered regularly interspaced short palindromic repeats (CRISPR) are being used to identify and transfer the genes regulatingdrought tolerance in soybean. A lot of QTLs have been used in QTL pyramiding to improve drought tolerance in soybean. GWAS has successfully enhanced the genetic improvement of soybean in response to drought stress. It is important to decipher the genetic control of drought tolerance by recognizing the genes expressed under drought stress using transcriptome and TFs analysis and exploiting these genes via genetic engineering and CRISPR/Cas9.The development of drought-tolerant soybean genotypes will sustain growth on water-deficit soils and will serve as a reference point for adopting these strategies in other crops. This review will serve as a rich source of information for research breeding that intends to enhance drought tolerance in soybean.