Key insights to develop drought-resilient soybean: A review

Soybean (Glycine max L.) is one of the most important legume crops that provide high protein contents compared to any other crop. Drought stress is one of the most devastating abiotic factors that pose severe threats to crop growth and production. Soybean growth and production are hindered by drought stress which is continuously declining yield and quality. Several studies have been conducted to unfold the genetic mechanism of drought tolerance in soybean, but to our knowledge, genetic control of drought-tolerant traits is not yet fully understood. The need for time is to make a fruitful effort to develop drought-tolerant soybean varieties that can ensure sustainability in terms of production and quality. Different soybean traits contribute to drought tolerance, and studies are being conducted to evaluate the soybean under water deficit conditions. Molecular techniques including genetic engineering, identifying quantitative trait loci (QTL), clustered regularly interspaced short palindromic repeats (CRISPR), and transcriptomes have been extensively used to develop drought-tolerant soybean cultivars. The CRISPR/Cas9 is one of the novel and most potent gene editing tools which is revolutionizing agriculture sector by targeted editing of the desired gene. Soybean offers an excellent opportunity to apply CRISPR/Cas9 because of its complex genetic network. Conventional techniques are being used to develop drought-tolerant soybean cultivars. There is still a need to integrate the available breeding tools to identify and transfer the potent genes contributing to drought tolerance. Conventional breeding methods like hybridization, backcrossing, and pedigree are suitable for breeding novel drought-tolerant cultivars. More studies are required to investigate the soybean response to drought stress at the morphological, biochemical, and molecular levels, allowing breeders to choose a proper way of improving drought tolerance. The current review provides a detailed overview of improving drought tolerance and will help conduct further research studies to develop drought-resilient soybean cultivars.