Conclusion
The current study presents detailed information on drought tolerance at germination stage in four contrasting soybean genotypes viz., drought-tolerant (DTP & DTL) and drought-sensitive (DSP& DSL), and revealed the molecular mechanisms of drought tolerance. Our transcriptomic data revealed that tolerant genotype (DTP & DTL) is less affected compared to the sensitive genotypes by drought stress. Moreover, out of 981 DEGs screened for candidate gene prediction analysis, 547 exhibited significant opposite gene expression pattern between tolerant and sensitive genotypes, and 28 of them were located on the Chr.08 reported to possess most number of drought tolerant QTLs/“QTL Hotspots”. Eight of these 28 genes showed non-synonymous SNPs, and two were located within “Hotspot region” associated with drought tolerance on Chr.08. Hence, based on the gene annotation, PPI and sequencing analysis, ten genes including above eight genes plus two hub genes were predicated as most possible candidate genes regulating drought tolerance in soybean. Hence, these ten genes required functional validation before they can be used for breeding drought tolerance in soybean. Overall, our study provides valuable information to understand drought tolerance mechanism, and will greatly assists in cloning drought-tolerant genes for breeding improved soybean cultivars.