Comprehensive RNA-seq Analysis Revealed Molecular Pathways and Genes
Associated with Drought Tolerance in Wild Soybean (Glycine soja Sieb. &
Zucc.)
Abstract
Drought stress at germination stage is an important environmental stress
limiting crop yield. Hence, our study investigated comparative root
transcriptome profiles of four contrasting soybean genotypes viz.,
drought-tolerant (PI342618B/DTP & A214/DTL) and drought-sensitive
(NN86-4/DSP & A195/DSL) under drought stress using RNA-Seq approach.
Total of 4850 and 6272 differentially expressed genes (DEGs) were
identified in tolerant (DTP & DTL) and sensitive (DSP & DSL)
genotypes, respectively. Principle component analysis (PCA) and
correlation analysis revealed higher correlation of DTP with DTL. Both
gene ontology (GO) and MapMan analyses showed drought response was
enriched in the DEGs associated with water and auxin transport, cell
wall/membrane, antioxidant activity, catalytic activity, secondary
metabolism, signaling and transcription factor (TF) activities. Out of
981 DEGs screened from above terms, only 547 showed consistent opposite
expression between contrasting genotypes. Twenty-eight DEGs of 547 were
located on Chr.08 rich in QTLs and “Hotspot regions” associated with
drought stress, and eight of them showed non-synonymous SNP
polymorphism. Hence, ten genes (including above eight genes plus two hub
genes) were predicated as possible candidates regulating drought
tolerance, which needs further functional validation. Overall, the
transcriptome profiling provided in-depth understanding about the
genetic mechanism and candidate genes underlying drought tolerance in
soybean.