Genome-Wide SNPs Identification and Determination of Proteins Associated with Stress Response in Sorghum (Sorghum bicolor L. Monech) Accessions

Currentefforts in sorghum breeding programs are exploiting genotyping-by-sequencing(GBS) data to provide full-genome scans for desired traits. The aim of thisstudy was to utilize GBS approach for the identification of genomic regionsassociated with stress response in sorghum (Sorghumbicolor L. Monech)accessions. DNA samples of twenty sorghum accessions, having different responseto drought, were used to prepare GBS libraries for sequencing. SNPs were calledusing the TASSELGBS pipeline and the tags that present at least 10 times in thedataset were considered and aligned to the reference genome of Sorghum bicolor. Theidentified SNPs were all compared with the published sorghum transcript relatedto stress response gene activity. Overall; 94.40% tags were aligned and 69,736 putative SNPs positionswere identified. Blast search revealed homology to annotated heat anddrought–tolerance associated genes which code for ATPases, Peroxidase,Hydrophobic protein LTI6A, Aquaporin SIP2-1, Aconitate hydratase andphosphatidylinositol-4-phosphate-5-kinase. The phylogeny of the 20 accessionswas constructed using the generated SNPs data. Phylogenetic analysis datashowed that the phenotypically tolerant line (El9) makes a separate cluster and the same forthe accessions HSD8653 and HSD5612 near to the cluster that includes most accessions with known post-flowering droughttolerance (HSD7410, HDS10033, HSD8552, GESHEISH and HSD8849).Post-flowering drought sensitive accessions (Tabat, Wadahmed, HSD6468 andHSD6478) formed a separate cluster while the sensitive accession HSD9959 andthe tolerant accessions HSD8511 and HSD9566 were distributed between the twoclusters. Thus, cluster analysis confirmed the variation among accessions inpost-flowering drought tolerance. With further validation, these markers may beused for marker assisted selection for breeding new sorghum genotypes withstress adaptation.