Isolation, characterization and expression analysis of novel water deficit stress-responsive DEEPER ROOTING 1 (DRO1) gene from drought-tolerant Erianthus arundinaceus

Sugarcane (Saccharum spp.) is an important food, fodder and energy crop in India. Its production and productivity are mainly constrained due to water deficit stress during different growth stages. Of the root system architecture traits, deep rooting helps plants to avoid drought-induced stress by foraging moisture from deeper layers of soil. Hence, in this study, a novel drought-responsive DEEPER ROOTING 1 (DRO1) gene cloned from drought-tolerant Erianthus arundinaceus was characterized. The open reading frame of this gene is 765 bp that encodes for a single polypeptide of 254 amino acids. In silico analysis of DRO1 protein using bioinformatics tools revealed its size of 28.91 kDa with theoretical pI 5.39, instability index 67.57, aliphatic index 69.92 and GRAVY of -0.86. Subcellular localization by LocTree3 tool suggested that DRO1 protein expression is localized in the nucleus. The phylogenetic tree exhibited that DRO1 from Erianthus arundinaceus is closely associated with that of Sorghum bicolor and Triticum aestivum. Protein interaction network analysis showed DRO1 association with WOX11, which promotes the development of crown roots and ARL1 (Adventitious rootless1) required for adventitious root formation. Quantitative gene expression analysis indicated that the DRO1 gene is differentially upregulated in root tissue of E. arundinaceus and Saccharum spp. commercial hybrid under water deficit stress conditions. EaDRO1 gene can be a novel source for developing drought stress tolerant genotypes through genetic engineering approach.