Novel allelic variation in the Phospholipase-D-alpha1 gene (OsPLDα1) of wild Oryza species implies to its low expression in rice bran

Rice bran, a by-product after milling, is a rich source of phytonutrients like oryzanols, tocopherols,tocotrienols, phytosterols, and dietary fibers. Moreover, exceptional properties of the rice bran oilmake it unparalleled to other vegetable oils. However, a lipolytic enzyme Phospholipase D alpha1(OsPLDα1) causes rancidity and ‘stale flavor’ in the oil, and thus limits the rice bran usage for humanconsumption. To improve the rice bran quality, sequence based allele mining at OsPLDα1 locus (3.6Kb) was performed across 48 accessions representing 11 wild Oryza species, 8 accessions of Africancultivated rice, and 7 Oryza sativa cultivars. From comparative sequence analysis, 216 SNPs and 30InDels were detected at the OsPLDα1 locus. Phylogenetic analysis revealed 20 OsPLDα1 cDNA variantswhich further translated into 12 protein variants. The O. officinalis protein variant, when comparedto Nipponbare, showed maximum variability comprising 22 amino acid substitutions and absenceof two peptide