Diversity of glutelin acidic subunit polypeptides in rice cultivars collected from Northern Vietnam

Abstract

The diversity of glutelin acidic polypeptides in rice cultivars collected from Northern Vietnam was characterized via sodium dodecyl sulphatepolyacrylamide gel electrophoresis (SDS-PAGE) and isoelectric focusing (IEF) electrophoresis. Glutelin acidic subunits were separated into four bands by molecular mass, as a-1 (39 kDa), a-2 (38 kDa), a-3 (37.5 or 37 kDa) and a-4 (34 or 33 kDa). One hundred and eighty-five Vietnamese rice cultivars were divided into three types, based on differences in staining intensity and the molecular size of the a-3 and a-4 polypeptides derived from SDS-PAGE analysis. Wide variation was also observed in the isoelectric point (pI) staining intensity, in addition to the absence/ presence of pI bands detected via IEF analysis. A total of 16 pI bands, ranging from pI 6.30 to pI 7.52, were identified in the various local rice cultivars. The maximum and minimum of IEF bands detected were 14 and 10, respectively. The genetic variability index (H′) ranged from 0.280 to 0.820, which confirms that local rice cultivars from Northern Vietnam have diverse glutelin seed storage units.