Determination of amylose content and expression analysis of the Granular-Bound Starch Synthase I (GBSS1) gene in rice grains

Abstract

The study determined amylose content and expression level of GBSS I gene in rice grain. A total of eighteen (18) rice (Oryza sativa L) cultivars of Indica varieties were collected from the National Rice Research Institute (NRRI) Cuttack and screened for their percentage amylose contents. Three cultivars namely Bindli, Naveen and Pooja which had contrasting characters in percentage amylose were then planted and used for the expression analysis. In the first stage of grain filling Bindli had 0.27 fold expression while Pooja and Naveen had 1.72 and 1.44 respectively. There was dramatic increase in the expression levels of the gene in the middle stage of grain filling in all the three cultivars with relative folds of 10.97, 42.71 and 27.34 recorded in Bindli, Pooja and Naveen respectively. However, at the last stage of grain filling, GBSS1 expression was low compared to the second stage with expression folds of 7.12, 7.55 and 1.67 in Bindli, Pooja and Naveen cultivars respectively. On the whole, Bindli cultivar showed lowest expression of the gene (GBSS1) when compared to Pooja and Naveen.

Key words: rice gene, amylose, expression analysis, GBSS1