Expression study of genes responsible for grain filling in rice through microarray analysis

Abstract

To identify the genes responsible for grain filling, we compared the transcription profilling of genes in superior (SS) and inferior (IS) spikelets in rice on 1, 7 and 13 days after flowering using a microarray system. Genes involved in carbohydrate metabolism were mainly analyzed and classified into 3 groups according to their expression patterns. Group1 gene expression decreased accompanying the spikelet development. It includes starch- and sucrose- synthases, and sugar transporters. Their expression in IS delayed than SS, which may delay the spikelet development in IS. Group2 gene expression increased accompanying the spikelet development. It contains branching enzymes, glutelins and prolamins. They expressed higher in SS than IS. It might bring better grain filling in SS. Group3 genes which expressed higher in IS than SS include alpha-amylases. They catalyze starch degradation and may cause poor grain filling in IS.