Structural Analysis of a Gene Cluster Encoding DFR-like Proteins from Rice Chromosome 4

LEI Hai-Yan, ZHOU Bo, ZHANG Yu, HONG Guo-Fan*, HAN Bin

( National Center for Gene Research, Shanghai Institutes for Biological Sciences, the Chinese Academy of Sciences, Shanghai 200233, China)

Abstract Sequencing analysis of the 323 kb contig of rice chromosome 4 identified a gene cluster encoding 7 dihydroflavonol-4-reductase (DFR)-like proteins within a 56 kb region. The 7 DFR-like genes were found to be arranged in a tandem array, and all of them comprised 6 exons and 5 introns. Analysis of the predicted amino acid sequences demonstrated that these 7 proteins shared strong similarities with DFR and other enzymes of the phenylpropanoid biosynthesis pathway. RT-PCR revealed the expression pattern of the 7 genes was different in various rice tissues. The structural and functional features of these 7 DFR-like genes and their evolutionary implications are discussed.