cDNA cloning and sequence analysis of the rice cinnamate-4-hydroxylase gene, a cytochrome P450-dependent monooxygenase involved in the general phenylpropanoid pathway

Plant cytochrome P450 monooxygenases (P450s) mediate a wide range of oxidative reactions involved in the biosynthesis of phenylpropanoids, terpenes, lipids, and alkaloids. We isolated a cDNA clone for cinnamate-4-hydroxylase (C4H) from a japonica type rice (Oryza sativa L. cv. llpumbyeo). This C4H has a deduced amino acid sequence that is 85% identical to that of Sorghum bicolor. Our phylogenetic analysis also showed that the OsC4HL gene is closely related to C4H from S. bicolor. A putative genomic DNA sequence corresponding to OsC4HL contained cis-elements (boxes P, A, L, and TCA motifs), AT-rich elements, and wound-response elements that control gene expression in its promoter region. OsC4HL expression was detected in all the tissue types, with the highest level being measured in the roots. It was also apparently up-regulated by wounding stress. These data suggest that the OsC4HL gene is C4H member in the CYP73 subfamily.