Nucleotide Sequences of Three Chalcone Reductase Genes from Alfalfa

Abstract

An important reaction in the biosynthesis of many phytoalexins in leguminous plants is the formation of 4,2',4'trihydroxychalcone from 4-coumaroyl-COA and malonyl-COA, first demonstrated by Ayabe et al. (1988). They showed also that the two enzymes are induced coordinately after treatment of the cell cultures with elicitor-type molecules. Moreover, This reductase can play a fundamental role in planta in the balancing of the production of 5-deoxyflavonoids or 5-hydroxyflavonoids, the synthesis of which depends on the co-action of CHS and CHR or on CHS alone, respectively. Despite this pivotal role and except for the pioneering work already cited, the CHR has not been extensively studied, either at the enzymatic or gene expression levels.