Tissue-specific expression of the chalcone synthase multigene family in Phaseolus vulgaris: development of a RT-PCR method for the expression profiling of the chs isogenes

Chalcone synthase is a key metabolic control point in the biosynthesis of a large number of flavonoids and isoflavonoid metabolites. Chs genes in bean comprise a multigene family, of which certain individual members can be differentially induced with respect to kinetics and extent of accumulation. A RT-PCR technique, based on primers designed complementary to a common conserved region and divergent 3' sequences of the bean chs family, was developed to detect the expression of individual members of the chs family. The semi-quantitative technique is based on the amplification of short, overlapping sequences differing in size. The method was found to be sensitive, rapid, and capable of distinguishing among the individual chs members (chs 1, 4, 14, and 17). The tissue-specific expression of chs isogenes in bean seedlings, flowers and callus, as well as the effect of light on chs expression in etiolated tissue was documented.