To elucidate the elicitor-mediated transcriptional activation in one of the chalcone synthase genes, PSCHS2 in pea, we investigated the putative cis-regulatory elements in the promoter sequence and trans-acting DNA binding proteins. The promoter up to -471 from the transcription start site of PSCHS2 gave considerable level of basal transcriptional activity. Nuclear extract from elicitortreated pea epicotyls formed DNA-protein complexes with three independent DNA fragments spanning from +83 to -484 of PSCHS2 with low mobility (LMC,low mobility complex) in the gel mobility shift assay. Since the LMC formation was blocked by the treatment of nuclear extract with alkaline phosphatase, the phosphorylation of some nuclear factor(s) assists LMC formation. These results indicate that the bindings of the putative positive nuclear factors to the multiple cisregulatory elements in PSCHS2 promoter region were enhanced by elicitortreatment that might result in transcriptional activation.