Defense gene expression in elicitor-treated cell suspension cultures of french bean cv. Imuna.

Cell suspension cultures of bean (Phaseolus vulgaris) cv. Imuna accumulated isoflavonoid phytoalexins on exposure to elicitor from the phytopathogenic fungus Colletotrichum lindemuthianum (CL). This was preceeded by rapid increases in the activities of phenylalanine ammonia-lyase (PAL) and chalcone synthase (CHS). However, the patterns of expression of PAL and CHS genes differed from those observed in cultures of a previously studied bean cultivar. The relative levels of transcripts from individual members of the CHS multigene family differed significantly at 1.5 h compared to 22.5 h after elicitation. More strikingly, three PAL genes were expressed in cultivar Imuna in response to fungal elicitor, whereas two are expressed in elicitor-treated cell cultures of cultivar Canadian Wonder.