Abstract
The biosynthesis of camalexin, a major phytoalexin in Arabidopsis, is induced upon infection of a variety of pathogens, and abiotic stresses such as AgNO3 treatment and UV-B irradiation stimulate the biosynthesis as well. Recent studies have almost elucidated the entire pathway of camalexin biosynthesis pathway including several cytochromes P450. The expression levels of such biosynthetic genes have been demonstrated to be greatly enhanced under those inducing conditions. However, possible mechanisms underlying the induction of camalexin biosynthesis remain elusive.
Here we report identification and characterization of transcriotion factors involved in the induction of camalexin biosynthesis. One of T-DNA insertion events within transcrioption factor genes resulted in a significant reduction of the camalexin accumulation levels. We discuss possible regulation mechanisms of the camalexin biosynthesis involving the induction of this transctiption factor gene in terms of transcriptome analyses.
