Metabolic profiling studies towards identification of novel transcription factor genes involved in the camalexin biosynthesis in Arabidopsis

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 are also known to stimulate the biosynthesis. Recent studies have almost elucidated the camalexin biosynthetic pathway including several cytochromes P450 and nitrilases, and the expression levels of such biosynthetic genes have been demonstrated to be greatly induced under those inducing conditions. However, possible mechanisms underlying the induction of camalexin biosynthesis remain elusive
Here we report our metabolic profiling study for identification of transcriotion factors involved in the induction of camalexin biosynthesis. One of T-DNA insertion events within transcrioption factor genes was revealed to have reduced the camalexin accumulation levels under the induction treatment. We discuss possible regulation mechanisms of the camalexin biosynthesis involving the induction of this transctiption factor gene in terms of transcriptome analyses.