Abstract
Sulfur is an essential nutrient for growth of plants. Recently, a cis-acting element which responds to sulfur deficiency was identified in Arabidopsis (Maruyama-Nakashita et al. 2005). Our aim is to search transcription factors regulating sulfur assimilation.
Two public databases, ATTED (Arabidopsis thaliana trans-factor and cis-element prediction database; http://www.atted.bio.titech.ac.jp/) and AtGenExpress JPN (http://pfg.psc.riken.jp/AtGenExpress/index.html) were used to find transcription factors of which expression correlate with those of sulfur assimilation related genes and are induced under sulfur deficiency. Here, we investigated a Myb gene as a candidate. We over-expressed a full-length cDNA fragment of the gene in Arabidopsis suspension-cultured cell lines. Transcriptome analysis showed reduction of expression of a high affinity sulfate transporter gene. Furthermore, metabolite analyses using capillary electrophoresis (CE) and high performance liquid chromatography (HPLC) showed reduction of contents of sulfur-related metabolites. The results suggest that the Myb transcription factor down-regulates sulfur assimilation.
