Microarray analysis reveals selenium down-regulates glucosinolate biosynthesis in Arabidopsis shoots

Glucosinolates (GS) are important plant secondary metabolites present in several plant species, including Arabidopsis thaliana. While genotypic and environmental regulations of GS have been reported, few studies present data on their regulation at the molecular level. Therefore, the objective of this study was to explore differential expression of genes associated with GS in Arabidopsis in response to selenium (Se), shown previously to impact GS accumulations in Brassica species. Arabidopsis was grown under 0.0 or 10.0 μmol Na₂SeO₄ in solution culture media. Shoot tissue samples were collected before anthesis for analytical assessment of GSs and genetic expression analysis of biosynthesis. Microarray analysis was performed using Arabidopsis oligo nucleotide chips containing more than 31,000 genes. Biosynthesis pathway analysis using AraCyc revealed that GS biosynthesis was invoked by the differentially expressed genes in this study. Involvement of the same gene in more than one biosynthesis pathway indicated that the same enzyme may be involved in multiple biosynthesis pathways of GS. These findings in Arabidopsis may be useful for modifying GS levels in agriculturally important plant species.