Phytoremediation and phytosensing of chemical contaminant, toluene: identification of the required target genes.

As an industrial chemical produced worldwide in high volumes, toluene is commonly detected in ambient air and water. It can combine with oxygen and form compounds that are harmful to humans. In recent years, phytoremediation has been increasingly applied to repair the environmental damage caused by pollutants. However, insufficient knowledge is available regarding the response of plants to toluene. To detect the potential genes in plants that are related to the sensing mechanism and metabolism of toluene, a microarray analysis has been conducted on Arabidopsis thaliana seedlings grown on toluene-containing media. Following the validation of data and the application of appropriate selection criteria, the results show a coordinated induction and suppression of 202 and 67 toluene-responsive genes, respectively. Within the functional class "metabolism", the genes encoding detoxification proteins represent the most strongly up-regulated group. These include genes encoding cytochrome P450s, glucosyl transferases, and transporters. Subsequently, the toluene-induced genes of Arabidopsis are analyzed in detail.