Mechanism of Gene Expression of Two Arabidopsis Gluthatione S-transferase, AtGST1 and AtGST11, in Response to Aluminum (Al) Stress

Abstract

Gene expression of Al-induced Arabidopsis GST genes, AtGST1 and AtGST11, was analyzed to investigate the gene response mechanism to Al stress. Transgenic lines carrying pAtGST1::GUS or pAtGST11::GUS genes showed a time-dependent expression to a different degree in the root and/or leaf by Al stress. The pAtGST1::GUS gene was induced after a short treatment (maximum expression after 2 h), while the pAtGST11::GUS gene was induced by a longer Al treatment (approximately 8 h). Since the gene expression was observed in the leaf even when only the root was exposed to Al, a signaling system between the root and shoot was suggested in Al stress. Microscopic observations of Al-treated leaves suggested that the stress-specific signal(s) is transferred via veins. It was also suggested that the degree of Al toxicity in the root reflects the gene response of pAtGST11::GUS in the shoot via the deduced signaling system.