Overexpression of Bax inhibitor suppresses the fungal elicitor-induced cell death in rice (Oryza sativa L.) cells

Treatment of suspension-cultured cells of rice (Oryza sativa L.) with cell wall extract of rice blast fungus (Magnaporthe grisea ) elicits a rapid generation of H2O2, alkalinization of culture medium, and eventual cell death. To elucidate genes involved in these processes, we exploited SAGE (Serial Analysis of Gene Expression) technique for the molecular analysis of cell death in suspension-cultured cells treated with the elicitor. Among the downregulated genes in the elicitor-treated cells, a BI-1 gene coding for Bax inhibitor was identified. Transgenic rice cells overexpressing Arabidopsis BI-1 gene showed sustainable cell survival when challenged with M. grisea elicitor. Thus, the plant Bax inhibitor plays a functional role in regulating cell death in the rice cell culture system.