To determine the role of IDD family gene IDD4 in Arabidopsis thaliana in resistance against fungal pathogen Botrytis cinerea infection,the disease indices of over-expressing lines IDD4-OE,knock-out mutant idd4 and wild type(WT)plants were determined after inoculation with the pathogen,leaf cell death and accumulation of H2O2 were measured with tissue staining,and the expression level of Be.ACTIN gene which encodes actin of pathogen was analyzed by real-time quantitative RT-PCR(qRT-PCR).The disease indices and Bc.ACTIN expression in leaves of IDD4-OE were determined after ap-plying 0.1 mmol/L of exogenous salicylic acid(SA).The results showed that IDD4-OE plant was sus-ceptible and idd4 plant was resistant to this pathogen comparing with wild type.The cell death at patho-gen infection site in IDD4-OE plants was more severe than that in idd4 plants.Staining results showed that H2O2 was accumulated in the infection site four hours post inoculation with this pathogen.The Bc.ACTIN was expressed at higher levels in IDD4-OE than in idd4 plants,indicating that B.cinerea repro-duced at a faster rate in IDD4-OE.With SA pretreatment,the disease index and Bc.ACTINexpression in IDD4-OE plants were not significantly different from those of WT plants upon B.cinerea attack,suggest-ing that SA could increase the resistance of susceptible plants to the level of WT plants.The results indi-cated that IDD4 was acting as a negative regulator of SA-mediated resistance to B.cinerea in A.thaliana.
维普
万方数据