【目的】阐明在不同黄单胞病菌诱导的水稻过敏性细胞死亡(HCD)中的一氧化氮(NO)信号途径及其作用机制。【方法】比较分析了在水稻细胞-番茄斑点病菌(Xanthomonas campestris pv.vesicatoria,Xcv)不亲和互作、水稻-白叶枯病菌(X.oryzaepv.oryzae,Xoo)亲和互作中NO的发生以及NO对水稻防卫基因诱导表达的影响。【结果】Xcv不仅诱导了NO的迸发、NOS活性及其NO合成相关基因(nos和nr)的表达,而且诱导了防卫基因(苯丙氨酸解氨酶基因pal、过氧化物酶基因pox和谷胱苷肽转硫酶基因gst)的表达;Xoo不诱导NO的迸发,抑制了NOS的活性、NO合成相关基因和防卫基因的表达;NO清除剂PTIO和Xoo显著地抑制了Xcv对防卫基因表达的诱导作用。【结论】Xcv通过NO信号途径诱导了水稻防卫基因的表达和HCD;Xoo通过NO抑制或解毒机制抑制了由NO介导的防卫基因的表达及其HCD的发生。
【Objective】The project was conducted to elucidate a key role for nitric oxide (NO) played during rice-Xanthomonas spp interactions by triggering hypersensitive cell death (HCD) and inducing defense genes. 【Method】NO production and defense gene expression in rice suspension-cultured cells was compared after X. campestris pv. vesicatoria (Xcv) inoculations, a non-host bacterial pathogen and X. oryzae pv. oryzae (Xoo), the bacterial blight pathogen of rice. 【Result】 NO burst, activation of nitric oxide synthas...