摘要
超敏反应(hypersensitive response,HR)是植物抵御病原物的一种有效方式。植物类病变(lesion mim-ic)是一类能自发产生类似HR细胞坏死的突变体,在植物抗病机理研究中具有重要意义。对水稻类病变突变体spl5的抗病性研究发现,spl5增强了对白叶枯病菌4个菲律宾小种和10个中国小种的抗性,具有广谱抗病性。在spl5中活性氧显著积累,表现出HR的早期特征"氧迸发"现象,活性氧清除酶SOD,POD和CAT的酶活力也显著性变化,表明spl5中活性氧代谢的平衡失调可能是诱发HR原因之一。同时,RT-PCR分析发现1个水杨酸(EDS1)和2个茉莉酸(AOS2,LOX2)信号途径中的关键调控基因及其下游2个病程相关基因(PR1a,PR1b)在spl5中表达上调,推测spl5的突变可能激活了水杨酸与茉莉酸途径的信号转导,从而启动了植株的系统防御应答反应。
Hypersensitive response （HR） is an effective way of plants against pathogens. Lesion mimic mutants spontaneously exhibit HR-like cell death in absence of pathogens, and are of great significance in dissecting the mo- lecular mechanisms of disease resistance in plants. In this study, it was found that the resistance against 4 Philippine races and 10 Chinese races was significantly enhanced in the spl5 mutant, indicating that the spl5 mutant displays a broad-spectrum resistance to Xoo. Reactive oxygen species （ROS） were significantly accumulated in spl5 leaves, which is an early feature of HR with reactive oxygen burst, meanwhile, activities of ROS scavenging enzymes such as SOD, POD and CAT significantly changed in spl5, indicating that the imbalance of ROS metabolism might trigger HR occurrence in spl5. In addition, RT-PCR-based assay showed that transcriptional levels of EDS1, AOS2 and LOX2, key regulators in salicylic acid （SA） and jasmonic acid （JA） signaling pathways, respectively, and their down- stream pathogenesis-related genes such as PRla and PRlb were up-regulated in splS. Taken together, these results clearly indicated that spl5 mutation might activate both SA and JA signaling pathways and consequently trigger systematic defense responses in plants.
出处
《浙江农业学报》
CSCD
北大核心
2013年第1期1-7,共7页
Acta Agriculturae Zhejiangensis
基金
国家自然科学基金项目(31171519
31101130)
浙江省自然科学基金项目(Y3110234
Y3110230)
浙江省重点科技创新团队(2010R50024)
浙江省公益性技术应用研究计划项目(2011C22005)
关键词
水稻
类病变
spl5
抗病机理
rice
lesion mimic
spl5
disease-resistant mechanism
