NbRbohB基因在本氏烟与疫霉菌互作中的功能分析

活性氧(active oxygen species, AOS)在植物抗病中发挥着重要作用,主要由NADPH氧化酶(nicotinamide adenine dinucleotide phosphate oxidase)系统产生.为明确NADPH氧化酶NbRbohB基因在本氏烟与疫霉菌亲和与非亲和性互作中的功能,采用荧光定量PCR技术以及病毒诱导的基因沉默方法探究了NbRbohB基因在本氏烟中对2种疫霉菌抗性中的作用,并利用NADPH氧化酶抑制剂对辣椒疫霉的抗性进行了检测.结果发现:2种疫霉菌均能诱导本氏烟发生氧迸发,且NbRbohB基因可能参与了疫霉菌诱导本氏烟发生的氧迸发过程.该基因沉默后降低了本氏烟对亲和互作辣椒疫霉菌的抗性,但对非亲和互作疫霉菌的抗性没有肉眼可见的影响;NADPH氧化酶抑制剂处理本氏烟后也能降低其对辣椒疫霉的抗性.表明该基因通过介导AOS产生,参与植物对亲和性与非亲和性互作疫霉的抗病反应,在亲和互作中尤为重要.

NbRbohB is required for resistance to Phytophthora pathogens in Nicotianaben thamiana

Active oxygen species (AOS) play a key role in plant defense responses, whereas NADPH oxidase is a major component in AOS production. In order to determine the roles of Nicotiana benthamiana NbRbohB gene in resistance to Phytophthora spp., including compatible (P.capsici) and incompatible (P.sojae) pathogens, real-time PCR, virus-induced gene silencing and NADPH oxidase inhibitor were used to investigate the roles of NbRbohB gene and NADPH oxidase. Obvious oxidative burst was observed in N.benthamiana leaves during infection of both Phytophthora pathogens. Real-time PCR results indicated that the gene might participate in the oxidative burst process. The resistance of N.benthamiana to P.capsici was significantly impaired in the NbRbohB gene-silenced plants. However, the resistance level to the incompatible P.sojae was not altered. Pre-treatment of the N.benthamiana leaves with NADPH oxidase inhibitor also reduced the resistance to P.capsici. These results indicated that NbRbohB was involved in the interactions of N.benthamiana-Phytophthora spp., and essential for its resistance to P.capsici.