非亲和性稻瘟病菌对水稻的诱导抗性

为研究稻瘟病菌Magnaporthe oryzae不同菌株间的相互作用，选择与单抗性基因系水稻IRBL5-M （携带抗性基因Pi5）表现为亲和性的菌株HN52与非亲和性的菌株HN119为研究对象，将其单独或混合接种到单抗性基因系水稻IRBL5-M中，并通过荧光显微镜观察接种后水稻叶鞘的发病情况及病斑面积，测定接种后水稻内相关抗性基因OsWRKY45、OsNPR1、OsPR10、OsMAPK2的表达量以及活性氧的变化。结果显示，相较于单独接种亲和性菌株，混合接种后单抗性基因系水稻IRBL5-M病斑发病面积减少；混合接种中亲和性菌株HN52菌丝侵染能力降低，侵染菌丝细胞间扩展率显著降低73.13%；同时单抗性基因系水稻IRBL5-M中OsWRKY45、OsNPR1、OsPR10和OsMAPK2抗性基因表达量显著增加，水稻叶片中活性氧含量增加，表明在菌株混合侵染过程中，非亲和性菌株可通过激发水稻的抗性反应来降低亲和性菌株对水稻的侵染程度。

Rice resistance induced by incompatible rice blast fungus Magnaporthe oryzae

In order to explore the interactions between different isolates of rice blast fungus Magnaporthe oryzae, compatible and incompatible isolates to single monogenic rice line IRBL5-M(Pi5)were selected and inoculated on rice by either individual or mixed way. The disease level on rice leaf sheath was observed under fluorescent microscope, the expression levels of rice resistance-related genes OsWRKY45, OsNPR1,OsPR10 and OsMAPK2 and the infection of mycelia, and the reactive oxygen species (ROS) content in rice leaves after inoculation were tested. The results showed that, the disease incidence area decreased after mixed inoculation compared with individual inoculation; the infection degree of mycelia was weakened, and intercellular expansion rate of infection mycelia were decreased by 73.13%; meanwhile, expression levels of resistance genes OsWRKY45, OsNPR1, OsPR10 and OsMAPK2 in IRBL5-M were obviously elevated, and the content of ROS in rice leaves was also increased. Ours results suggest that rice resistance induced by incompatible strains during the mixed inoculation may reduce the infection level of compatible strains.