Department of Bioscience, Fukui Prefectural University , Fukui, 910-1195, Japan.
Sci Rep. 2011;1:171. doi: 10.1038/srep00171. Epub 2011 Nov 25.
Rice blast caused by Magnaporthe oryzae is a devastating disease of rice. Mechanisms of rice resistance to blast have been studied extensively, and the rice-M. oryzae pathosystem has become a model for plant-microbe interaction studies. However, the mechanisms of non-host resistance (NHR) to rice blast in other plants remain poorly understood. We found that penetration resistance to M. oryzae in multiple mutants, including pen2 NahG pmr5 agb1 and pen2 NahG pmr5 mlo2 plants, was severely compromised and that fungal growth was permitted in penetrated epidermal cells. Furthermore, rice Pi21 enhanced movement of infection hyphae from penetrated Arabidopsis epidermal cells to adjacent mesophyll cells. These results indicate that PEN2, PMR5, AGB1, and MLO2 function in both penetration and post-penetration resistance to M. oryzae in Arabidopsis, and suggest that the absence of rice Pi21 contributed to Arabidopsis NHR to M. oryzae.
稻瘟病由稻瘟病菌引起，是水稻的一种毁灭性疾病。水稻对稻瘟病的抗性机制已得到广泛研究，水稻-稻瘟病菌体系已成为植物-微生物相互作用研究的模型。然而，其他植物对稻瘟病的非寄主抗性（NHR）机制仍知之甚少。我们发现，包括 pen2 NahG pmr5 agb1 和 pen2 NahG pmr5 mlo2 在内的多个突变体对稻瘟病菌的穿透抗性严重受损，并且穿透的表皮细胞中允许真菌生长。此外，水稻 Pi21 增强了感染菌丝从穿透的拟南芥表皮细胞向相邻叶肉细胞的运动。这些结果表明 PEN2、PMR5、AGB1 和 MLO2 在拟南芥中既参与稻瘟病菌的穿透抗性，也参与穿透后的抗性，并表明水稻 Pi21 的缺失导致拟南芥对稻瘟病菌的 NHR。
