Probenazole-induced accumulation of salicylic acid confers resistance to Magnaporthe grisea in adult rice plants
Probenazole-induced accumulation of salicylic acid confers resistance to Magnaporthe grisea in adult rice plants
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DOI：
10.1093/pcp/pcm062
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发表时间：
2007-07-01
影响因子：
4.9
通讯作者：
Ohashi, Yuko
中科院分区：
文献类型：
--
作者：
Iwai, Takayoshi;Seo, Shigemi;Ohashi, Yuko
丙磺唑（PBZ）是水稻的有效成分，是一种用于保护水稻免受稻瘟病菌（稻瘟病菌）侵害的农用化学品。虽然PBZ在拟南芥中被报道在水杨酸（SA）的上游发挥作用，但对PBZ诱导水稻抗性的机制知之甚少。SA在稻瘟菌抗性中的作用也尚不清楚。水稻的推荐施用期是在日本雨季之前，此时田间的水稻植株已达到8叶期，具有成熟性状。因此，SA参与PBZ诱导的抗性在亲和和不亲和的稻瘟病菌-水稻互作在两个发育不同的叶片形态阶段进行了研究。用PBZ预处理4叶期接种的野生型水稻幼株的第四叶不影响敏感互作中发白的扩展病斑（ELs）的发展，而不积累SA和致病相关（PR）蛋白。然而，PBZ预处理增加了SA和PR蛋白在8叶期的成年植物的第8叶中的积累，导致过敏反应（HR）病变（HRL）的形成。外源SA诱导成年植株而非幼株的抗性。在亲和和不亲和互作中，接种稻瘟病菌的幼叶中SA浓度基本相同，表明PBZ诱导的水稻抗性是通过SA积累的年龄依赖性调节的。
Probenazole ( PBZ) is the active ingredient of Oryzemate, an agrochemical which is used for the protection of rice plants from Magnaporthe grisea ( blast fungus). While PBZ was reported to function upstream of salicylic acid ( SA) in Arabidopsis, little is known about the mechanism of PBZ- induced resistance in rice. The role of SA in blast fungus resistance is also unclear. The recommended application period for Oryzemate is just before the Japanese rainy season, at which time rice plants in the field have reached the 8- leaf stage with adult traits. Thus, the involvement of SA in PBZ- induced resistance was studied in compatible and incompatible blast fungus - rice interactions at two developmentally different leaf morphology stages. Pre- treatment of inoculated fourth leaves of young wild- type rice plants at the 4- leaf stage with PBZ did not influence the development of whitish expanding lesions ( ELs) in the susceptible interaction without the accumulation of SA and pathogenesis- related ( PR) proteins. However, PBZ pretreatment increased accumulation of SA and PR proteins in the eighth leaves of adult plants at the 8- leaf stage, resulting in the formation of hypersensitive reaction ( HR) lesions ( HRLs). Exogenous SA induced resistance in adult but not young plants. SA concentrations in blast fungus- inoculated young leaves were essentially the same in compatible and incompatible interactions, suggesting that PBZ- induced resistance in rice is age- dependently regulated via SA accumulation.