College of Environment and Plant Protection, Hainan University, Haikou, China.
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
Insect Sci. 2020 Feb;27(1):49-57. doi: 10.1111/1744-7917.12630. Epub 2018 Aug 23.
In agro-ecosystems, plants are important mediators of interactions between their associated herbivorous insects and microbes, and any change in plants induced by one species may lead to cascading effects on interactions with other species. Often, such effects are regulated by phytohormones such as jasmonic acid (JA) and salicylic acid (SA). Here, we investigated the tripartite interactions among rice plants, three insect herbivores (Chilo suppressalis, Cnaphalocrocis medinalis or Nilaparvata lugens), and the causal agent of rice blast disease, the fungus Magnaporthe oryzae. We found that pre-infestation of rice by C. suppressalis or N. lugens but not by C. medinalis conferred resistance to M. oryzae. For C. suppressalis and N. lugens, insect infestation without fungal inoculation induced the accumulation of both JA and SA in rice leaves. In contrast, infestation by C. medinalis increased JA levels but reduced SA levels. The exogenous application of SA but not of JA conferred resistance against M. oryzae. These results suggest that pre-infestation by C. suppressalis or N. lugens conferred resistance against M. oryzae by increasing SA accumulation. These findings enhance our understanding of the interactions among rice plant, insects and pathogens, and provide valuable information for developing an ecologically sound strategy for controlling rice blast.
在农业生态系统中，植物是其相关草食性昆虫和微生物相互作用的重要中介，一种物种对植物的任何改变都可能导致与其他物种相互作用的级联效应。通常，这种效应受植物激素（如茉莉酸（JA）和水杨酸（SA））调节。在这里，我们研究了水稻植株、三种昆虫草食性（二化螟、稻纵卷叶螟或褐飞虱）和稻瘟病菌（稻瘟病菌）之间的三方相互作用。我们发现，水稻在被二化螟或褐飞虱侵害之前，而不是被稻纵卷叶螟侵害，会对稻瘟病菌产生抗性。对于二化螟和褐飞虱，昆虫的侵害而没有真菌接种会诱导水稻叶片中 JA 和 SA 的积累。相比之下，稻纵卷叶螟的侵害会增加 JA 水平但降低 SA 水平。SA 的外源应用而不是 JA 的应用赋予了对稻瘟病菌的抗性。这些结果表明，二化螟或褐飞虱的先期侵害通过增加 SA 积累赋予了对稻瘟病菌的抗性。这些发现增强了我们对水稻植物、昆虫和病原体之间相互作用的理解，并为开发控制稻瘟病的生态合理策略提供了有价值的信息。
