Deng Qinyu, Zhang Xiaohan, Chen Huan, Hao Mengqi, Li Ran, Lou Yonggen, Lu Jing
State Key Laboratory of Rice Biology and Breeding & Ministry of Agriculture Key Laboratory of Agricultural Entomology, Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Insect Sciences, Zhejiang University, Hangzhou, Zhejiang, China.
Hainan Institute, Zhejiang University, Sanya, Hainan, China.
Plant Cell Environ. 2024 Nov;47(11):4416-4431. doi: 10.1111/pce.15024. Epub 2024 Jul 15.
Plant-mediated interactions between herbivores play an important role in regulating the composition of herbivore community. The fall armyworm (FAW), Spodoptera frugiperda, which has become one of the most serious pests on corn in China since it invaded in 2018, has been found feeding rice in the field. However, how FAW interacts with native rice insect pests remains largely unknown. Here, we investigated the interaction between FAW and a resident herbivore, striped stem borer (SSB, Chilo suppressalis) on rice. The infestation of rice leaf sheaths (LSs) by SSB larvae systemically enhanced the level of jasmonic acid (JA), abscisic acid (ABA), and trypsin proteinase inhibitors (TPIs), reduced relative water content (RWC) in leaf blades (LBs), and suppressed the growth of FAW larvae. In contrast, because FAW larvae infested LBs and did not affect defence responses in LSs, they did not influence the performance of SSB larvae. Using different mutants, together with bioassays and chemical analysis, we revealed that SSB-induced suppression of FAW larvae growth depended on both the SSB-activated JA pathway and RWC in LBs, whereas the ABA pathway activated by SSB larvae promoted the growth of FAW larvae by impeding water loss. These results provide new insights into mechanisms underlying plant-mediated interactions between herbivores.
植物介导的植食性昆虫之间的相互作用在调节植食性昆虫群落组成方面发挥着重要作用。草地贪夜蛾（FAW），即草地贪夜蛾（Spodoptera frugiperda），自2018年入侵以来已成为中国玉米上最严重的害虫之一，现已发现其在田间取食水稻。然而，草地贪夜蛾如何与本地水稻害虫相互作用在很大程度上仍不清楚。在此，我们研究了草地贪夜蛾与水稻上的常住植食性昆虫二化螟（SSB，Chilo suppressalis）之间的相互作用。二化螟幼虫对水稻叶鞘（LS）的侵染系统性地提高了茉莉酸（JA）、脱落酸（ABA）和胰蛋白酶蛋白酶抑制剂（TPI）的水平，降低了叶片（LB）中的相对含水量（RWC），并抑制了草地贪夜蛾幼虫的生长。相反，由于草地贪夜蛾幼虫侵染叶片且不影响叶鞘中的防御反应，它们对二化螟幼虫的生长表现没有影响。通过使用不同的突变体，结合生物测定和化学分析，我们发现二化螟诱导的对草地贪夜蛾幼虫生长的抑制依赖于二化螟激活的JA途径和叶片中的相对含水量，而二化螟幼虫激活的ABA途径通过阻碍水分流失促进了草地贪夜蛾幼虫的生长。这些结果为植物介导的植食性昆虫之间相互作用的潜在机制提供了新的见解。
