In response to infestation by herbivores, rice plants rapidly biosynthesize defense compounds by activating a series of defense-related pathways. However, which defensive compounds in rice are effective against herbivores remains largely unknown. We found that the infestation of white-backed planthopper (WBPH) Sogatella furcifera gravid females significantly increased levels of jasmonic acid (JA), jasmonoyl-isoleucine (JA-Ile) and H₂O₂, and reduced the level of ethylene in rice; levels of 11 of the tested 12 phenolamides (PAs) were subsequently enhanced. In contrast, WBPH nymph infestation had no effect on levels of JA, JA-Ile, ethylene and H₂O₂ in rice, and enhanced levels of only 2 of 12 PAs. Moreover, infestation by brown planthopper Nilaparvata lugens gravid females also affected the production of these PAs differently. Bioassays revealed that 4 PAs – N-feruloylputrescine, N-feruloyltyramine, feruloylagmatine and N1,N10-diferuloylspermidine – were toxic to newly emerged WBPH female adults. Our results suggest that WBPH- or BPH-induced biosynthesis of PAs in rice seems to be shaped primarily by the specific profile of defense-related signals elicited by the herbivore and that PAs play a role in conferring the resistance to WBPH on rice.

为了应对食草动物的侵扰，水稻植物通过激活一系列防御相关途径快速生物合成防御化合物。然而，水稻中的哪些防御化合物对食草动物有效仍然未知。我们发现，白背飞虱（WBPH）白背飞虱妊娠雌虫的侵扰显着增加了水稻中茉莉酸（JA）、茉莉酰异亮氨酸（JA-Ile）和H ₂ O ₂的水平，并降低了乙烯水平；所测试的 12 种酚酰胺 (PA) 中有 11 种的水平随后得到提高。相比之下，白背飞虱若虫侵染对水稻中的 JA、JA-Ile、乙烯和 H ₂ O ₂水平没有影响，仅提高了 12 个 PA 中的 2 个水平。此外，褐飞虱怀孕雌性褐飞虱的侵染也对这些 PA 的产生产生不同的影响。生物测定显示，4 种 PA——N-阿魏酰腐胺、N-阿魏酰胺、阿魏酰精胺和 N1,N10-二阿魏酰亚精胺——对新出现的 WBPH 雌性成虫具有毒性。我们的结果表明，水稻中 WBPH 或 BPH 诱导的 PA 生物合成似乎主要是由草食动物引发的防御相关信号的特定特征决定的，并且 PA 在赋予水稻对 WBPH 的抗性方面发挥着作用。