Gao Yuan, Wang Mengyuan, Xie Qingjun, Sun Lili, Cao Chuanwang
Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, Heilongjiang, China; East China Academy of Inventory and Planning of NFGA, Hangzhou, 310000, China.
Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, Heilongjiang, China.
Phytochemistry. 2025 Dec;240:114625. doi: 10.1016/j.phytochem.2025.114625. Epub 2025 Jul 25.
In the constant battle with herbivorous insects, plants have evolved sophisticated recognition and adaptation mechanisms to fight insect attacks. Insect infestation is a major challenge in poplar afforestation production. In this study, we mimicked insect feeding by applying insect oral secretions (OS) to the leaf mechanical wounds of Populus davidiana × P. bolleana and combined transcriptome and hormone analyses to investigate the effects of OS from Lymantria dispar on defence responses and to identify the key genes involved in Populus davidiana × P. bolleana defence. Our results revealed that 3067 differentially expressed genes were involved in the OS-induced response to wounding in Populus davidiana × P. bolleana. OS treatment can rapidly induce the expression of genes related to the jasmonic acid (JA) biosynthetic and signal transduction pathways. The contents of JA, jasmonoyl-l-isoleucine, indole-3-acetic acid and salicylic acid significantly increased in response to OS. To construct a coexpression gene network, a hub gene annotated as WRKY22 was identified in Populus davidiana × P. bolleana. To investigate the function of the PdbWRKY22 gene against pests, PdbWRKY22 was successfully transformed into Populus davidiana × P. bolleana. Transient overexpression of PdbWRKY22 induced JA-related gene expression and suppressed the feeding behaviour of L. dispar larvae under OS treatment. These results suggested the defence mechanism of Populus davidiana × P. bolleana against L. dispar at the transcriptional and hormonal levels, and revealed that PdbWRKY22 plays a crucial physiological role in Populus davidiana × P. bolleana.
在与食草昆虫的持续斗争中，植物进化出了复杂的识别和适应机制来对抗昆虫的攻击。昆虫侵害是杨树造林生产中的一个重大挑战。在本研究中，我们通过将昆虫口腔分泌物（OS）施加到山杨×小叶杨的叶片机械伤口上模拟昆虫取食，并结合转录组和激素分析，以研究舞毒蛾的OS对防御反应的影响，并鉴定参与山杨×小叶杨防御的关键基因。我们的结果表明，3067个差异表达基因参与了山杨×小叶杨对OS诱导的伤口反应。OS处理可迅速诱导与茉莉酸（JA）生物合成和信号转导途径相关的基因表达。响应OS，JA、茉莉酰 - L - 异亮氨酸、吲哚 - 3 - 乙酸和水杨酸的含量显著增加。为构建共表达基因网络，在山杨×小叶杨中鉴定出一个注释为WRKY22的枢纽基因。为研究PdbWRKY22基因对害虫的功能，PdbWRKY22成功转化到山杨×小叶杨中。在OS处理下，PdbWRKY22的瞬时过表达诱导了JA相关基因的表达，并抑制了舞毒蛾幼虫的取食行为。这些结果揭示了山杨×小叶杨在转录和激素水平上对舞毒蛾的防御机制，并表明PdbWRKY22在山杨×小叶杨中发挥着关键的生理作用。
