Dendrolimus punctatus is an important pest affecting Masson pine (Pinus massoniana L.) forests and can cause serious economic and ecological losses. WRKY transcription factors play important roles in coping with various environmental stresses. In particular, recent studies have shown that WRKY transcription factors play an important role in plant responses against herbivorous insects. However, the mechanisms underlying the actions of these genes in the defense responses of P. massoniana L. are still unclear. Our previous study provided evidence that WRKY may play an important role in the insect resistance of P. massoniana L. In this study, application of semiochemicals such as exogenous hormones and Ca2+ by spraying increased the concentrations of endogenous hormones, terpenoid synthases, and volatile substances in P. massoniana L. and effectively improved its resistance to D. punctatus. After analyzing the WRKY family of P. massoniana L., the PmWRKY31 gene was selected and studied. Yeast two-hybrid assays showed that the LP8 gene interacted with PmWRKY31. Fluorescence-based quantitative polymerase chain reaction showed that after treatment with exogenous hormones and Ca2+, the expression levels of the PmWRKY31 gene, hormonal signal–related genes, and terpene biosynthetic pathway–related genes were significantly increased, whereas the expression of the LP8 gene was decreased. Therefore, the PmWRKY31 and LP8 genes affected downstream gene expression by positively and negatively regulating the hormone signaling pathways, respectively. This result provides theoretical support for the involvement of WRKY transcription factors in the insect resistance of P. massoniana L. through their regulation of hormone signaling.

中文翻译：

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信号化合物和WRKY31在马尾松抗马尾松毛虫的防御中的作用

马尾松毛虫（Dendrolimus punctatus）是一种影响马尾松（Pinus massoniana L.）森林的重要害虫，会造成严重的经济和生态损失。WRKY转录因子在应对各种环境压力中起着重要作用。特别是，最近的研究表明，WRKY转录因子在植物对草食性昆虫的反应中起着重要作用。但是，尚不清楚这些基因在马尾假单胞菌防御反应中的作用机制。我们以前的研究提供了证据，表明WRKY可能在马尾假单胞菌的昆虫抗性中发挥重要作用。在这项研究中，通过喷洒外源激素和Ca2 +等化学信息素的应用增加了内源激素，萜类合酶和挥发性物质的浓度在马尾松 并有效提高了其​​对马尾松毛虫的抵抗力。在分析马尾假单胞菌的WRKY家族后，选择并研究了PmWRKY31基因。酵母两杂交试验表明，LP8基因与PmWRKY31相互作用。基于荧光的定量聚合酶链反应显示，在用外源激素和Ca2 +处理后，PmWRKY31基因，激素信号相关基因和萜烯生物合成途径相关基因的表达水平显着增加，而LP8基因的表达则有所增加。减少了。因此，PmWRKY31和LP8基因分别通过正向和负向调节激素信号通路来影响下游基因表达。该结果为WRKY转录因子参与马尾假单胞菌的抗性提供了理论支持。