从植物次级代谢物质中寻找杀虫先导化合物是创制杀虫剂的重要途径。植物乳汁是植物化学防御武器，高含量次级代谢物质及防御植食昆虫的能力，使其成为寻找杀虫成分的理想材料。植物的诱导抗性会被昆虫取食激活，应激而生的次级代谢物质对害虫有针对性的杀虫作用，以它们为目标开展研究，能减少分离的盲目性，高效的寻找杀虫成分。基于此，课题组创新性的主动利用昆虫取食苣荬菜，进而发现其乳汁应激产生大量次级代谢物质，杀虫活性也大幅提高，有拒食、胃毒、生长发育抑制等多种杀虫作用方式。初步机理研究表明，乳汁的多种杀虫活性可能与细胞诱导凋亡和重要酶活性抑制有关。综上，本研究拟采用昆虫取食诱导的研究策略，以量大质优的苣荬菜乳汁为研究材料，以其应激次级代谢物质为目标，开展化合物制备及杀虫活性测试，并在细胞、分子和组学水平上探讨其杀虫机理，以期高效快速的发掘植物源杀虫先导化合物，为农业用途的植物活性成分研究提供有效新思路。

Screening for insecticidal lead compounds from plant secondary metabolites is one of the main methods for creating new insecticides. As an important plant defense system, plant latex contains a great variety of specialized products that could protect plants against insect herbivores, which makes it an ideal material for discovering insecticide. Plant defense reactions would be triggered by insect herbivory. The secondary metabolites induced by insect attacks can act as anti-herbivory compounds, and thus can be used to search insecticidal lead compounds. Our previous studies have found that insect herbivory induced a variety of secondary metabolites in the latex of Sonchus arvensis, which largely enhanced the insecticidal activity of latex. The results of mechanism study suggested that these secondary metabolites S. arvensis latex could induce cell apoptosis and inhibit the enzyme activity in insect, and result in stomach poison, antifeedant effects and growth inhibition of insect eventually. This project aims to discover insecticidal compounds by testing the insecticidal activity of the insect herbivory-induced secondary metabolites in S. arvensis latex. The underlying mechanism of actions of these insecticidal compounds will be also analyzed in cellular, molecular and omics levels. This work will help to establish a highly efficient way to discover new botanical pesticides, and provide new ideas for developing plant active ingredients in agriculture.