小菜蛾为重要的世界性十字花科植物专食性害虫，在长期进化过程中形成了特殊的对抗寄主植物硫苷-黑芥子酶化学防御系统的机制。小菜蛾硫苷硫酸酯酶（GSS）能够与黑芥子酶竞争硫苷作为底物，产生无毒的水解产物。通过分析小菜蛾基因组和转录组数据以及初步的试验验证，我们发现GSS与其活性所必须的硫酸酯酶修饰因子1（SUMF1）基因在幼虫时期协同高表达，并推测这可能是小菜蛾能够以各类十字花科植物作为寄主的重要原因。本项目基拟在此基础上继续深入挖掘小菜蛾等昆虫基因组中的硫酸酯酶基因家族和SUMF1基因，构建小菜蛾GSS与SUMF1基因系统进化关系及响应硫苷协同表达的模式；通过RNA干扰验证两者的功能和协同关系；首次尝试定位和比较GSS与SUMF1基因启动子区域响应硫苷的核心元件，建立其协同表达的分子基础。这将为阐明昆虫对寄主植物适应性进化的多样性提供理论依据，也将为利用分子手段持续有效地控制害虫提供新的思路。

The diamondback moth (DBM), Plutella xylostella, is an important insect pest preferentially feeds on cruciferous plants worldwide. The DBM has evolved specific detoxification system for counterdefence against glucosinolate (GS)-myrosinase system of Crucifers. Glucosinolate sulfatase (GSS) of the DBM can compete with myrosinase for GS to catalyze the production of nontoxic hydrolysis. Based on the DBM genome and transcriptome data, we found that the highly co-expressed GSS and sulfatase modifying factor 1 (SUMF1) genes, which are nessary for the activation of GSS, during larval stage are likely the key enabling DBM to use a broad range of cruciferous host plants. As a futher setp of our previous work and findings, in this project, we aim at deep exploration of sulfatase gene family and SUMF1 genes from both DBM and other insect genomes for their phylogenetic relation and expression pattern in response to GS. RNA interference will be used for the functional verification of DBM GSS and SUMF1. For the first time, we are also interested in the identification and characterization of core elements from promoters of GSS and SUMF1 genes, which can response to GS for gene expression regulation, for the construction of molecular bases for GS response of each gene. This work will lay a strong theoritical foundation for better understanding the diversity in adaptive evolution of insect pest against host plant defense system, and will provide a novel aspect for effective and sustainable insect pest management.