番茄潜叶蛾气味结合蛋白及其与四种茄科寄主挥发物的互作机制

Olfactory recognition of solanaceous host plants by Tuta absoluta

【目的】鉴定并分析番茄潜叶蛾Tuta absoluta的气味结合蛋白,解析番茄潜叶蛾对寄主定位的嗅觉识别机制,为其绿色防控提供依据。【方法】基于已公布的番茄潜叶蛾基因组数据,筛选并鉴定气味结合蛋白(Odorant-binding proteins,OBPs),对OBPs进行生物信息学分析,同源建模获得三维结构,采用Autodock软件对番茄潜叶蛾OBPs与3种挥发物配体进行分子对接模拟,并对结合特性进行分析。【结果】番茄潜叶蛾的15个OBP基因均与其他鳞翅目昆虫的OBPs有较高同源性,PabsOBPs被分为3种类型:Minus-C型(OBP9)、Plus-C型(OBP3/4/6/7/8/10/15)和Classic型(OBP1/2/5/11-14),PabsOBPs与其他鳞翅目昆虫的OBP有可信的同源进化关系。PabsOBPs和茄科作物的3种挥发物有较强结合能力,主要以疏水作用力和氢键相结合,其中PabsOBP2与番茄特有挥发物2-蒈烯具有强结合力,PabsOBP8和PabsOBP9可分别与茄科作物共有挥发物2-戊基呋喃和反-2-己烯醛结合。【结论】明确了番茄潜叶蛾15个PabsOBPs和与3种寄主挥发物分子的相互作用关系,其中PabsOBP2可精准识别番茄特有挥发物2-蒈烯,为开发基于行为调控的番茄潜叶蛾绿色防控技术提供了理论依据。

[Aim]To identify and analyze the odorant-binding proteins(OBPs)of Tuta absoluta,and elucidate the olfactory recognition mechanism it uses to locate hosts,thereby providing a theoretical basis for the environmentally friendly control of this pest.[Methods]Based on published genome data for T.absoluta,OBP genes were screened and identified,and bioinformatics analysis and homologous modeling was performed to obtain the genes’three-dimensional structure.Autodock software was used to simulate molecular docking between PabsOBPs and three volatile ligands,and the genes’binding characteristics were analyzed.[Results]BLAST analysis showed that 15 OBP genes of T.absoluta had high homology with OBPs of other lepidopteran insects.Multiple sequence alignment of PaOBPs classified all OBPs into three types:Minus-C type OBPs(OBP9),Plus-C type OBPs(OBP3/4/7/6/8/10/15),and Classic OBPs type(OBP1/2/5/11-14).A phylogenetic tree indicated a credible,homologous,evolutionary relationship between the OBP genes of T.absoluta and those of other lepidopteran insects.The results of molecular docking indicate that PabsOBPs have strong binding ability for three volatiles of solanaceous hosts.PabsOBP2 has strong binding affinity for the tomato volatile 2-carene,whereas PabsOBP8 and PabsOBP9 bind to the solanaceous host plant volatiles 2-pentylfuran and(e)-2-hexenal,respectively.PabsOBPs bind to these three host volatiles mainly by hydrophobic force and hydrogen bonding.[Conclusion]15 OBP genes of T.absoluta were identified and analyzed,and the interaction between 15 PabsOBPs and 3 host volatiles was elucidated.PabsOBP2 could accurately identify 2-carene,a volatile specific to tomato plants.These results provide a theoretical basis for the development of behavior-based,environmentally-friendly methods of controlling T.absoluta.