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烟粉虱为重要的入侵性经济作物害虫,对入侵地寄主植物存在选择性和偏好性。为明确烟粉虱气味结合蛋白(odorant binding protein,OBPs)的相关特性,通过克隆其OBP8基因Btab OBP8,进行同源基因进化关系分析,构建原核表达载体诱导表达重组蛋白,并利用基于荧光探针N-苯基-1-萘胺(N-phenyl-1-naphthylamine,1-NPN)的荧光竞争结合试验测试了Btab OBP8与不同寄主植物挥发物的结合功能。结果表明,Btab OBP8基因的开放阅读框全长480 bp,编码159个氨基酸,与半翅目其它害虫的OBP8基因进化关系较远。Btab OBP8蛋白重组后,4种化合物即β-紫罗兰酮、月桂烯、柠檬烯和P-伞花烃将1-NPN的相对荧光强度降低到50%以下,其中β-紫罗兰酮和月桂烯与Btab OBP8的结合能力最强,解离常数分别为13.32μmol/L和21.53μmol/L。表明β-紫罗兰酮和月桂烯与Btab OBP8具有良好的亲和力,推测Btab OBP8对β-紫罗兰酮和月桂烯的识别可能参与了烟粉虱对绿色开花植物的吸引和选择作用。
Bemisia tabaci (B. tabaci) is an important invasive pest of economic crops and has selectivity and preference for host plants invaded. In order to clarify the related characteristics of odorant binding protein (OBPs) of Bemisia tabaci, the OBP8 gene Btab OBP8 was cloned and the phylogenetic relationship was analyzed. The prokaryotic expression vector was induced to express the recombinant protein, N-phenyl-1-naphthylamine (N-phenyl-1-naphthylamine, 1-NPN) was used to test the binding of Btab OBP8 to different host plant volatiles. The results showed that the open reading frame of Btab OBP8 gene is 480 bp in length and encodes a protein of 159 amino acids, which is more distantly related to the OBP8 gene of other pests in Hemiptera. Four compounds, β-ionone, myrcene, limonene and p-cymene, reduced the relative fluorescence intensity of 1-NPN to less than 50% after Btab OBP8 protein was reconstituted, among which β-ionone and myrcene reacted with Btab OBP8 The binding capacity was the strongest, the dissociation constants were 13.32μmol / L and 21.53μmol / L respectively. The results showed that β-ionone and myrcene have good affinity with Btab OBP8. It is speculated that the recognition of β-ionone and myrcene by Btab OBP8 may be involved in the attraction and selection of green flowering plants by B. tabaci.