The Bemisia Tabaci Population Differentiation Mechanism Induced By Host Plant

In this study, B biotype Bemisia tabaci populations reared on 5 different host plants, including cabbage, cucumber, tomato, cotton and poinsettia, for more than 4 years from a parent strains were used as tested materials. Firstly, from the point of experiment ecology, long-term induction effects of host plants on the insecticide susceptibility and detoxification enzyme activities were investigated. Then, multiple generation induction effects of host plants on the nutrient and biochemical mechanisms of B. tabaci adults were also evaluated. Secondly, transcriptome of B. tabaci in different developmental stages were sequenced and gene expression profile of different B. tabaci host populations were carried out to evaluate the molecular mechanism of host plant induction. Thirdly, at the basis of above, a microarray of metabolism detoxification genes was designed to lay the foundation of pesticides susceptibility induction mechanism from host plants. The main results and conclusions were as follows:(1) Induction effects on insecticide susceptibility and detoxification enzymes of Bemisia tabaci from 5 different host plants. The results of insecticide susceptibility measurement showed that except for bifenthrin, all the other tested insecticides showed lower toxicity to B. tabaci poinsettia population compared with other host populations. Physiological and biochemical studies revealed that the CarE activities of B. tabaci cabbage and cucumber populations were all significantly higher than that of poinsettia, cotton, and tomato populations. The GST and P450 activities of cucumber population were the lowest among the five host populations. (2) Multi-generation induction effect on the nutrient metabolism and biochemical characters of Bemisia tabaci from 3 different host plants. The results showed that significantly higher protein content was found in B.tabaci adults fed on cucumber compared with poinsettia after transferring for 1, 3 and 6 months. Trehalase activity significantly increased in B.tabaci adults fed on cabbage compared with cucumber and poinsettia after transferring for 3 and 6 months. (3) Transcriptome research of Bemisia tabaci. Through pretreatment of raw reads, over 0.3 billion bases of high-quality sequences were generated. After assembly, 178669 unigenes were totally obtained. Through the analysis of Meta-transcriptome, some new bacteria genus in B.tabaci was found including Delftia, Serratia, Stenotrophomona, Bordetella and so on. (4) The expression profile of Bemisia tabaci populations after long-term induction from host plants. Within the groups of host populations of B-biotype, the difference of cu-vs-to (cucumber population to tomato population, named as cu-vs-to, the same as belows) was smallest which contained 25 genes representing significantly up and down concerning 5 pathways. In the meanwhile, the difference of ca-vs-co was the biggest containing 855 genes representing significantly up and down concerning 46 pathways. (5) The design of metabolic detoxification microarray in Bemisia tabaci. In order to demonstrate the differences of about metabolic detoxification in B. tabaci populations from host induction, a microarray of metabolism detoxification genes in B. tabaci was designed. In total, the array containing 1.5K×8 standard of Agilent containing 8622 reasonable probes was obtained.