The Identification And Functional Confirmation Of Horizonial Transferred Pectin Methylesterase Gene In Bemisia Tabacci

In nature,plants respond to insects with different feeding mechanisms through complex defense systems.With the co-evolution,insects have evolved the ability to evade plant defense system and improve their feeding ability.In this evolutionary process,horizontal gene transfer plays an important role.Bemisia tabaci is a worldwide pest that causes serious damage to crop production.Analysis of genome data of B.tabaci revealed that there were a large number of horizontally transferred genes(HTGs)in B.tabaci,but the function of these genes in B.tabaci was still unclear.Pectin methylesterase(PME)belongs to the carbohydrate esterase family CE-8.Its main function is to regulate the degree of methyl esterification of pectin,the main component of cell wall.It can directly or indirectly participate in plant defense reaction.In the genome of B.tabaci,we screened a pectin methylesterase gene.In this study,we analyzed the structure and function of this gene to provided a theoretical basis for the study of horizontal gene transfer in B.tabaci.By genome alignment,gene cloning and structural analysis,the characteristics of this gene were confirmed.BtPME was confirmed to be from plants and inserted into B.tabaci genome by some mechanism through homologous sequence evolution tree analysis.The expression patterns of BtPME in different developmental stages and tissues of B.tabaci were quantitatively analyzed by quantitative real-time reverse transcription polymerase chain reaction(qRT-PCR).The function of BtPME was studied by RNAi method and tobacco transgenic technology.The results showed that BtPME promoted B.tabaci feed by inducing SA signal pathway in host plants,and then made B.tabaci"perform"well in host plants.Based on the above research,we confirmed the function of horizontal transfer gene BtPME in B.tabaci,and proved that PME obtained by horizontal gene transfer played a very important role in B.tabaci.This study laid a foundation for the horizontal transfer mechanism of B.tabaci,and provided a new research direction for green control of B.tabaci.