Identification And Characterzation Of Carboxylesterase Genes Associated With Host Specificity In Agasicles Hygrophila

Alternanthera philoxeroides (Mart.) Griseb is one of the most key invasive weeds in China. Mary countries,like the United States, Australia, China,use host-specific natural enemy, Agasicles hygrophila Selman & Vogt to govern it and has achived great success. It is the most effective biological control measures. There are many research about the reason of host-specific, but we didn’t get a conclusion yet. The function of detoxification enzyme in insects is concerned with growth, development, feeding process. Carboxylesterase is one of insect detoxification enzymes. For research of the function of carboxylesterase in Agasicles hygrophila’feeding process, we use high-throughput sequencing technology (RNA-seq) and digital gene expression(DGE). After the different treatment of Agasicles hygrophila, two carboxylesterase are found out. We made a phylogenetic tree and characterization, while using fluorescence quantitative PCR to detect differences in gene expression, To discuss the relation of carboxylesterase expression and different treatment from the molecular level. Several studied were carried out as follows:We get many different expression genes with high-throughput sequencing technology and digital gene expression, but carboxylesterase are only two. A full-length sequence, Unigene99421 (1647bp), another one CL44865.contigl (1328bp) lost some sequence. CarE9421 �'� CarE4865 get the longest ORF 999bp �'� 330bp. CarE9421 has 548 amino acid and CarE4865 has 411 amino acid, they are both hydrophilic protein. A helix take the highest proportion in the secondary structure and β fold are the leastest. Two gene are both find in cell cytoplasm. CarE9421 contain a signal peptide and CarE4865 has no one.The full-length sequences CarE9421 were re-sequencing,3 bases are different with the result of RNA-seq, finally, we take the re-sequencing instead of the result of RNA-seq. The 563th base is T replace C, the 704th base is T replace A, the 1155th base is T replace A.The two genes both have significant differentially express after the different treated(P<0.01), compared with the express of hunger treatment with feeding Alternanthera philoxeroides,the CarE9421 of feeding group is 13.7 fold as much as the hunger group. After feeding Beta vulgaris and Alternanthera philoxeroides, the express of the CarE4865 is reduced,the different multiples is 0.28 and 0.60 fold.We use the 1-naphthyl as the substrate to test the carboxylesterase of Agasicles hygrophi (feedind Alternanthera philoxeroides、Beta vulgaris and hunger treatment). After feeding Alternanthera philoxeroides, the enzyme activity is 2.3 fold as much as the hunger treatment. Feeding Beta vulgaris and hunger treatment have no significant differences.