Identification And Functional Analysis Of FAR Gene Family In Bemisia Tabaci

Bemisia tabaci is a global agricultural pest that seriously harms flowers,vegetables and crops in my country.It can not only directly suck the juice of plants and cause plants to wilt,but also carry viruses to cause plant diseases,and the honeydew it secretes is also easy to cause Sooty plant disease.The invasive Btype whitefly(MEAM1 cryptic species)and Q-type B.tabaci(MED cryptic species)have strong adaptability and fast reproductive ability,and have become the main whitefly cryptic species in my country.By consulting a large number of literatures,it is found that the FAR is well conserved,and it exists in almost all biological species from bacteria to fungi,plants,and animals.In insect research,it is found that the FAR plays a variety of roles.The FAR mainly reduces different saturated fatty acids into fatty alcohols,and then forms different wax lipids through synthetases.In this study,the functional verification was carried out by screening the FAR of type B whitefly,and the test results are as follows:(1)21 genes were obtained through de-redundancy processing of B.tabaci FAR downloaded from the existing public gene database.In this study,using local and online gene sequence analysis software,it was concluded that among the 21 genes of the B.tabaci FAR family,1 gene is an acidic amino acid,and the other 20 are basic amino acids;the B.tabaci FAR family There are 12 conserved motifs in protein sequences,and most gene protein sequences contain more than 8 conserved motifs and are roughly the same.It indicated that the FAR family of B.tabaci was relatively conserved and relatively stable.Through phylogenetic tree analysis with other biological FAR,it was found that all FAR have high homology and high conservation,and the members of the FAR family of type B bemisia tabaci are distributed in each large branch,which shows that The FAR has multiple functions in B.tabaci.According to the conserved motifs contained in the closer branches of the phylogenetic tree,the genes in the same branch may perform the same function.It was deduced that the BtFAR11 gene may be involved in the synthesis of cuticular wax layer in Bemisia tabaci.(2)By using real-time fluorescence quantitative PCR to detect and analyze the spatiotemporal expression of the FAR family in type B whitefly bemisia tabaci,it is concluded that among the relative expression levels of 21 genes in different parts,the BtFAR6 is in the male adult The relative expression level of BtFAR14 is the highest in the thorax of adult worms,followed by the head of male adults;the relative expression level of BtFAR11 is the highest in the abdomen of adult worms;the highest expression level of BtFAR7 is in the 4th instar nymphs;BtFAR12 is the highest expression level in the thorax of female adults.Combining the comparative analysis of phylogenetic tree and the study of FAR in white wax insect,it is inferred that BtFAR11 is involved in the formation of cuticular wax in type B bemisia tabaci,and plays a role in resisting external environment,water retention and drought resistance to bemisia tabaci.(3)After silencing the BtFAR11 of B.tabaci by using the leaf-mediated method,they continued to be reared under different humidity conditions.The results showed that the body surface of the B.tabaci in the BtFAR11 silencing group was significantly more waxy than the control group.reduce.Under dry environmental conditions(RH=10%),there was no significant change in the control group,but the mortality rate in the gene silencing group was 53%,which had a very significant difference.Moreover,the weight loss rate of the gene silencing group is higher than that of the control group,which has a very significant difference.The weight loss rate is more obvious.The body appearance of Bemisia tabaci in dry conditions with the silenced genome mainly showed that the body color became heavier,and the epidermis shriveled and shriveled,and the water loss was serious.This study proves that the BtFAR11 target gene silencing Bemisia tabaci is more sensitive to the external environment,and it is easy to lose water in a dry environment,thereby increasing the mortality rate..