| The pine wilt disease caused by Bursaphelenchus xylophilus has greatly damaged forest ecosystems worldwide.B.xylophilus was first discovered in 1982 in Nanjing’s Sun Yat-sen Tomb,and although every effort has been made to prevent and control the spread of the disease,the disease has spread to nearly 19 provinces and cities,causing losses of up to 100 billion yuan in economic and ecological value.With the continuous development of science and technology,research on B.xylophilus has shifted from epigenetic studies to more precise transcriptomic studies,exploring more deeply the fields of pathogenicity,resistance,growth and development,and detoxification of B.xylophilus.Currently,chemical control is still the main tool to control B.xylophilus,but chemical nematicides maybe lead to environmental pollution and drug resistance problems.In order to effectively address the adverse effects of chemical control,it is necessary to study the detoxification genes of B.xylophilus that interact with exogenous nematicidal substances from the perspective of transcriptomics,and use them as new targets to develop new plant-derived nematicides.In this study,firstly screened the UDP-glucuronyltransferase gene family of B.xylophilus by comparative analysis of transcriptome data of B.xylophilus treated with different concentrations ofβ-pinene and rotenone.Bioinformatics was then used to analyze the role of UGT gene family members in resistance to exogenous nematicidal substances in B.xylophilus.Finally,the insecticidal activity of different concentrations ofα-pinene,β-pinene and carvone on B.xylophilus was determined to screen out the optimal treatment concentration and time,and the function of Bx UGTs in B.xylophilus was quantified by RT-q PCR based on the treatment of B.xylophilus under these conditions,which provided a theoretical and directional innovation for the control of B.xylophilus.The main results are as follows:1.The transcriptome data of B.xylophilus under different concentrations ofβ-pinene and rotenone treatment were comparatively analyzed.The transcriptome data were downloaded from the database,and the key gene families of B.xylophilus responding to exogenous nematicide substances were screened by data quality control,sequence comparison,expression quantification and differential genes analysis.The results showed that a total of 18 genes were jointly and significantly regulated under different treatments,among which the UGT gene family of B.xylophilus belonging to BXYJ＿LOCUS3192 clearly played a detoxification function and no related study had been conducted yet,so this family was selected for subsequent studies.2.The UGT gene family of B.xylophilus was analyzed by bioinformatics methods.The genome-wide data were used to identify the members of the UGT gene family,and then the specific functions of the gene family were investigated by physicochemical analysis,phylogenetic analysis,chromosomal localization,gene structure and conserved motif analysis,and gene expression profile of Bx UGTs in B.xylophilus under different treatments.The results showed that there were 47 members of the UGT gene family,with amino acid lengths ranging from 145 to 1,704 residues and relative molecular weights ranging from 16,549.93 to196,091.9 Da.The entire gene family was divided into eight different subfamilies,which were concentrated on the first six chromosomes of B.xylophilus.The gene structure and conserved motif composition varied among members,but members of the same subfamily had similar conserved motifs.There were obvious interactions between members of the UGT gene family and exogenous nematicidal substances,especially Bx UGT13,Bx UGT14 and Bx UGT16.3.The insecticidal activity of different concentrations ofα-pinene,β-pinene and carvone against B.xylophilus was analyzed to find the optimum treatment concentration and time,and the B.xylophilus were treated on this basis,and then the changes of gene expression of Bx UGT13,Bx UGT14 and Bx UGT16 in B.xylophilus were analyzed by RT-q PCR test.The results showed that the insecticidal activity of carvone was higher in B.xylophilus,the LC50 at24 h of the three plant-derived nematicides was more representative,the Bx UGTs expressed different functions in response to different exogenous nematicidal substances,and the Bx UGT16 in B.xylophilus played an important detoxification function during the resistance of nematodes to exogenous nematicidal substances.In summary,this paper explored the functions of the UGT gene family in resistance to exogenous nematicidal substances,clarified the detoxification function of the UGT gene family,and provided a new entry point for revealing the detoxification mechanism of B.xylophilus,a new target for developing new plant-derived nematicides,and a new direction for controlling B.xylophilus. |
