A Preliminary Study On Protein Acetylation Regulation Of Bacillus Nematocida B16 Nematodes

Plant parasitic nematodes result in huge global economic losses of agricultural crops each year,which is the second largest factor that restricts agricultural production.Because of its green and safe nature,nematode biological control has gradually become a hot spot in the study of nematode control.Bacillus nematocida has good insecticidal activity against nematodes such as pine wood nematode.It has been reported in the literature that the lysine acetylation of proteins regulates physiological activities in various aspects of cells.Does protein acetylation regulate the interaction between B16 and nematodes? The acetylated protein group of B16 was sequenced by TMT（tandem mass tag）-labeled LC-MS/MS technique,and the acetylation level and protein expression level of acetylated lysine sites were quantitatively analyzed.1.A total of 349 acetylation sites were identified in 349 proteins,and acetylated proteins were analyzed using a variety of biological information methods,including COG function classification,GO enrichment analysis,KEGG pathway analysis,a nd acetylated peptide secondary structure.Analysis and motif analysis.Through these analyses,22 of these proteins were involved in the synthesis of B16-attracting nematode material.In addition,Sec A（K42）and Sec Y（K373）were involved in nematicidal protease secretion.Quantitative analysis of the effect of nematode on the expression of B16 protein in the nematicidal process.A relative quantification analysis was performed on 1592 proteins identified from the 1980 proteins.The expression levels of 13 proteins were significantly up-regulated and the expression levels of 12 proteins were significantly down-regulated.Five of the differential proteins were extracellularly enriched;chitosanase,cell membrane-linked amido-amylase,and chitin were significa ntly upregulated during the nematicidal process,and these proteins may be involved in the regulation of B16-nematode interactions.3.Quantitative analysis of the effect of nematodes on the acetylation of B16 protein during nematicidal nematodes.Relative quantification of the acetylation levels of the 411 acetylation sites of the identified 288 proteins was performed.In the process of killing nematodes,there were 24 sites for acetylation up-regulation exceeding 20%,and 27 sites for acetylation down-regulation exceeding 20%.There were significant differences in acetylation levels at 10 lysine sites,including a urinary acid hydratase involved in histidine metabolism（orf06079₁）and a superoxide dismutase involved in ROS（reactive oxygen species）metabo lism.Enzyme（orf03899₁）.These results indicate that nematodes can affect B16 protein acetylation levels.Our results showed that the lysine acetylation of the protein is indeed involved in the regulation of the nematicidal process of B16;and it was found that the nematode has a certain influence on the protein expression level of B16 and the acetylation level of the protein.These findings expand our understanding of the interaction of B16-nematode.