| Tobacco mosaic virus disease is a common and harmful disease in the production of vegetables and some major economic crops,which has caused economic losses to agricultural production.It is still challenging to reveal the interaction and response mechanism between plant host and virus through different research perspectives,and to provide a new path for plant virus disease prevention and control.In this study,Nicotiana benthamiana and Tobacco mosaic virus(TMV)were used as the main research objects.Based on proteomics and acetylation modification omics analysis,acetylated proteins in host plants responding to viral stress after TMV infection were screened,and their gene functions and acetylation modification characteristics were studied.The response mechanism of N.benthamiana after TMV infection was explored from the perspective of epigenetics.1.A total of 7218 quantifiable proteins were identified from 8828 proteins identified in N.benthamiana after TMV infection,and 1339 differentially expressed proteins were screened by proteomics and acetylation modification omics analysis.Among them,703 proteins were up-regulated and 636 proteins were down-regulated.Among the 256 differentially expressed acetylated proteins after virus infection,163 proteins were up-regulated and 93 proteins were down-regulated.There were 201up-regulated acetylation sites and 124 down-regulated acetylation sites.The differentially expressed acetylated proteins were mainly involved in fatty acid degradation and α-linolenic acid metabolism,which were involved in energy metabolism and plant disease resistance.Protein interaction network analysis identified three highly correlated acetylated protein clusters,namely “ribosome”,“carbon metabolism” and “fatty acid metabolism”.2.Targeted protein verification combined with acetylation modification omics and bioinformatics analysis results,NbACX1 protein was selected as the target protein for subsequent research,and K449 was determined as the acetylation modification site for subsequent research.The target protein coding gene NbACX1 was cloned from N.benthamiana,which encoded a protein sequence composed of 664 amino acids.Bioinformatics analysis showed that the isoelectric point of NbACX1 was 8.55 and the molecular weight was 74.28 k Da.It had three domains: the N-terminal domain of acyl-Co A oxidase composed of 17-132 amino acids,the middle-terminal domain of acyl-Co A oxidase/dehydrogenase composed of 134-236 amino acids,and the C-terminal domain of acyl-Co A oxidase composed of 480-656 amino acids.It played an important role in fatty acid metabolism and fatty acid β-oxidation.3.The expression of NbACX1 was significantly increased after TMV infection,indicating that NbACX1 was induced by TMV infection.Using virus-induced gene silencing(VIGS)technology,we found that transient silencing of NbACX1 promoted TMV replication and expression.The application of NbACX1 overexpression system showed that the overexpression of NbACX1 was beneficial to the inhibition of TMV expression in N.benthamiana.Exogenous application of methyl jasmonate(Me JA)had a significant induction effect on NbACX1,indicating that NbACX1 can participate in physiological processes such as N.benthamiana resistance to TMV by responding to jasmonic acid(JA)hormone signaling pathway.4.The response relationship between TMV infection and host plant acetylation modification was further verified from the perspective of molecular biology.It was found that the level of protein acetylation modification in N.benthamiana increased significantly after TMV infection,which was consistent with the results of acetylation modification omics.After treatment with deacetylase inhibitors,the expression of virus replication increased in the TMV-treated group.After the mutation of NbACX1K449 site to K449 R,the acetylation level of NbACX1 was down-regulated,and the replication amount after virus infection was reduced.Therefore,it was proved that TMV promoted its own replication and infection by acetylation of NbACX1. |
