Functional Analysis Of The Acetylated Protein BcYak1 In Virulence Of Botrytis Cinerea

Botrytis cinerea,a necrotrophic plant pathogen,can cause grey mold on more than 400 plant species.With the enlargement of the area of protected cultivation,grey mold spreads rapidly.The financial impact of grey mould is enormous because B.inerea causes both pre-and post-harvest losses.In 2012,B.cinerea was rated as one of the top ten fungal pathogens on plants,which cause huge economic impact,and rank 2.In addition,control of this disease has become a major challenge for vegetables,fruit production due to development of fungicide resistance.So far,chemical control is still the most effective method to control the occurrence and spread of grey mould.Therefore,it is essential to study the pathogenesis of B.cinerea and find novel drug targets for controlling grey mold.Lysine acetylation is one of the most common post-translational modifications(PTMs)to proteins in both eukaryotes and prokaryotes.However,to date,little is known about the functions of lysine acetylation in this plant pathogen.In this study,we determined the lysine acetylome of B.cinerea through the combination of affinity enrichment and high-resolution LC-MS/MS analysis.Overall,1582 lysine acetylation sites in 954 proteins were identified.Bioinformatics analysis shows that the acetylated proteins are involved in diverse biological functions and show multiple cellular localizations.Interestingly,6 proteins involved in virulence of B.cinerea,including 3 key components of the high-osmolarity glycerolpathway,were found to be acetylated,suggesting that lysine acetylation plays regulatory roles in pathogenesis.In this study,we analysed the functions of BcYakl,a acetylated protein in B.cinerea,both in the pathogenicity and growth.Biological functions of the gene were analyzed by gene deletion and complementation,furthermore,we obtained knock out mutant,?BcYak1 and complementation transformant,ABcYaklc.Results showed that,compared with wild type,?BcYak1 not only had reduced hyphal growth rate,conidiation and sclerotium,but also became more susceptible to a series of stress.More importantly,acetylated BcYakl has been found involved in the regulation of virulence in B.cinerea,and the deletion mutant of BcYak1(?BcYak1),an unreported acetylated protein exhibited dramatically decreased virulence on tomato leaves.Further study showed that ABcYakl was unable to penetrate onion epidermis.However,complementation transformant,ABcYaklc demonstrated the same level with wild type in the above aspects.These data provides the first comprehensive view of the acetylome of B.cinerea and serves as a rich resource for functional analysis of lysine acetylation in this plant pathogen.Expected results from this project will be helpful for revealing the role of histone acetylation in virulence of B.cinerea and providing scientific basis for novel drugs development against B.cinerea.