Effect Of ClpA ATPase In Xanthomonas Campestris Pv Malvacearum On Adverse Stress

Cotton angular leaf spot,caused by Xanthomonas campestris pv.Malvacearum(Xcm)is an important plant disease widely distributed all cotton growth area.In history,as theCotton a ngular leaf spot was less harmful,It did not cause enough attention.In recent years,with the change of climate conditions,especially the planting on sea island,disease of the Cotton a ngular leaf spot increase year by year.About the Cotton a ngular leaf spot,we lack of the knowledge of pathogen pathogenicity and environmental adaptability.Studying of pathogen pathogenic mechanism and environmental adaptabilityt of the Cotton a ngular leaf spot,helps us to understand the Cotton a ngular leaf spot.Thus we can develop effective disease control measures.ATPases associated with a variety of cellular activities are multisubunit assemblies that degrade protein substrates in all kingdoms of life.They have a two-component overall architecture consisting of a proteolytic cylinder lined with protease active sites and a ring-shaped chaperone complex.The shared architecture underlies a common mechanism of action.The chaperone rings bind to the ends of the proteolytic cylinder,acting as “entry guards”,and they represent the site of recognition for potential protein substrates.After recognizing and binding substrates,the chaperones unfold and thread them into the proteolytic channel where they are then degraded into small peptides.Clp Widely exists in the organism,which is highly conservative.It can control the metabolic processes of the organism,by regulating the rate-limiting enzyme,the organism protein metabolism plays an important role in regulating.Clp mainly degrades the wrong folded and damaged proteins,to ensure the cells can exercise its physiological function.Clp A belongs to ATP-dependent molecular chaperone,The ClpA chaperone is required for substrate recongnition and unfolding and for translocation of the unfolded substrate to the ClpP active sites,these processes needs ATP hydrolysising to provide energy.ClpAP is a roughly ATP-dependent protease complex comprising a double-ringed tetradecameric ClpP protease core flanked by a hexameric ClpA ring on one or both ends.As a good model system to study the effects of the Clp/Hsp100 protein mechanism.Clp A not only can rely on ATP to unfold,but also is a key to Clp AP hydrolysis.Although many articles about the structure and function of ClpA have been reported,but the function of clpA gene in theXanthomonas campestris pv malvacearum has not been reported.In order to study the function of clpA gene in the Xanthomonas campestris pv malvacearum,we build a gene knock-out system through the method of homologous recombination.Through a series of phenotype,we preliminarly study clpA gene function.Upstream and downstream fragments of clpA gene were amplified from the Xcm genome and then cloned into PK18 to construct clpA knock-out plasmid.The plasmid was transduced into Xcm wild-type strains by conjugation.after two step homologous recombination,Gene clpA deletion mutant acquired.By comparing knockout strains and wild type strains in heat resistance,resistance to copper ions,ethanol tolerance,salt tolerance ability etc,found that after clp A knocked out,tolerance of strain obviously declined.By comparing colonization and biofilm formation ability of the knockout strains and wild type strains,found that colonization and biofilm formation ability of clpA knockout strains declined.In high salt conditions,compary the knockout strains and wild type strains total protein expression and analyse SDS-PGEA protein electrophoresis,found clp A knockout strains cannot effect the degradation of some proteins,thereby further validation clpA genes associated with adversity stress.The study for clpA provides a scientific and effective prevention and controlling for the Xcm.Also provide a certain help for the further researching clpA gene functions...