Study On Differential Proteomics Of Pathogenicity And Development Of Metarhizium Anisopliae

Metarhizium anisopliae is an entomopathogenic fungus that plays an importantrole in agricultural pest prevention and disease vector control. Its conidia and myceliaare closely related to fungal propagation and also are responsible for host infection.Despite of their importance, the aspect of proteomics research is still limited.In order to investigate protein differential expression profiling and search forproteins which are related with pathogenesis mechanism in conidia and mycelia of M.anisopliae, comparative proteomic analysis was performed using two-dimensional gelelectrophoresis(2-DE)and matrix-assisted laser desorption ionization/time-of-flight(MALDI-TOF)/mass spectrometry. In our study, A total of898±37and1072±24protein spots were detected in conidia and mycelia of high virulentstrain(Ma1291),respectively. A total of757±28and1061±32protein spots weredetected respectively in conidia and mycelia of weak virulent strain(Ma20). In all130differential expression protein spots(75from conidia,55from mycelia)were identifiedby MALDI-TOF/MS, and there were97protein spots(43from conidia,54frommycelia)were successfully identified. Most identified protein spots were distributedfrom20kDa to80kDa in mass range and between5and9of calculated pI.Compared with Ma1291mycelia, there were nine successful identified proteinspots in conidia which were up-regulated in expression, and four successfullyidentified proteins belonging to conidia specifically. Meanwhile, there were sixsuccessfully identified and up-regulated protein spots in mycelia, four were peculiarfor mycelia. Compared with Ma20mycelia, there were only three protein spotssuccessfully identified and up-regulated, and only two were exclusive to conidia. Andthere were twenty-seven protein spots successfully identified and up-regulated, sevenof which were specific for mycelia. Compared with Ma20conidia, there were tenprotein spots successfully identified and up-regulated, and ten of which are proper forMa1291conidia. There were only three protein spots successfully identified andup-regulated, only two of which were owned specially by Ma20conidia. Comparedwith Ma1291mycelia, there were ten successfully identified protein spots that were up-regulated in Ma20mycelia.In Ma1291conidia, one of up-regulated proteins is glutathione S-transferase II,which is able to help eliminate reactive oxygen species and protect cell proteins fromoxidative damage. In addition, we also identified the heat shock protein90being ableto protect cell and response to various external stress, which can make conidia livebetter.20S proteasome subunit can help form appressorium. And in mycelia, theywere many up-regulated proteins which are involved in biosynthesis and material andenergy metabolism. We found that heat shock protein70was up-regulated, which canhelp the protein transport between cells and participate in protein folding, and so on.Additionally, there was catalase in the mycelia, which can also help clear the reactiveoxygen species in cells and protect protein in vivo.In Ma20conidia, CBR-PRO-3protein was up-regulated, playing an importantrole in removing toxic effects of exogenous compounds. Most of the up-regulatedproteins were detected in Ma20mycelia and they take part in various biosynthesis andmaterial and energy metabolic pathways. The peroxiredoxin is important because itcan protect mycelial cell from oxidative stress.Compared with Ma20conidia, heat shock protein60was up-regulated inMa1291conidia, which is the most conservatively defensive in cells and can helpenhance virulence of strain. Moreover, we also found that the protein synthesis andthe ability of transportation material were both increased, which indicated that it isbetter to cope with the stimulation of external pressure. Protease is exclusive to theMa1291conidia, which is related with virulence and plays a crucial role in theprocess of M. anisopliae invading insect. While in Ma20we only found proteinswhich ars related with material and energy metabolism. Between Ma1291myceliaand Ma20mycelia, we didn't identiy any proteins involved in virulence or resistance.