Distribution And Genetic Diversity Of Viral AMGs In The Napahai Plateau Wetland

Viruses are the most abundant organisms on earth and play an important role in microbial community structure and biodiversity by lysing host cells,and can also influence host metabolic pathways through the expression of auxiliary metabolic genes(AMGs),which in turn change microbial community structure and drive biogeochemical cycles.Current reports on AMGs are mainly focused on marine,freshwater lake and rice field environments,while few studies have been reported on plateau wetlands.The Napahai plateau wetland is uniquely located and is unique and seasonal plateau wetlands in China.Therefore,a preliminary study on the distribution and genetic diversity of viral AMGs in the Napahai plateau wetland was carried out.(1)Genetic diversity analysis of viral AMGs in Napahai plateau wetland: phylogenetic analysis with other AMGs from different habitats and different host sources(pho H,pho U,pst S,gnd,zwf,tal C,cob S,maz G and pur M)showed that some sequences of viral AMGs in Napahai plateau wetland was more closely related to those from other different habitats and different host sources.PCo A analysis and α-diversity analysis also demonstrated that the genetic diversity of viral AMGs in Napa highland wetlands was good.(2)Analysis of metabolic pathways involved in viral AMGs: Based on macrogenomic data,pho H,phoU and pstS genes were mainly involved in phosphate metabolic pathways.There are fewer reports for viral AMGs regulating phosphate metabolic pathways.The gnd and zwf genes are involved in the oxidative phase of the pentose phosphate pathway,and tal C gene is involved in the non-oxidative phase of the pentose phosphate pathway.The maz G and pur M genes are involved in the de novo synthesis process of purine nucleotides,and cob S gene is involved in the synthesis process of vitamin B12 coenzyme.Although there are differences in the sequences of the Napahai plateau wetland AMGs compared with other sequences,the metabolic pathways they are involved in and the functions they perform do not differ from those of other habitats or different species of microorganisms.(3)Metabolic flow and AMGs expression analysis of Pseudomonas fluorescens SW-3: The metabolic flow results showed that the addition of phage VSW-3 increased the content of most metabolites detected in the purine nucleotide de novo synthesis pathway,the pentose phosphate pathway,and the interconversion pathway of pentose and glucuronide in the SW-3 strain,and only the content of ribulose 5-phosphate(Ru5P)and ribose5-phosphate(R5P)levels were reduced,which may be used for synthesis of phage nucleic acids.RT-q PCR results showed that pho H,pho U,pst S,gnd,zwf,tal C,cob S,maz G and pur M genes were upregulated when phage was added.Thus,when the zwf gene was upregulated,the amount of metabolite6-phosphogluconate endolipid generated in the pentose phosphate pathway was increased;the pur M gene was upregulated and the amount of metabolite5-aminoimidazole nucleotide generated in the ab initio synthesis of purine nucleotides was increased.When the phage VSW-3 infested the host SW-3,the phage affected the metabolite changes in the host SW-3 by regulating the expression of AMGs to obtain nutrients in the host for its own DNA replication,assembly and release of viral particles and other activities.The results of the study are important for revealing the role of viruses in the biogeochemical cycle of wetland ecosystems.