Research On Anti-chromium Mechanism Of Marine Penicillium Janthinellum P1 Based On Transcriptome Sequencing

As we all know,the heavy metal ion chromium is toxic.When it is released into the environment in large quantities,it will pose a threat to life systems.Metal pollution is a common problem.Bioremediation technology was not applied to the treatment of metal pollution until the 1980 s.Compared with traditional remediation methods,bioremediation methods have been studied due to low economic investment and environmental pollution.Wide attention of personnel.In the past millennia,in-depth research has been conducted on marine fungi,and considerable progress has been made in their phylogeny,biodiversity,and heavy metal resistance.Compared with terrestrial fungi,marine fungi generally have the advantages of salt tolerance,low temperature resistance,high pressure resistance,strong UV exposure,high permeability,and heavy metal resistance.This thesis takes the marine fungus Penicillium janthinellum P1,which is highly resistant to heavy metal chromium,as the research object.First,the change trend of a series of physiological and biochemical indicators of the P1 strain when the Cr concentration is 0 M and 1 M is explored.Secondly,on the basis of physiological and biochemical research,Illumina-Hiseq technology is used for transcriptome sequencing.The original data is filtered through quality control and assembled by de novo to obtain a relatively complete transcript,and then combined with Nr,KEGG,GO,KOG and Swiss-Prot performs gene annotation,analyzes gene function and metabolic pathways;uses |log2(FC)|>2,P value<0.01 as the standard to screen differentially expressed genes under stress of different Cr concentrations;uses WGCNA network co-expression analysis strategy to further Identify Hub genes that may be related to chromium resistance.Finally,fluorescence quantitative PCR was used to verify some core genes.Through the above research,the following results are obtained:(1)ROS of P1 strain increases with time,and its content will increase under chromium stress conditions.Its content changes with the activity of antioxidant enzymes,SOD,POD,CAT and the content of MDA in the cell.Link.(2)The study on the assembly of the transcriptome of the P1 strain showed that: 12 c DNA libraries were created,and 53.33 GB of effective sequences were obtained.After de novo assembly,21190 Unigenes were obtained,of which Contig N50 was 4187 kbp and GC content was 47.64%.(3)The research on the transcriptome analysis of the P1 strain showed that the transcripts were compared with the five main databases of Nr,KEGG,Swiss-Prot,KOG and GO,showing that the most annotated genes in the Nr database were 14,769,accounting for 69.7%,followed by KEGG,with 12,000,accounting for 56.6%.A total of 12352 coding protein regions were predicted.DESeq2 analyzed 6655 differentially expressed genes,of which 4234 were up-regulated genes and 2421 were down-regulated genes.(4)Research on the WGCNA analysis of the transcriptome data of P1 strains showed that:through further analysis of the transcriptome data network,the gene cluster was divided into19 modules,combined with the results of physiological and biochemical experiments,related to 6 traits,and the most relevant was selected The network diagram was constructed by 3modules,and 52 core genes were found.In order to verify the accuracy of transcriptome sequencing data analysis,10 possible core genes related to chromium resistance were selected and verified by real-time fluorescent quantitative PCR.The results were in line with the expected experimental assumptions.The above-mentioned research work fills the gaps in the research of Penicillium janthinellum P1 transcriptome,and lays a theoretical foundation for further mining and utilization of P1 high resistance to heavy metal chromium.