The Differential Antibacterial Of Senecio Scandens Buch.-ham Based On Transcriptome Sequencing

Objective:Senecio scandens Buch.-Ham is a traditional Chinese herbal medicine,while antibacterial activity is one of the important pharmacological actions,which closely related to the main active components.In this study,we compared the contents,quality,and antibacterial activity of elements in Senecio scandens,and analyzed the mechanism of antibacterial properties of Senecio scandens based on the results of bioinformatics analysis of DEG genes combined with high-throughput transcriptome data.Methods:?1?The bacteriostatic effect of 60%ethanol extract of Senecio scandens aganist 8pathogenic bacteria was verified by plate punch method.The difference of bacteriostatic circle sizes between two Senecio scandens plants were measured and compared.?2?Transcription and sequencing of the whole tissue and organs of the major drug-receiving parts of two plants with different antibacterial traits by Illumina HiSeq^TM 2500 platform.The spliced transcriptome Unigenes is compared to each database for functional annotation analysis.The high-throughput transcriptome second-generation sequencing and third-generation sequencing results are used to screen differentially expressed genes and then the differentially expressed genes are enriched for classification and analysis.Based on the literature,the main metabolic pathways affecting antibacterial ingredients were selected to determine the main components that may affect the antibacterial properties.?3?The total flavonoids were extracted and separated from the two plants of Senecio scandens,detected the kinds and contents by HPLC,verified the antibacterial activity with carring out with antibacterial experiments.Results:1 Screening of antibacterial difference Senecio scandens Buch.-Ham and comparison of main componentsThe 60%ethanol extracts of Senecio scandens 32 and Senecio scandens 35 were resistant to 8 kinds of bacteria,and the inhibition circle of 32 was significantly larger than that of 35,which was the antibacterial material with significant difference.The results of HPLC showed that the UV absorption peaks of the two strains were basically the same,and the peak value of 32 was significantly higher than 35.The content of flavonoids and phenols in Senecio scandens nigrum showed that the content of flavonoids and total phenols in plant 32 was significantly higher than that in plant 35.The content of flavonoids in plant 32 was 64.77 mg/ml,that in plant 35was 32.55 mg/ml,that in plant 32 was 4.172 mg/g,and that in plant 35 was 1.048mg/g.2 Senecio scandens Buch.-Ham antibacterial transcriptome sequencing and analysis A total of 61 171 Unigenes were functionally classified by the GO database,of which there were 17 functional classifications of cellular components,16 functional classifications of molecular functions and 20 functional classifications of biological processes.There were 489 DEGs annotated by KEGG to 50 pathways,of which amino acid biosynthesis was the largest,with 35,followed by 34 carbon metabolisms,26 phenylpropane biosyntheses,25 peroxidases,and plant hormone signals 25transductions.There were 2380 differentially expressed genes were obtained by comparing plants of Senecio scandens 35 with 32 through high-throughput transcriptome equencing datas.Among them,there were 560 up-regulated genes?higher expression level of DEG in plants in 32 than 35?and 1820 down regulated genes?lower expression level of DEG in plants in 32 than 35?.The analysis of the secondary metabolism pathway related to the antibacterial active components showed that the key genes of flavonoid synthesis pathway and phenylpropane metabolism pathway were differentially expressed in the two materials,indicating that the flavonoid compounds and phenolic acids may be closely related to the antibacterial activity of Senecio scandens.3 Antibacterial properties and HPLC analysis of Senecio scandens Buch.-Ham flavonoidsThe results of HPLC analysis of Senecio scandens Buch.-Ham showde that the content of total flavonoids in Senecio scandens extract was compared with that of quercetin and Hyperoside.The results showed that the UV peak area of 32 was higher than that of 35 strain,but there was no significant difference in the UV peak time,which indicating that there was not much difference in the flavone composition but different in quatity between them.Using the Bacteriostatic Experiment of total flavone extract,it was found that the total flavone extract of Senecio scandens had a certain bacteriostatic effect on 8 kinds of tested bacteria,which was lower than that of alcohol extract.Except the E.coli and Salmonella typhimurium,the bacteriostatic effect trends of the other 6 species bacterias were similar with the total alcohol solution.Conclusion:In this study,total flavonoids and total phenolic compounds as the main antibacterial active ingredients of Senecio Scandens in high-antibacterial strain32 was higher than 35.DEG analysis also showed that the expression levels of key genes in the metabolic pathways related to these two types of compounds were higher in plant 32 than 35,suggesting that the antibacterial properties of Senecio scandens are closely related to the content of such compounds.The antifungal effect of flavonoids was not always identical with that of the total alcohol extract,indicating the diversity of antibacterial components and mechanism of action of Senecio Scandens Buch.-Ham..