Study On Transcriptome And Protein Interaction Network Of Huipizhi Heidou Resistance To Soybean Cyst Nematode

Heterodera glycines(Soybean cyst nematode,SCN)was a serious pathogen in soybean production worldwide.The methods to control this pathogen included physical control,chemical control,biological control,and resistance germplasm application.The lastest was a strategy to inhibit SCN significantly and eco-friendly.Soybena was origined from China,and abundant soybean resources to control SCN.Huipizhi Heidou is an execellent characterization to decrease SCN and be a candidate resource to resistance breeding.For understanding the mechanism of Huipizhi Heidou to resistance SCN,following 5 parts were carried out:1.The Transciptome analysis of Huipizhi Heidou under SCN stress: The Huipizhi Heidou(ZDD2315)and race 3 of Heterodera glycines were chosen to study the mechanism of resistance via examination of transcriptomic changes.After 5,10,and 15 days of SCN infection,whole roots were sampled for RNA extraction,and uninfected samples were simultaneously collected as a control.740,1413,and 4925 genes were isolated by padj(p-value adjusted)<0.05 after 5,10,and 15 days of the infection,respectively,and 225 differentially expressed genes were overlapped at all the time points.We found that the differentially expressed genes(DEGs)at 5,10,and 15 days after infection were involved in various biological function categories;in particular,induced genes were enriched in defense response,hormone mediated signaling process,and response to stress.To verify the pathways observed in the GO and KEGG enrichment results,effects of hormonal signaling in cyst-nematode infection and parasitism(development)were further examined via treatment with,salicylic acid(SA),jasmonic acid(JA),and ethephon,a precursor of ethylene,gibberellic acid(GA),and IAA(indo-3-acetic acid).Firstly,the results indicate that five hormones led to a significant reduction of J2 number in the roots of Huipizhi Heidou and Liaodou15,representing SCN-resistant and susceptible lines,respectively;except the ethephon treated with Liaodou15.Additionally,among the diversity hormones treatment,the development of SCN juveniles was inhibited.Especially,the results showed that the development of SCN was significantly inhibited with IAA treatment;there were 1.58% juvenile fourth stage of SCN in Liaodou15.2.Study on transcriptome and protein interaction network(PIN)of Huipizhi Heidou and Liaodou15 during SCN parasitism: Based on the development of SCN in Huipizhi Heidou and Liaodou15 at 10 days post infection;gene expression of the two soybean cultivars were examined using transcriptome sequencing.The results showed that 4552 and 777 DEGs(differential expressed genes)were identified in Huipizhi Heidou and Liaodou15,respectively(FDR,false discovery rate<0.05).The DEGs(|log2foldchange|>1.50 and FDR<0.05)enrichment was performed via agri GO(http://systemsbiology.cau.edu.cn/agri GOv2/).The enrichment results indicated that the induced DEGs were categorized in response to stress,JA and ET mediated signaling pathways.Furthermore,biological pathways were analyzed and visualized using Mapman between Huipizhi Heidou and Liaodou15.DEGs were enriched in signaling,secondary metabolism,and cell wall metabolism and modification,etc.The proteinprotein interaction networks with 492 and 147 nodes were constructed,respectively;which based on DEGs of two soybean cultivars at 10 day SCN inoculation.The results showed that the nodes with top 10% degree were categorized in protein phosphorylation modification,and the nodes with top 10% degree were enriched in peptide biosynthesis.3.Study on transcriptome and PIN of Huipizhi Heidou and G.soja S54 responsed to SCN infection: The results of transcriptome sequencing analysis indicated that more than 88.57% reads of have mapped in soybean reference genome in S54,a SCN resistance cultivar.The gene differentially analysis showed that 6456 and 4552 differential expressed genes were identified in S54 and Huipizhi Heidou.Furthermore,the DEGs were enriched in response to stress(including oxidative stress and SA),phenylpropanoid and flavone biosynthesis and metabolism process in S54 significantly.The nodes with top 10% degree were enrich in response to strees and carbohydrate biosynthesis and metabolism process.4.The construction of PIN and functional prediction of key nodes in Huipizhi Heidou-SCN interaction: Base on soybean genome-scale PIN(protein interacton network)database,STRING,and transcriptome data of Huipizhi Heidou after SCN infection.PIN including 304,312,and 538 nodes were distributed into three time points after DEGs mapping into soybean STRING dataset,respectively.Functional enrichment showed nodes were categored into protein phosphorylation modification,response to stress,and defense response etc.Furthermore based on go term “response to stress”,the network with 312 nodes and 871 edges was generated and illustrated the interaction relationship among the defense related genes in response to chitin and terpenoid compounds metablisim.Additionally,the results of functional enrichment analysis indicated that the nodes were separated into 10 clusters groups according to Mcode plugin.The nodes clusterss were annotated in response to stress,signaling cascade,and auxin related pathways.5.Network analysis and resistance mechanism exploration of 5 soybean cultivars-SCN interaction: For illuminating the soybean-SCN interaction mechanism,5 protein interaction networks were derived from SCN resistant soybean cultivars(Huipizhi Heidou,Peking,PI88788,PI437654,and PI567516C)response to SCN infection,based on differentially expressed genes mapping to soybean STRING datasets.Among the five soybean cultivars network,862,595,440,280,and 171 nodes were distributed in each network,respectively.During the analysis of nodes and their functional enrichment,the common nodes of Huipizhi Heidou and Peking were annotated in protein phosphorylation process;the nodes of Huipizhi Heidou and PI437654 were categorized in flavone and phenylpropanoid metabolism process.Furthermore,the nodes of PI88788 were involved in cell processes,cell structure,cytoskeleton organization,and the nodes were suppressed during SCN stress.The SCN resistance mechanism of Huipizh Heidou is similar with part of Peking and PI437654 accroding to gene expression and network analysis.