Transcriptome Analysis Of Sorghum Dochna(LT-1) Under Water Stress

Water shortage is one of the main factors that restrict the agricultural production.Correspondingly,soil moisture affects plant's physiological and ecological characteristics and the growth processes,because drought damage to plants has exceeded the total of all other adversity-stress factors.When plants suffer drought,they regulate the genes expression in cellular and produce new proteins through the perception and transduction of drought signals,which cause a large number of physiological and metabolic changes.Therefore,with the increasing water resources crisis and the drought hazards,how to better adapt drought has become one of the important topics in global research [1].At present,both domestic and foreign researches on drought stress only concentrate on economic crops such as wheat,corn,and sorghum dochna,but for energy crops like sorghum dochna,studies of drought resistance level focused more on physiological and biochemical aspects.Analysis of transcriptome's drought stress level also has not been reported so far.China is a country which short of water resources,so it is of great significance to carry out research on crop drought resistance.In this paper,Liao Tian 1,(known as LT-1,one of the Sorghum dochna),was used as the experimental material.By simulating drought stress,a transcript libraries of Sorghum dochna transcriptome was constructed using high-throughput sequencing technology.COG annotation classification,GO enrichment analysis,and KEGG pathway enrichment analysis were performed to identify the differentially expressed genes,the metabolic pathways responding to drought stress,and the molecular regulation mechanism of drought resistance in Sorghum dochna seedlings,which elucidated and found the response to drought stress based on related genes and proteins.Details of my findings are as follows:(1)High-throughput sequencing was sequenced by HiSeq2500 pair-end sequencing(PE).A total of 17.34 Gb clean data was obtained from two samples.The clean data of each sample reached 8.58 Gb,Q30 Base percentage reached to 91.09%.(2)135,265 Unigenes were obtained after assembly,and there are 13,674 Unigenes with a length of more than 1 kb.We compared the samples using the NR,Swiss-Prot,KEGG,COG,KOG,GO,and Pfam databases,functional annotation was carried out in Unigenes and obtained a total of 31,316 Unigenes annotation results.(3)CDS prediction and SNP analysis were conducted and through gene structure analyze by SSR,we got 5656 labeled genes in Unigene library.(4)We analyzed the gene expression level of T01(control)and T02(treatment group),1979 differentially expressed genes were identified,among which 1065 were up-regulated and 914 were down-regulated.(5)NR,Swiss-Prot,KEGG,COG,KOG,GO,and Pfam databases were used for comparison,through the database comparison,annotate genes with different expressions pattern clustering and enrichment analysis,totally found 1698 differences genes,of which the most annotated database was nr and the number was 1691.The KEGG database maps a total of 495 differentially expressed genes,which are the targets of our lab data.(6)Another finding is that when Sorghum dochna is under drought stress,plant hormone signal transduction and amino sugar and nucleotide sugar metabolism or tyrosine metabolism pathways have a good correlation with the drought stress response of Sorghum dochna,so we will focus these three pathways in the following research.(7)After comparing the transcriptome data with the GO database,we found that the Sorghum dochna seedlings were enriched in the following process under drought stress.Among the major categories of biological processes(BP)are: hormone synthesis and signal transduction process,translation response process,salt stress response process,cadmium ion response process,cold stress response process,bacterial defense reaction,photorespiration;the major of cellular components(CC)classifications include: cytosol,chloroplast,chloroplast matrix,nucleoli,chloroplast envelope;and the molecular function(MF)classification including ribosome structural components,chitinase activity,sequence-specific DNA binding transcription factor activity.In this experiment,high-throughput sequencing was used to analyze the transcriptome and different genes expression,which greatly enriched the transcriptome data resources of Sorghum dochna and laid a foundation for the study of the molecular mechanism of response to drought stress in Sorghum dochna.