Transcriptional Sequencing?Assembly And Analysis Of Dianthus Chinensis L.Seedlings In Response To Short Time Salt-stress

Salt stress is one of significant adversity hazards for plant growth.The studies on mechanisms of salt resistance in plant are necessary for plant improvement and cultivation in saline soil.Dianthus Chinensis L is an ornamental plant of salt-tolerance,which was used as materials in this study.Its seedings were treated in 100 mM NaCl for 0,1,3,6h and then were removed from salt stress for 1 and 3h.After that leaves and roots were collected to extract total RNA,which was used for the transcriptome sequencing,assembly and analysis.The aim of our study was to further elucidate the mechanism of salt tolerance in Dianthus Chinensis L on the level of gene expression and to obtain the salt resistant genes for improvement of new varieties in Dianthus.Research results were as follows:1.After the sequencing and assembly we obtained 62371 unigenes,and 31863(51.08%)of them were annotated.There were 22662 unigenes in 46 GO terms,11810 unigenes in26 KOG groups,and 10265 unigenes predicted 272 pathways by the KEGG annotation.2.There were 6564 and 12195 salt-induced genes in leaf and root respectively under salt stress.Compared with DEGs in leaf under salt stress for 1?3 and 6h the DEGs in root were 19.90,1.25,and 2.6 times at the same time.Based on GO enrichment analysis the salt-induced genes were mainly enriched in the cellulose metabolism in root and were enriched in the transcription and translation process in leaf,respectively.Based on the KEGG analysis the pathways were e firstly involved in signal substance which influenced sugar metabolism,fat metabolism and styrene acrylic pigment metabolism salt stress.Signal substance in leaf were produced under salt stress for 6h,which were postponed compared with the root.3.The salt-induced genes involved in redox reaction and cell oxidation reduction balance of BP in GO enrichment were selected.By RT-PCR the expression levels of DchAAO1 and DchPOD1 in leaf and of DchAAO2?DchPOD2 in root were decreased under salt stress,but were increased after the stress were removed.And the expression levels of DchTrx in leaf and of DchGrx1?DchGrx2?DchTrx in root were increased under short time salt-stress,but were decreased after the stress were removed.The expression patterns of the selected genes met with the RNA-Seq data,which meant our results were reliable.4.We studied the expression patterns under the salt stress with prolonged time in Dianthus Chinensis L seedlings.The results showed that the expression levels of DchAAO1,DchPOD1 and DchTrx decreased from 9 to 12 h and then kept stable after 12 h in leaf.Moreover,the gene expression levels under the same time were lower than their individual controls in leaf under salt stress.The expression levels of DchPOD2 had little change under stress extension,but compared to their individual controls under 12 and 24 h its expression levels decreased.The expression levels of DchAA02 increased from 9 to 12 h and then dropped after 12 h.Its expression levels increased compared to their individual controls under 12 and 24 h.The expression levels of DchGrxl and DchGrx2 increased from 9 to 12 h and then dropped after 12 h.Their expression levels were higher than their individual controls under 9 and 12 h,but lower than their individual controls after 12 h.The expression levels of DchTrx rose firstly and then dropped.However,its gene expression levels were lower than its controls under the same time of salt stress.