千里光茎和叶的差异表达基因分析

Analysis on differentially expressed genes in stem and leaf of Senecio scandens

以千里光(Senecio scandens Buch.-Ham. ex D. Don)强抗菌性植株SC-32为研究对象,分别提取其茎和叶的总RNA,经质量检测合格后构建cDNA文库,利用Illumina HiSeq^(TM) 2500高通量测序平台对千里光茎和叶的cDNA文库进行转录组测序,筛选差异表达基因,并运用Nr、Swiss-Prot、KEGG和COG数据库对差异表达基因进行功能分析。结果表明:从千里光茎和叶的cDNA文库中分别获得26 147 016和26 996 119个clean reads,Q30值分别为95.17%和94.74%,说明其转录组测序结果良好。从千里光的茎和叶中共筛选到10 991个差异表达基因,以茎中差异表达基因的表达量为准,叶中上调的差异表达基因有5 542个,下调的差异表达基因有5 449个。千里光的茎和叶中共有7 683个差异表达基因被GO功能注释成生物过程、细胞组分和分子功能3个大类53个亚类,且这些差异表达基因与信号传导途径、次生代谢过程、细胞组分合成和酶催化活性等密切相关。KEGG代谢通路分析结果表明:共有4 527个差异表达基因,涉及50个代谢通路,主要参与碳代谢、氨基酸生物合成及淀粉和蔗糖代谢。研究结果显示:千里光茎和叶的差异表达基因具有器官特异性,并且,其茎和叶的分化和形成与多糖和蛋白质累积密切相关。

Taking strong anti-microbial plant SC-32 of Senecio scandens Buch.-Ham.ex D.Don as research object,total RNA from its stem and leaf was extracted,respectively,and cDNA library was constructed after qualified by quality test.Transcriptome sequencing of cDNA libraries of stem and leaf of S.scandens was conducted by using Illumina HiSeqTM 2500 high-throughput sequencing platform,the differentially expressed genes were screened,and their functional analyses were conducted by using Nr,Swiss-Prot,KEGG,and COG databases.The results show that 26 147 016 and 26 996 119 clean reads are obtained from cDNA libraries of stem and leaf of S.scandens,and their Q30 values are 95.17%and 94.74%,respectively,indicating that its transcriptome sequencing result is fine.10 991 differentially expressed genes are totally screened from stem and leaf of S.scandens.Taking expression level of differentially expressed gene in stem as standard,there are 5 542 up-regulated differentially expressed genes and 5 449 down-regulated differentially expressed genes in leaf.7 683 differentially expressed genes in stem and leaf of S.scandens are totally annotated by GO function into 53 sub-categories of 3 major categories(including biological process,cellular component,and molecular function),and these differentially expressed genes are closely related with signal transduction pathway,secondary metabolic process,cell component synthesis,and enzyme catalyze activity,etc.The analysis result of KEGG metabolic pathway shows that there are 4 527 differentially expressed genes,which relate to 50 metabolic pathways,and mainly involve in carbon metabolism,biosynthesis of amino acids,and starch and sucrose metabolism.It is suggested that differentially expressed genes in stem and leaf of S.scandens have organ specificity,and the differentiation and formation of stem and leaf are closely related with accumulations of polysaccharide and protein.