多花黄精种子萌发前后基因表达特征分析

Analysis of gene expression characteristics before and after seed germination of Polygonatum cyrtonema

多花黄精种子具有综合休眠现象,解析其种子萌发前后基因表达的变化,对探讨种子生理、打破休眠等具有重要作用。该研究基于高通量Illumina HiSeq 2500测序技术,对萌发过程的4个阶段进行转录组测序及生物信息学分析,剖析萌发前后差异基因表达特征。结果表明:(1)通过de novo组装,分别获得388231个Transcripts和178319个Unigenes。(2)萌发前后显著性差异表达的Unigenes有11817个,其中上调的有6405个,下调的有5412个。(3)GO富集分析表明,上调与下调的差异基因均主要富集在生物过程和分子功能中,主要参与代谢过程、催化活性等。(4)KEGG富集分析表明,差异基因主要富集于核糖体、植物激素信号转导、淀粉和蔗糖代谢等通路中;上调的差异基因中富集在核糖体231个、植物激素信号转导56个、淀粉和蔗糖代谢76个,下调的差异基因中富集在苯丙烷生物合成48个、植物激素信号转导48个、淀粉和蔗糖代谢48个;40个差异基因参与了生长素通路中关键酶的合成;淀粉和蔗糖代谢通路中,编码蔗糖磷酸合酶等基因下调,而编码糖原磷酸化酶等基因则上调。该研究结果初步明确了植物激素信号转导与淀粉和蔗糖代谢在多花黄精种子萌发前后起着关键作用,并阐明了这两条通路上参与的关键基因,为多花黄精种子的生理、繁殖及育种等深入研究提供了参考。

Polygonatum cyrtonema seeds have a comprehensive dormancy phenomenon,and analyzing the changes of key genes before and after seeds germination plays an important role in exploring seed physiology and breaking dormancy.Based on high-throughput sequencing technology(Illumina HiSeq 2500),the transcriptome sequencing and bioinformatics analysis were carried out in four stages of P.cyrtonema seed germination with three biological replicates.The results were as follows:(1)A total of 388231 Transcripts and 178319 Unigenes were obtained by de novo assembly.(2)Among the 11817 Unigenes with significant differences before and after germination,6405 were up-regulated and 5412 were down-regulated.(3)Significant difference genes were enriched and analyzed in the GO enrichment analysis,and the differential expression up-and down-regulation Uningenes were main enriched in biological process and molecular function,which were mainly involved in metabolic processes and catalytic activities.(4)KEGG significant enrichment indicated that the differential expression genes were mainly enriched in ribosome,plant hormone signal transduction,starch and sucrose metabolism and other pathways;the up-regulated differential genes were mainly enriched in ribosome 231,plant hormone signal transduction 56,starch and sucrose metabolism 76 and others;the down-regulated differential genes were mainly enriched in phenylpropanoid biosynthesis 48 plant hormone signal transduction 48,starch and sucrose metabolism 48,and other pathways;a total of 40 differential genes were involved in the synthesis of auxin pathway key enzymes.Genes encoding sucrose phosphate synthase were down-regulated and genes encoding glycogen phosphorylase were up-regulated in starch and sucrose metabolic pathways.The above results preliminarily identify that plant hormone signal transduction and starch and sucrose metabolism play a key role before and after the germination of P.cyrtonema seeds,and clarify the key genes involved in these two pathways,which provide a reference for further research on the physiology,reproduction and breeding of P.cyrtonema seeds.