水分胁迫下马铃薯萌芽出苗期根系转录组差异表达分析

Transcriptome of potato seedling roots to water stress

以马铃薯‘克新1号’为材料,通过Illumina HiSeqTM 4000高通量测序技术,对不同水分胁迫后的马铃薯萌芽出苗期根系cDNA文库进行了RNA-Seq分析,拟探明马铃薯感应水分胁迫的分子机制,挖掘出与抗旱密切相关的功能基因.将比对到基因组上的基因利用RPKM衡量各样本间的基因表达丰度,以P<0.05筛选出差异表达基因,通过GO(基因本体,gene ontology)数据库、KEGG代谢途径数据库,对不同水分胁迫样本差异表达基因的功能和参与的调控路径进行分析;选择6个差异表达基因,利用实时荧光定量PCR验证RNA-Seq结果的可靠性.结果表明:(1)DLWR(重度水分胁迫)样本中,比对到基因组的表达基因30114133个,差异表达基因5241个;LWR(中度水分胁迫)样本中,比对到基因组的表达基因32858890个,差异表达基因1488个.2个样本中同时存在的差异基因369个,其中上调表达基因78个,下调表达基因291个;显著差异表达基因主要与蛋白激酶、水解酶、氧化还原酶、水通道蛋白、转运蛋白、转录因子等相关.(2)在GO富集分析中,2个水分胁迫处理样本在生物学功能中富集的类别并不完全相同,但显著富集的主要是与氧化还原、转运、膜结合、转录调节子等相关的基因.(3)KEGG代谢分析显示,差异表达基因显著富集在谷胱甘肽代谢、植物激素信号转导等途径,与植物抗逆能力密切相关.(4)利用qRT-PCR验证的6个基因表达模式与RNA-Seq分析结果一致,证实了RNA-Seq结果的可靠性.通过研究得到了不同水分胁迫下马铃薯根系转录组信息,获得了差异基因及其功能信息,阐明了差异基因所参与的代谢通路及与植物水分胁迫的关系.

In this study,a variety‘KEXIN 1’was used to analyse root cDNA library of potato treated with water stress by Illumina HiSeqTM 4000,to understand the inner molecular mechanisms of potato in response to water stress,and mine these genes closely related to drought tolerance.then the abundance of gene expression among different samples were screened according to transcriptome data by using RPKM method,and the differentially expressed genes among the samples were estimated by referring to the stand ard of P<0.05,Function and pathway of those different expression were investigated using Gene Ontology(GO)database and KEGG pathway database,the qRT-PCR assays were implemented to verify the expression pattems of six genes,respectively.The results showed that:(1)Total 30114133 expressing genes were got in DLWR,different expression genes were 5241,32858890 expressing genes were got in LWR,different expression genes were 1488,there were 369 differentially expressed genes in two samples,including 78 up-regulated genes and 291 down-regulated genes,significantly different expression genes mainly involved inprotein kinase,hydrolase,oxidoreductase,aquaporin,transporter,transcription factors and so on.(2)GO enrichment analysis showed that some differences in the biological functions existed among the treated samples,but significantly enriched mainly with redox,transport,membrane binding,transcriptional regulators and other related genes.(3)The KEGG pathway analysis indicated differentially expressed genes significantly enriched in glutathione metabolism,plant hormone signal transduction and other pathways,and plants are closely related to resilience.(4)The results of qRT-PCR analysis of six differe-ntially expressed genes were consistent with those of RNA-Seq data,further confirming the reliability of RNA-Seq results.Through the research,got the information of root transcriptome of potato under different water stress,got the differentially expressed genes and their function information,explain the metabolic pathways involved in differential genes and their relationship with plant water stress.