高抗旱性二倍体马铃薯材料转录组分析及抗旱基因的初步挖掘

Transcriptome Analysis of Diploid Potato Material with High Drought Tolerance and Preliminary Excavation of Drought Resistance Genes

为探究不同干旱胁迫时间处理下,二倍体马铃薯材料对干旱胁迫响应的分子机制,挖掘抗旱相关基因。以高抗旱二倍体资源A90为试验材料,利用转录组测序技术对PEG-6000胁迫下不同时间的差异表达基因进行分析,通过GO富集、KEGG通路分析与转录因子预测参与马铃薯干旱胁迫响应的差异表达基因,初步挖掘抗旱调控关键基因;并通过RT-qPCR对3个抗旱候选基因进行逆境胁迫表达分析。结果表明:A90在20%PEG-6000胁迫处理3,6,24 h与对照相比,共有2519个差异表达基因,这些基因主要富集在植物激素信号转导、谷胱甘肽代谢、苯丙烷生物合成、戊糖和葡萄糖醛酸相互转化等抗旱相关过程中。并且显著富集在通路上的340个共差异表达基因中有53个基因注释到了RLKs、AP2/ERF和Tify等15个转录因子家族中,其中StST/K1、StERF1和StTify1的表达量较高,有可能是抗旱调控关键基因。基因StST/K1和StERF1受到干旱和低温胁迫主要在材料的根和叶中上调表达,基因StERF1在盐胁迫下在材料的根、茎和叶中均上调表达;基因StTify1在受到干旱在材料的茎和叶中上调表达,受到盐胁迫在材料的根、茎和叶中均上调表达,但在低温胁迫下只在材料的茎中下调表达。由此说明,筛选出的3个基因均能够对干旱、盐和低温胁迫产生响应,可为今后马铃薯抗旱分子育种中相关抗旱候选基因研究提供一定的理论基础。

In order to explore the molecular mechanism of diploid potato material response to drought stress under different drought stress time treatment,and explore drought resistance related genes.The high drought-resistant diploid resource A90 was used as experimental material,and transcriptome sequencing technology was used to analyze the differentially expressed genes under PEG-6000 stress at different times.Differentially expressed genes involved in drought stress response of potato were predicted by GO enrichment,KEGG pathway analysis and transcription factors,and key genes of drought resistance regulation were preliminarily explored.The expression of three candidate genes was analyzed by RT-qPCR.The results showed that there were 2519 differentially expressed genes in the A90 treated with 20%PEG-6000 for 3,6,24 h compared with the control,and these genes were mainly enriched in plant hormone signal transduction,glutathione metabolism,phenylpropanoid biosynthesis,pentose and glucuronate interconversions and other drought-related processes.In addition,among 340 codifferentially expressed genes significantly enriched in the pathway,53 genes were annotated to 15 transcription factor families including RLKs,AP2/ERF and Tify.Among which StST/K1,StERF1 and StTify1 had higher expression levels,which might be key genes in drought resistance regulation.StST/K1 and StERF1 were mainly up-regulated in roots and leaves under drought and low temperature stress,StERF1 was up-regulated in roots,stems and leaves under salt stress.StTify1 was up-regulated in stems and leaves of the material under drought,and it was up-regulated in roots,stems and leaves under salt stress.But it was down-regulated only in stems of the material under low temperature stress.These results indicate that the three selected genes can respond to drought,salt and low temperature stress,it can provide a theoretical basis for study on drought resistance candidate genes in potato molecular breeding in the future.