马铃薯块茎膨大期叶片响应干旱与复水的转录组分析

Transcriptome Analysis of Leaf Response to Drought and Rehydration in Potato Tuber during Bulking Stage

以榆林市农科所提供的‘冀张薯8号’组培苗为试验材料,在马铃薯对水分比较敏感的块茎膨大期进行干旱与复水处理,利用RNA-seq技术分析马铃薯叶片在干旱胁迫和水分刺激下的基因表达谱,采用q-RT-PCR技术验证RNA-seq数据的可靠性。结果表明:随机选取的16个基因与转录组数据高度一致,进一步证明转录组数据的可靠性。在分子水平上,水分胁迫使马铃薯叶片中基因表达大幅调整,与ABA及环境胁迫诱导的基因、膜脂代谢相关基因大幅上调,复水后快速恢复。经KEGG富集分析,水分胁迫下叶片差异表达基因主要富集于次生代谢生物合成途径、植物激素信号转导、淀粉和蔗糖代谢等过程。复水后,与蛋白质合成、转录调控、吸水能力和有毒物质清除有关的基因大幅上调表达,以适应马铃薯干旱后复水的快速恢复以及补偿生长的要求。研究结果可为抗旱抗逆性的品种改良提供基因资源,同时为深层次揭示马铃薯抗旱机理提供理论基础。

This study using the tissue cultured plantlets of potato variety‘Jizhangshu No 8’provided by Yulin Institute of Agricultural Sciences as the test material,drought and rehydration were imposed during the tuber expansion stage,which is the potato moisture sensitive period,and RNA-seq was employed to analyze gene expression profiles under drought stress and water stimulation,and q-RT-PCR was used to validate the reliability of RNA-seq data.The results showed that the expression levels of 16 randomly screened genes were highly consistent with the transcriptome data,further verifying the reliability of the transcriptome data.At the molecular level,water stress greatly regulated gene expression in potato leaves,genes related to ABA and environmental stress and membrane lipid metabolism were significantly upregulated and recovered quickly after rehydration.By KEGG enrichment analysis,leaf differential expression genes under water stress were mainly enriched in the secondary metabolic biosynthesis pathway,phytohormone signaling transduction,and starch and sucrose metabolism pathway.After rehydration,genes related to protein synthesis,transcription regulation,water absorption capacity adjustment,and toxic substance scavenging were greatly upregulated,which accommodated the rapid recovery of potato under rehydration after drought and the requirements of compensating for growth.The results of this experiment can provide gene resources for the improvement of drought resistance varieties,and provide a theoretical basis for further revealing the mechanism of potato drought resistance.