目的 通过分析30%聚乙二醇（PEG）模拟的干旱胁迫处理下半夏茎段转录组数据，挖掘响应干旱胁迫的相关基因，探索干旱胁迫下半夏发生"倒苗"的分子机制。方法 以干旱胁迫下半夏发生"倒苗"时的茎段作为研究材料，采用Illumina Hiseq 2500平台进行转录组双向测序，并对数据进行生物信息学相关分析。结果 共获得23.00 Gb clean data，对照组与干旱胁迫处理组分别获得37 467 952和39 903 362个clean reads，经Trinity软件组装获得100 274个uingenes。通过将组装所得unigenes分别与Nr、eggNOG、Pfam、Swiss-Prot、KOG、GO、KEGG、COG等数据库进行比对分析，41 132个unigenes获得功能注释。最终筛选得到差异表达基因4 052个，其中2 080个DEGs表达上调，1 972个DEGs表达下调。KEGG通路富集分析显示，差异表达基因主要集中在核糖体、碳代谢、淀粉和蔗糖代谢、植物激素信号转导和氨基酸生物合成等过程；基因表达水平分析显示，半夏中编码植物激素代谢与信号转导、氧化还原相关酶、热激蛋白和液泡加工酶等基因在干旱胁迫处理后表达水平显著上升，多数编码水通道蛋白的DEGs表达水平下降。结论 通过对PEG模拟的干旱胁迫处理下半夏转录组测序结果进行分析，获得半夏水分代谢、激素代谢与信号转导、相关响应蛋白等候选基因，可为揭示干旱胁迫导致半夏"倒苗"的发生机制提供基因资源和理论依据。

Objective In this study, the transcriptome profile of the stems from Pinellia ternata treated by 30% polyethylene glycol simulated drought stress was analyzed, the key enzyme genes responded to the drought stress were explored, so as to explore the molecular mechanism of P. ternata sprout tumble responded to the drought stress. Methods The stem segments of P. ternata under drought stress were used as research materials. The Illumina Hiseq 2500 platform was applied for transcriptome sequencing, and bioinformatics analysis was performed on the transcriptome data. Results A total of 23.00 Gb clean data was obtained, 37 467 952 and 39 903 362 clean reads were gained from the control groups and the drought stress treatment, respectively, and 100 274 uingenes were assembled by Trinity software. A total of 41 132 unigenes were finally obtained with functional annotations against the Nr, eggNOG, Pfam, Swiss-Prot, KOG, GO, KEGG, and COG databases. Furthermore, 4 052 differentially expressed genes (DEGs) were obtained, in details, 2 080 DEGs were up-regulated while 1 972 DEGs were with down-regulated expression. KEGG Pathway enrichment analysis showed that DEGs were mostly involved in ribosome, carbon metabolism, starch and sucrose metabolism, plant hormone signal transduction and biosynthesis of amino acids process. The expression levels of the genes encoded plant hormone metabolism and signal transduction, redox-related enzymes, heat shock proteins and vacuolar processing enzymes were significantly promoted after drought stress treatment, while most of the DEGs encoded aquaporins were down-regulated. Conclusion By analyzing the transcriptome profiles of P. ternata under drought stress simulated by PEG, the candidate genes associated with water metabolism, plant hormone and signal transduction, as well as the related responsive proteins were obtained, which could provide abundant genetic resources and theoretical basis for understanding the mechanism of P. ternata sprout tumble caused by drought stress.

R282.12

国家自然科学基金资助项目（81703652）；现代农业产业技术体系建设专项资金项目（CARS-21）；陕西省教育厅自然科学专项项目（18JK0223）；咸阳市重大科技专项计划项目（2017k01-26）