BACKGROUND Both drought and heat stress are serious global problems, leading to agricultural production loss. MicroRNAs (miRNAs) play important roles in plant species responding to individual drought and heat stress. However, the miRNAs and mRNAs in association with combined drought and heat in crops like tomato remains unclear. RESULTS We studied the crosstalk of miRNAs and their target genes in tomato plants grown under simultaneous drought and heat stress that frequently happen in field conditions. In total, 335 known miRNAs representing 55 miRNA families and 430 potential novel miRNAs were identified in Solanum lycopersicum L. using small RNA deep sequencing. Through expression analysis, miRNAs in association with drought, heat and the combination of these were investigated. In total, 61, 74 and 37 miRNAs were differentially regulated for combination (of both stresses) vs control, combination vs drought and combination vs heat, respectively. Target genes with different expression levels were found using degradome sequencing, which were mainly involved in transcription factor activity, sequence-specific DNA binding, transcription, regulation of transcription, nucleus, DNA binding etc. The quantitative real-time polymerase chain reaction (qRT-PCR) results confirmed the accuracy of sequencing. CONCLUSIONS Our study serves as valuable knowledge on how crop adapted to combined drought and heat stress by regulating miRNAs and mRNAs, which provide information for crop improvement to deal with future climate changes.

中文翻译：

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番茄叶片中独特的miRNA及其靶标对干旱和热胁迫的综合响应。

背景技术干旱和热胁迫都是严重的全球性问题，导致农业生产损失。微小RNA（miRNA）在植物物种对单个干旱和高温胁迫的响应中起着重要作用。然而，与诸如干旱和高温的番茄等作物相关的miRNA和mRNA尚不清楚。结果我们研究了在田间条件下经常发生的干旱和高温胁迫下生长的番茄植物中miRNA及其靶基因的串扰。总计，使用小RNA深度测序在茄果茄中鉴定了代表55个miRNA家族的335个已知miRNA和430个潜在的新颖miRNA。通过表达分析，研究了与干旱，高温以及它们的组合相关的miRNA。总共61 分别针对（两种胁迫）组合与对照，组合与干旱以及组合与热对74和37个miRNA进行了差异调节。使用降解基因组测序发现了具有不同表达水平的靶基因，这些基因主要涉及转录因子活性，序列特异性DNA结合，转录，转录调控，细胞核，DNA结合等。定量实时聚合酶链反应（qRT- PCR）结果证实了测序的准确性。结论我们的研究提供有价值的知识，帮助人们了解如何通过调控miRNA和mRNA来适应干旱和热胁迫的结合，从而为改良作物以应对未来的气候变化提供信息。使用降解基因组测序发现了不同表达水平的靶基因，这些基因主要涉及转录因子活性，序列特异性DNA结合，转录，转录调控，细胞核，DNA结合等。定量实时聚合酶链反应（qRT- PCR）结果证实了测序的准确性。结论我们的研究提供有价值的知识，帮助人们了解如何通过调控miRNA和mRNA来适应干旱和热胁迫的结合，从而为改良作物以应对未来的气候变化提供信息。使用降解基因组测序发现了不同表达水平的靶基因，这些基因主要涉及转录因子活性，序列特异性DNA结合，转录，转录调控，细胞核，DNA结合等。定量实时聚合酶链反应（qRT- PCR）结果证实了测序的准确性。结论我们的研究提供有价值的知识，帮助人们了解如何通过调控miRNA和mRNA来适应干旱和热胁迫的结合，从而为改良作物以应对未来的气候变化提供信息。实时定量聚合酶链反应（qRT-PCR）结果证实了测序的准确性。结论我们的研究提供了有价值的知识，帮助人们了解如何通过调节miRNA和mRNA来适应干旱和热胁迫的结合，从而为作物改良以应对未来的气候变化提供信息。实时定量聚合酶链反应（qRT-PCR）结果证实了测序的准确性。结论我们的研究提供有价值的知识，帮助人们了解如何通过调控miRNA和mRNA来适应干旱和热胁迫的结合，从而为改良作物以应对未来的气候变化提供信息。