Peanut is an important crash crop worldwide, and it is often threatened by drought stress due to unexpected extreme weather events. In this work, NH5 and FH18 were selected as drought-tolerant and drought-sensitive varieties, respectively. Comparison of their physiological responses revealed that NH5 showed less wilting, higher relative water content and lower water loss rate of detached leaves, lower electrolyte leakage, and stronger antioxidant ability under drought stress than did FH18. Based on comparative transcriptomic analysis, 5376 differentially expressed mRNAs were commonly identified in the two varieties, and 2993 genes specifically changed in the drought-tolerant variety and were mainly enriched in photosynthesis-antenna proteins and photosynthetic pathways. Furthermore, 73 microRNAs (miRNAs) were differentially expressed in the drought tolerance variety specifically under drought stress; of these, two key candidate miRNAs, novel miR_416 and novel miR_73, were identified, and the majority of their target genes were enriched in phenylpropanoid biosynthesis, linoleic acid metabolism, and cutin, suberine, and wax biosynthesis. This study lays the foundation for the analysis of the molecular mechanism of drought tolerance and promotes the genetic improvement of peanut drought tolerance.

中文翻译：

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全基因组鉴定与花生耐旱性相关的关键候选微小RNA和靶基因

花生是世界范围内重要的农作物，由于意外的极端天气事件，经常受到干旱胁迫的威胁。在这项工作中，分别选择了NH5和FH18作为耐旱品种和干旱敏感品种。比较它们的生理反应表明，与FH18相比，NH5在干旱胁迫下表现出更少的枯萎，较高的相对水分含量和较低的离叶失水率，较低的电解质泄漏以及更强的抗氧化能力。基于比较转录组学分析，在两个品种中通常鉴定出5376个差异表达的mRNA，在耐旱品种中特异地改变了2993个基因，并且主要富含光合作用-天线蛋白和光合作用途径。此外，73个microRNA（miRNA）在耐旱品种中特别是在干旱胁迫下差异表达；其中，鉴定了两个关键的候选miRNA，即新颖的miR_416和新颖的miR_73，它们的大多数靶基因富含苯丙烷类生物合成，亚油酸代谢以及角质，地下和蜡生物合成。本研究为分析抗旱性的分子机理奠定了基础，并促进了花生抗旱性的遗传改良。