MicroRNAs (miRNAs) are a class of small endogenous non-coding RNAs that direct post-transcriptional gene silencing. In plants, numerous miRNAs have been demonstrated to be regulated under drought-induced stress. However, the role of miRNAs in drought regulation remains unclear in potato. In this work, the function of stu-miR159a was investigated in responding to drought stress in potato. Upon examination, StGAMyb-like1 was identified as the target gene for stu-miR159a. Overexpression of stu-miR159a (stu-miR159a OE plants) increased sensitivity to drought, interference with stu-miR159a activity by target mimics (stu-miR159a ST plants) resulted in drought resistance. During drought treatment, the target gene StGAMyb-like1 showed increased activation in stu-miR159a ST plants compared to non-transgenic plants. In contrast, drought stress induced weaker activation of the target gene in stu-miR159a OE plants. In stu-miR159a ST plants, the expression of critical genes in the anthocyanin biosynthesis pathway (StF3′5′H, StF3′H and StCHS2) was increased by decreasing stu-miR159a activity and simultaneously increasing that of StGAMyb-like1. Meanwhile, with drought treatment, stu-miR159a ST plants exhibited higher anthocyanin accumulation than non-transgenic ones, indicating enhanced antioxidant capacity and improved drought tolerance. The above data support that stu-miR159a is a negative regulator of drought stress and provide new insights into the stu-miR159a-mediated regulation of the anthocyanin biosynthesis pathway in controlling drought tolerance in potato.

中文翻译：

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stu-miR159a 负调控花青素特异性 MYB 转录因子介导马铃薯耐旱胁迫


MicroRNA （miRNA） 是一类指导转录后基因沉默的小型内源性非编码 RNA。在植物中，许多 miRNA 已被证明在干旱诱导的胁迫下受到调节。然而，miRNAs 在马铃薯中干旱调节中的作用仍不清楚。在这项工作中，研究了 stu-miR159a 在响应马铃薯干旱胁迫中的功能。经检查，StGAMyb-like1 被鉴定为 stu-miR159a 的靶基因。过表达 stu-miR159a （stu-miR159a OE 植物） 增加了对干旱的敏感性，目标模拟物 （stu-miR159a ST 植物） 对 stu-miR159a 活性的干扰导致抗旱性。在干旱处理期间，与非转基因植物相比，靶基因 StGAMyb-like1 在 stu-miR159a ST 植物中的激活增加。相比之下，干旱胁迫诱导 stu-miR159a OE 植物中靶基因的激活较弱。在 stu-miR159a ST 植物中，通过降低 stu-miR159a 活性同时增加 StGAMyb-like1 的表达，增加了花青素生物合成途径中关键基因 （StF3′5′H、StF3′H 和 StCHS2） 的表达。同时，在干旱处理下，stu-miR159a ST 植株的花青素积累高于非转基因植株，表明抗氧化能力增强，耐旱性提高。以上数据支持 stu-miR159a 是干旱胁迫的负调节因子，并为 stu-miR159a 介导的花青素生物合成途径在控制马铃薯耐旱性中的调节提供了新的见解。