CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Lucknow, India; CSIR-National Botanical Research Institute, Council of Scientific and Industrial Research (CSIR-NBRI), Rana Pratap Marg, Lucknow, 226001, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Lucknow, India.
Biochem Biophys Res Commun. 2024 Apr 30;706:149764. doi: 10.1016/j.bbrc.2024.149764. Epub 2024 Mar 8.
Recent studies propose that primary transcripts of miRNAs (pri-miRNAs) contain small Open Reading Frames (ORFs) capable of encoding miRNA-encoded peptides (miPEPs). These miPEPs can function as transcriptional regulators for their corresponding pri-miRNAs, ultimately enhancing mature miRNA accumulation. Notably, pri-miR408 encodes the functional peptide miPEP408, regulating expression of miR408 and its target genes, providing plant tolerance to stresses. While miPEPs are crucial regulators, the factors governing them are have not been studied in detail. Here, we explored the light-dependent regulation of miPEP408 in Arabidopsis. Expression analysis during dark-light transitions revealed light-induced transcription and accumulation of the miPEP408. As the promoter of miR408 contains cis-acting elements responsible for binding to the bZIP-type transcription factor ELONGATED HYPOCOTYL5 (HY5), known for light-mediated regulation in plants, we studied its involvement in the regulation of miR408. Analysis of HY5 mutant (hy5-215), complemented line (HY5OX/hy5), and CONSTITUTIVE PHOTOMORPHOGENIC 1 mutant (cop1-4) plants supported HY5's positive regulation of miPEP408. Grafting and GUS assays further suggested the role of HY5 as a shoot-root mobile signal inducing light-dependent miPEP408 expression. This study underscores the regulatory impact of light on small peptides, exemplified by miPEP408, mediated by the key transcription factor HY5.
最近的研究表明，miRNA 的初级转录本（pri-miRNAs）包含能够编码 miRNA 编码肽（miPEPs）的小开放阅读框（ORFs）。这些 miPEPs 可以作为其相应的 pri-miRNAs 的转录调节剂，最终增强成熟 miRNA 的积累。值得注意的是，pri-miR408 编码功能性肽 miPEP408，调节 miR408 及其靶基因的表达，为植物提供对胁迫的耐受性。虽然 miPEPs 是重要的调节剂，但调节它们的因素尚未得到详细研究。在这里，我们探讨了 Arabidopsis 中 miPEP408 的光依赖性调节。在黑暗-光照转变过程中的表达分析显示，miPEP408 受到光照诱导的转录和积累。由于 miR408 的启动子包含顺式作用元件，负责与 bZIP 型转录因子 ELONGATED HYPOCOTYL5（HY5）结合，HY5 已知在植物中参与光介导的调节，我们研究了它在 miR408 调节中的作用。对 HY5 突变体（hy5-215）、互补系（HY5OX/hy5）和 CONSTITUTIVE PHOTOMORPHOGENIC 1 突变体（cop1-4）的分析支持 HY5 对 miPEP408 的正调节。嫁接和 GUS 分析进一步表明，HY5 作为一种在 shoot-root 间移动的信号分子，诱导光依赖性 miPEP408 表达。这项研究强调了光对小分子（如 miPEP408）的调节作用，由关键转录因子 HY5 介导。
