National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, JNU Campus, New Delhi, 110067, India.
European Molecular Biology Laboratory, Meyerhofstrasse 1, Heidelberg, Germany.
Sci Rep. 2023 Dec 14;13(1):22258. doi: 10.1038/s41598-023-49093-2.
Arabidopsis microRNA165a (miR165a) targets Class III Homeodomain Leucine-Zipper (HD-ZIPIII) transcription factors to regulate various aspects of plant development and stress response. Over-expression of miR165a mimics the loss-of-function phenotype of HD-ZIPIII genes and leading to ectopic organ formation, shoot apical meristem (SAM) termination, loss of leaf polarity, and defective vasculature development. However, the molecular mechanisms underlying these phenotypes remain unresolved. Here, we over-expressed miR165a in a dexamethasone inducible manner and identified differentially expressed genes in the SAM through RNA-Seq. Simultaneously, using multi-channel FACS combined with RNA-Seq approach, we characterized global transcriptome patterns in miR165a expressing cell-types compared to HD-ZIPIII expressing cell-types and other cell-types in SAM. By integrating our results we identified sets of genes which are up-regulated by miR165a as well have enriched expression in miR165a cell-types, and vice-versa. Known plant development related genes such as HD-ZIPIII and their targets LITTLE ZIPPERs, Like AUXIN RESISTANT 2, BEL1-like homeodomain 6, ROTUNDIFOLIA like 16 were found to be down-regulated. Among the up-regulated genes, GIBBERELLIN 2-OXIDASEs, various elemental transporters (YSL3, ZIFL1, SULTR), and other transporter genes were prominent. Thus, the genes identified in this study help to unravel the molecular mechanism of miR165a and HD-ZIPIII regulated plant development and stress response.
拟南芥 microRNA165a (miR165a) 靶向 III 类同源域亮氨酸拉链 (HD-ZIPIII) 转录因子，以调节植物发育和应激反应的各个方面。miR165a 的过表达模拟了 HD-ZIPIII 基因的功能丧失表型，导致异位器官形成、茎尖分生组织 (SAM) 终止、叶片极性丧失和血管发育缺陷。然而，这些表型背后的分子机制仍未解决。在这里，我们以地塞米松诱导的方式过表达 miR165a，并通过 RNA-Seq 鉴定了 SAM 中的差异表达基因。同时，我们使用多通道 FACS 结合 RNA-Seq 方法，比较了 miR165a 表达细胞类型与 HD-ZIPIII 表达细胞类型和 SAM 中其他细胞类型的全局转录组模式。通过整合我们的结果，我们确定了一组由 miR165a 上调的基因以及在 miR165a 细胞类型中富集表达的基因，反之亦然。已知与植物发育相关的基因，如 HD-ZIPIII 及其靶基因 LITTLE ZIPPERs、Like AUXIN RESISTANT 2、BEL1-like homeodomain 6、ROTUNDIFOLIA like 16，被发现下调。在上调的基因中，赤霉素 2-氧化酶、各种元素转运体（YSL3、ZIFL1、SULTR）和其他转运体基因较为突出。因此，本研究中鉴定的基因有助于阐明 miR165a 和 HD-ZIPIII 调控植物发育和应激反应的分子机制。
