Biology Division, Indian Institute of Science Education and Research, Pune 411008, Maharashtra, India.
Biology Division, Indian Institute of Science Education and Research, Pune 411008, Maharashtra, India
Plant Physiol. 2020 Jan;182(1):185-203. doi: 10.1104/pp.19.00416. Epub 2019 Aug 19.
Polycomb Repressive Complexes (PRC1 and PRC2) regulate developmental transitions in plants. AtBMI1, a PRC1 member, represses micro RNA156 (miR156) to trigger the onset of adult phase in Arabidopsis (). miR156 overexpression (OE) reduces below-ground tuber yield, but stimulates aerial tubers in potato ( ssp ) under short-day (SD) photoperiodic conditions. Whether PRC members could govern tuber development through photoperiod-mediated regulation of miR156 is unknown. Here, we investigated the role of two PRC proteins, StMSI1 (PRC2 member) and StBMI1-1, in potato development. In wild-type plants, and miR156 levels increased in stolon, whereas - decreased under SD conditions. - and --antisense (AS) lines produced pleiotropic effects, including altered leaf architecture/compounding and reduced below-ground tuber yield. Notably, these lines showed enhanced miR156 accumulation accompanied by aerial stolons and tubers from axillary nodes, similar to miR156-OE lines. Further, grafting of - or -- on wild-type stock resulted in reduced root biomass and showed increased accumulation of miR156a/b and -c precursors in the roots of wild-type stocks. RNA-sequencing of axillary nodes from -OE and -- lines revealed downregulation of auxin and brassinosteroid genes, and upregulation of cytokinin transport/signaling genes, from 1,023 differentially expressed genes shared between the two lines. Moreover, we observed downregulation of genes encoding H2A-ubiquitin ligase and StBMI1-1/3, and upregulation of Trithorax group H3K4-methyl-transferases in - Chromatin immunoprecipitation-quantitative PCR confirmed H3K27me3-mediated suppression of -/, and H3K4me3-mediated activation of miR156 in - plants. In summary, we show that cross talk between histone modifiers regulates miR156 and alters hormonal response during aerial tuber formation in potato under SD conditions.
多梳抑制复合物（PRC1 和 PRC2）调节植物发育的转变。在拟南芥中，PRC1 成员 BMI1 抑制 micro RNA156（miR156）以触发成年期的开始（）。miR156 的过表达（OE）降低了地下块茎的产量，但在短日照（SD）光周期条件下刺激了马铃薯（ssp）的地上块茎。PRC 成员是否可以通过 miR156 的光周期介导调节来控制块茎发育尚不清楚。在这里，我们研究了两个 PRC 蛋白 StMSI1（PRC2 成员）和 StBMI1-1 在马铃薯发育中的作用。在野生型 植株中，在地上茎中 和 miR156 水平增加，而在 SD 条件下则减少。-和--反义（AS）系产生了多种表型效应，包括改变叶结构/复杂化和地下块茎产量降低。值得注意的是，这些系表现出增强的 miR156 积累，伴随着腋生节点的地上茎和块茎，类似于 miR156-OE 系。此外，-或--在野生型植株上的嫁接导致根系生物量减少，并显示出野生型植株根系中 miR156a/b 和-c 前体的积累增加。-OE 和--系腋生节点的 RNA 测序揭示了生长素和油菜素内酯基因的下调，以及细胞分裂素转运/信号基因的上调，这两种基因在两个系之间共享的 1023 个差异表达基因中。此外，我们观察到编码 H2A-泛素连接酶和 StBMI1-1/3 的基因下调，以及 Trithorax 组 H3K4-甲基转移酶的上调在 -染色质免疫沉淀定量 PCR 证实了 H3K27me3 介导的对-/-的抑制，以及 H3K4me3 介导的 miR156 在 -植物中的激活。总之，我们表明组蛋白修饰物之间的串扰调节 miR156，并在 SD 条件下改变马铃薯地上块茎形成过程中的激素反应。
