Regulation of Female Germline Specification via Small RNA Mobility in Arabidopsis[OPEN]
Regulation of Female Germline Specification via Small RNA Mobility in Arabidopsis[OPEN]
复制标题
拟南芥中通过小 RNA 迁移性调节雌性种系规范
DOI：
10.1105/tpc.20.00126
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发表时间：
2020-09-01
期刊：
影响因子：
11.6
通讯作者：
Chen, Xuemei
中科院分区：
文献类型：
--
作者：
Su, Zhenxia;Wang, Nannan;Chen, Xuemei
在大多数有性生殖植物的胚珠中，一个下皮层细胞分化为大孢子母细胞（MMC），从而产生雌性生殖系，反式作用小干扰RNA（Trans-acting small interfering RNA，tasiR-ARF）被认为通过抑制拟南芥（Arabidopsis thaliana）中生长素反应因子3（AUXIN RESPONSE FACTOR 3，ARF 3）的表达来非细胞自主地发挥作用，以防止多个MMC的形成，但其潜在机制尚不清楚。在这里，我们研究了tasiR-ARF相关的细胞间调节机制。表达分析显示，tasiR-ARF生物发生途径的组分仅限于不同的胚珠细胞类型，从而限制了tasiR-ARF在珠心表皮的产生。我们还提供的数据表明，tasiR-ARF运动沿着中外侧轴进入皮下细胞和basipetally进入合点。此外，我们使用细胞类型特异性启动子在不同的胚珠细胞层中表达对tasiR-ARF调控具有抗性的ARF 3 m，ARF 3 m在MMC周围的下皮细胞中表达，而在表皮细胞中不表达，导致多MMC表型，表明tasiR-ARF抑制这些下皮细胞中的ARF 3以抑制异位MMC命运。对皮下表达ARF 3 m的植物进行的RNA测序分析表明，ARF 3可能通过植物激素途径调节MMC的特异性。我们的研究结果揭示了tasiR-ARF生物发生的复杂空间限制，这与tasiR-ARF的移动性一起使MMC分化中的细胞-细胞通讯成为可能。
In the ovules of most sexually reproducing plants, one hypodermal cell differentiates into a megaspore mother cell (MMC), which gives rise to the female germline.Trans-acting small interfering RNAs known as tasiR-ARFs have been suggested to act non-cell-autonomously to prevent the formation of multiple MMCs by repressingAUXIN RESPONSE FACTOR3(ARF3) expression in Arabidopsis (Arabidopsis thaliana), but the underlying mechanisms are unknown. Here, we examined tasiR-ARF-related intercellular regulatory mechanisms. Expression analysis revealed that components of the tasiR-ARF biogenesis pathway are restricted to distinct ovule cell types, thus limiting tasiR-ARF production to the nucellar epidermis. We also provide data suggesting tasiR-ARF movement along the mediolateral axis into the hypodermal cells and basipetally into the chalaza. Furthermore, we used cell type-specific promoters to expressARF3m, which is resistant to tasiR-ARF regulation, in different ovule cell layers.ARF3mexpression in hypodermal cells surrounding the MMC, but not in epidermal cells, led to a multiple-MMC phenotype, suggesting that tasiR-ARFs repressARF3in these hypodermal cells to suppress ectopic MMC fate. RNA sequencing analyses in plants with hypodermally expressedARF3mshowed thatARF3potentially regulates MMC specification through phytohormone pathways. Our findings uncover intricate spatial restriction of tasiR-ARF biogenesis, which together with tasiR-ARF mobility enables cell-cell communication in MMC differentiation.Intricate spatial restriction of tasiR-ARF biogenesis, together with tasiR-ARF mobility, enables cell-cell communication in MMC differentiation.