In plants, sugars are the key source of energy and metabolic building blocks. The systemic transport of sugars is essential for plant growth and morphogenesis. Plants evolved intricate molecular networks to effectively distribute sugars. The dynamic distribution of these osmotically active compounds is a handy tool for regulating cell turgor pressure, an instructive force in developmental biology. In this study, we have investigated the molecular mechanism behind the dual role of the receptor-like kinase CANAR. We functionally characterized a long non-coding RNA, CARMA, as a negative regulator of CANAR. Sugar-responsive CARMA specifically fine-tunes CANAR expression in the phloem, the route of sugar transport. Our genetic, molecular, microscopy, and biophysical data suggest that the CARMA–CANAR module controls the shoot-to-root phloem transport of sugars, allows cells to flexibly adapt to the external osmolality by appropriate water uptake, and thus adjust the size of vascular cell types during organ growth and development. Our study identifies a nexus of plant vascular tissue formation with cell internal pressure monitoring, revealing a novel functional aspect of long non-coding RNAs in developmental biology.

中文翻译：

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长链非编码 RNA 对植物细胞大小的蔗糖响应性渗透调节


在植物中，糖是能量和代谢组成部分的关键来源。糖的内系统运输对于植物生长和形态发生至关重要。植物进化出复杂的分子网络来有效地分配糖分。这些渗透活性化合物的动态分布是调节细胞膨胀压力的便捷工具，这是发育生物学中的一种指导力量。在这项研究中，我们研究了受体样激酶 CANAR 双重作用背后的分子机制。我们在功能上将长链非编码 RNA CARMA 表征为 CANAR 的负调节因子。糖反应性 CARMA 专门微调韧皮部（糖运输途径）中的 CANAR 表达。我们的遗传学、分子学、显微镜和生物物理学数据表明，CARMA-CANAR 模块控制糖的芽到根韧部的韧皮部运输，使细胞能够通过适当的水分吸收灵活地适应外部渗透压，从而在器官生长和发育过程中调整维管细胞类型的大小。我们的研究确定了植物维管组织形成与细胞内压监测的联系，揭示了发育生物学中长链非编码 RNA 的新功能方面。