Sainsbury Laboratory, University of Cambridge, 47 Bateman Street, Cambridge CB2 1 LR, UK
Biol Open. 2020 Nov 12;9(11):bio055541. doi: 10.1242/bio.055541.
Auxin is an endogenous small molecule with an incredibly large impact on growth and development in plants. Movement of auxin between cells, due to its negative charge at most physiological pHs, strongly relies on families of active transporters. These proteins import auxin from the extracellular space or export it into the same. Mutations in these components have profound impacts on biological processes. Another transport route available to auxin, once the substance is inside the cell, are plasmodesmata connections. These small channels connect the cytoplasms of neighbouring plant cells and enable flow between them. Interestingly, the biological significance of this latter mode of transport is only recently starting to emerge with examples from roots, hypocotyls and leaves. The existence of two transport systems provides opportunities for reciprocal cross-regulation. Indeed, auxin levels influence proteins controlling plasmodesmata permeability, while cell-cell communication affects auxin biosynthesis and transport. In an evolutionary context, transporter driven cell-cell auxin movement and plasmodesmata seem to have evolved around the same time in the green lineage. This highlights a co-existence from early on and a likely functional specificity of the systems. Exploring more situations where auxin movement via plasmodesmata has relevance for plant growth and development, and clarifying the regulation of such transport, will be key aspects in coming years.This article has an associated Future Leader to Watch interview with the author of the paper.
生长素是一种内源性小分子，对植物的生长和发育有巨大影响。由于在大多数生理 pH 值下带负电荷，生长素在细胞间的移动强烈依赖于一系列活性转运蛋白。这些蛋白质将生长素从细胞外空间输入或输出到细胞外空间。这些成分的突变对生物过程有深远的影响。生长素进入细胞后的另一种运输途径是胞间连丝连接。这些小通道连接着相邻植物细胞的细胞质，使它们之间能够进行物质交换。有趣的是，这种运输方式的生物学意义最近才开始显现，例如在根、下胚轴和叶子中。两种运输系统的存在为相互交叉调节提供了机会。事实上，生长素水平影响控制胞间连丝通透性的蛋白质，而细胞间通讯则影响生长素的生物合成和运输。从进化的角度来看，由转运蛋白驱动的细胞间生长素运动和胞间连丝似乎在绿色谱系中同时进化。这突出了早期的共存和系统的功能特异性。探索生长素通过胞间连丝运输与植物生长和发育相关的更多情况，并阐明这种运输的调节，将是未来几年的关键方面。本文有一篇相关的未来领袖观察采访，采访对象是本文的作者。
