Polarized transport across root epithelia

First author: Priya Ramakrishna; Affiliations: University of Geneva (日内瓦大学): Geneva, Switzerland

Corresponding author: Marie Barberon

Plant roots explore the soil to acquire water and nutrients which are often available at concentrations that drastically differ from the plant’s actual need for growth and development. This stark difference between availability and requirement can be dealt with owing to the root’s architecture as an inverted gut. In roots, the two epithelial characteristics (selective acquisition and diffusion barrier) are split between two cell layers: the epidermis at the root periphery and the endodermis as the innermost cortical cell layer around the vasculature. Polarized transport of nutrients across the root epithelium can be achieved through different pathways: apoplastic, symplastic, or coupled transcellular. This review highlights different features of the root that allow this polarized transport. Special emphasis is placed on the coupled transcellular pathway, facilitated by polarized nutrient carriers along root cell layers but barred by suberin lamellae in endodermal cells.

植物的根生长于土壤之中，主要作用是获取水分和营养，但通常情况下这些物质的浓度都不是正好满足于植物的生长发育，或多或少，没个定数。植物因为其根系结构可以解决这种资源可利用性与本身实际需求之间的不相符问题。在植物的根中，可以根据上皮组织的两个功能：选择性获取和扩散屏障分为两个细胞层，一个是根周表皮，还有一个是紧密围绕在维管周边的最内层皮质细胞，也就是内皮层。跨越不同根表皮组织的极性运输可以通过多种方式实现，包括质外体运输、共质体运输和偶联跨细胞运输。本综述突出了根中不同极性运输方式的特性。作者尤其关注了偶联跨细胞运输，其能够被根中沿着细胞层方向的极性营养载体所促进，但是内皮层细胞中的栓质层能够阻挡该运输。

通讯：Marie Barberon (https://biveg.unige.ch/labs/barberon/)

研究方向：植物根中的营养运输以及植物对非生物胁迫的适应。

doi: https://doi.org/10.1016/j.pbi.2019.05.010

Journal: Current Opinion in Plant Biology

Published date: 2019