Ejiri Masato, Fukao Takeshi, Miyashita Tomoki, Shiono Katsuhiro
Graduate School of Bioscience and Biotechnology, Fukui Prefectural University, 4-1-1 Matsuoka-Kenjojima, Eiheiji, Fukui 910-1195, Japan.
Breed Sci. 2021 Feb;71(1):40-50. doi: 10.1270/jsbbs.20110. Epub 2021 Jan 30.
Internal aeration is crucial for root growth under waterlogged conditions. Many wetland plants have a structural barrier that impedes oxygen leakage from the basal part of roots called a radial oxygen loss (ROL) barrier. ROL barriers reduce the loss of oxygen transported via the aerenchyma to the root tips, enabling long-distance oxygen transport for cell respiration at the root tip. Because the root tip does not have an ROL barrier, some of the transferred oxygen is released into the waterlogged soil, where it oxidizes and detoxifies toxic substances (e.g., sulfate and Fe) around the root tip. ROL barriers are located at the outer part of roots (OPRs). Their main component is thought to be suberin. Suberin deposits may block the entry of potentially toxic compounds in highly reduced soils. The amount of ROL from the roots depends on the strength of the ROL barrier, the length of the roots, and environmental conditions, which causes spatiotemporal changes in the root system's oxidization pattern. We summarize recent achievements in understanding how ROL barrier formation is regulated and discuss opportunities for breeding waterlogging-tolerant crops.
在渍水条件下，内部通气对根系生长至关重要。许多湿地植物具有一种结构屏障，可阻止氧气从根的基部泄漏，这种屏障称为径向氧损失（ROL）屏障。ROL屏障减少了通过通气组织输送到根尖的氧气损失，使氧气能够进行长距离运输，以供根尖细胞呼吸。由于根尖没有ROL屏障，一些转移来的氧气会释放到渍水土壤中，在那里它会氧化并解毒根尖周围的有毒物质（如硫酸盐和铁）。ROL屏障位于根的外部（OPR）。其主要成分被认为是木栓质。木栓质沉积可能会阻止潜在有毒化合物进入高度还原的土壤。根系的ROL量取决于ROL屏障的强度、根的长度和环境条件，这会导致根系氧化模式的时空变化。我们总结了在理解ROL屏障形成如何被调控方面的最新成果，并讨论了培育耐渍作物的机会。
