Salt Stress Affects the Redox Status of Arabidopsis Root Meristems.
Salt Stress Affects the Redox Status of Arabidopsis Root Meristems.
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DOI：
10.3389/fpls.2016.00081
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发表时间：
2016
影响因子：
5.6
通讯作者：
Feldman LJ
中科院分区：
文献类型：
--
作者：
Jiang K;Moe-Lange J;Hennet L;Feldman LJ
我们报告的氧化还原状态（配置文件）的特定群体的细胞，包括拟南芥根尖。对于最近发芽，3-5天的幼苗，我们表明，最还原氧化还原状态的根尖区域包括根冠起始，静止中心和近端分生组织的最远端部分，并与（覆盖）生长素最大的区域相一致。随着向基部移动，进一步进入近端分生组织，并且取决于生长条件，氧化还原状态变得更加氧化，在界定近端分生组织的两个边界之间的氧化还原电位差为5-10 mV。在根轴上近端分生组织的细胞停止分裂并进入过渡区的点处，氧化还原电位趋于稳定，并且在整个过渡区中或多或少保持不变。随着细胞离开过渡区并进入伸长区，氧化还原电位变得更加氧化。用盐（50，100和150 mM NaCl）处理根会导致根分生组织结构和发育发生显著变化，并且在此之前会发生氧化还原曲线的变化，氧化还原曲线会发生变化，最初变得更加氧化，根冠，根冠起始和静止中心的氧化还原电位发生明显变化。暴露于相对温和水平的盐（<100 mM）的根能够在暴露于盐后3-6天重新建立正常的盐前处理氧化还原曲线。与盐相关的氧化还原谱的变化相一致的是生长素转运蛋白（AUX 1，PIN 1/2）的分布变化，其在其定位中变得更加分散。我们得出结论，盐胁迫影响根分生组织的维持，部分，通过氧化还原和生长素运输的变化。
We report the redox status (profiles) for specific populations of cells that comprise the Arabidopsis root tip. For recently germinated, 3–5-day-old seedlings we show that the region of the root tip with the most reduced redox status includes the root cap initials, the quiescent center and the most distal portion of the proximal meristem, and coincides with (overlays) the region of the auxin maximum. As one moves basally, further into the proximal meristem, and depending on the growth conditions, the redox status becomes more oxidized, with a 5–10 mV difference in redox potential between the two borders delimiting the proximal meristem. At the point on the root axis at which cells of the proximal meristem cease division and enter the transition zone, the redox potential levels off, and remains more or less unchanged throughout the transition zone. As cells leave the transition zone and enter the zone of elongation the redox potentials become more oxidized. Treating roots with salt (50, 100, and 150 mM NaCl) results in marked changes in root meristem structure and development, and is preceded by changes in the redox profile, which flattens, and initially becomes more oxidized, with pronounced changes in the redox potentials of the root cap, the root cap initials and the quiescent center. Roots exposed to relatively mild levels of salt (<100 mM) are able to re-establish a normal, pre-salt treatment redox profile 3–6 days after exposure to salt. Coincident with the salt-associated changes in redox profiles are changes in the distribution of auxin transporters (AUX1, PIN1/2), which become more diffuse in their localization. We conclude that salt stress affects root meristem maintenance, in part, through changes in redox and auxin transport.