NMT历史上的今天丨根系不均一盐胁迫提升植物水分利用率的机制

2011年11月25日，山东省农科院董合忠、孔祥强利用NMT在Journal of Experimental Botany 上发表了标题为Effects of non-uniform root zone salinity on water use Na+ recirculation, and Na+ and H+ flux in cotton的研究成果。

期刊：Journal of Experimental Botany

主题：根系不均一盐胁迫提升植物水分利用率的机制

标题：Effects of non-uniform root zone salinity on water use Na+ recirculation, and Na+ and H+ flux in cotton

影响因子：4.818

检测指标：Na+、H+流速

作者：山东省农科院董合忠、孔祥强

英文摘要

A new split-root system was established through  grafting to study cotton response to non-uniform salinity. Each root  half was treated with either uniform (100/100 mM) or non-uniform NaCl  concentrations (0/200 and 50/150 mM).

In contrast to uniform  control, non-uniform salinity treatment improved plant growth and water  use, with more water absorbed from the non- and low salinity side.  Non-uniform treatments decreased Na+ concentrations in leaves. The [Na+]  in the ‘0’ side roots of the 0/200 treatment was significantly higher  than that in either side of the 0/0 control, but greatly decreased when  the ‘0’ side phloem was girdled, suggesting that the increased [Na+] in  the ‘0’ side roots was possibly due to transportation of foliar Na+ to  roots through phloem.

Plants under non-uniform salinity extruded  more Na+ from the root than those under uniform salinity. Root Na+  efflux in the low salinity side was greatly enhanced by the higher  salinity side. NaCl-induced Na+ efflux and H+ influx were inhibited by  amiloride and sodium orthovanadate, suggesting that root Na+ extrusion  was probably due to active Na+/H+ antiport across the plasma membrane.

Improved  plant growth under non-uniform salinity was thus attributed to  increased water use, reduced leaf Na+ concentration, transport of  excessive foliar Na+ to the low salinity side, and enhanced Na+ efflux  from the low salinity root.

中文摘要（谷歌机翻）

通过嫁接建立了一个新的分根系统，以研究棉花对盐度不均匀的响应。每个根部均用均一的（100/100 nonmM）或不均一的氯化钠浓度（0/200和50/150 mM）处理。

与统一控制相反，非均匀盐度处理改善了植物生长和水分利用，从非盐度和低盐度侧吸收了更多的水。不均匀处理降低了叶片中的Na+浓度。0/200处理的'0'侧根中的[Na+]显着高于0/0对照中任一侧的[Na+]，但当'0'侧韧皮部被束腰时，其[Na+]大大降低，表明[  [0]侧根中的Na+]可能是由于叶面Na+通过韧皮部转运至根。

盐度不均匀的植物比盐度均匀的植物从根部挤出的Na+更多。低盐度一侧的根Na+流出量被高盐度一侧大大增强。NaCl诱导的Na+流出和H+流入被阿米洛利和原钒酸钠抑制，这表明根Na+的挤出可能是由于跨质膜的活性Na+ / H+逆向转运所致。

因此，在非均匀盐度下植物生长的改善归因于增加的水分利用，降低的叶片Na+浓度，过量的叶面Na+向低盐度侧的运输以及从低盐度根部提高的Na+外排。

Effects of non-uniform (0/200 mM and 50/150 mM NaCl)  and uniform (0/0, 50/50, 100/100, and 150/150 mM NaCl) root zone  salinity on net Na+ fluxes in roots of cotton at 1 d (A) and 7 d (B)  after treatment. The data are main fluxes of Na+ within the measuring  periods (15 min). Values are means 6SE (n¼6). Bars with different  letters (a, b, and c) differ significantly at P < 0.05.