NMT历史上的今天

2015年10月14日，浙江理工大学熊杰、中国水稻所陶龙兴利用NMT在Environmental and Experimental Botany上发表了标题为Excessive nitrate enhances cadmium (Cd) uptake by up-regulating the expression of OsIRT1 in rice (Oryza sativa)的研究成果。

期刊：Environmental and Experimental Botany

主题：过量的**盐通过上调水稻（Oryza sativa）中OsIRT1的表达来提高镉（Cd）的吸收

标题：Excessive nitrate enhances cadmium (Cd) uptake by up-regulating the expression of OsIRT1 in rice (Oryza sativa)

影响因子：3.712

检测指标：Cd2+流速

检测部位：水稻根部

Cd2+流实验处理方法：

三周龄的水稻幼苗，在不同的NO3浓度（0mM、2.86mM、5.72mM）下培养7天，30 mM Cd2+处理30-60min

Cd2+流实验测试液成份：

30 μM CdCl2, 0.1 mM KCl, 0.05 mM MgCl2, 0.5 mM NaCl, 0.1 mM Na2SO4, 0.3 mM MES, pH 5.5

作者：浙江理工大学熊杰、中国水稻所陶龙兴

英文摘要

In order to pursue higher yield of rice, higher amount of NO3− is often used in rice production, but limited information is available on cadmium (Cd) uptake promoted by nitrate (NO3−) in rice.

Here, hydroponic experiments with integration of three NO3− levels (0 mM, 2.86 mM and 5.72 mM simplify as 0, NO3− and 2NO3−) and two Cd concentrations (0 and 100 μM) were conducted. Phenotypes and physiological indexes related to Cd uptake were measured; content changes of nitrogen, Cd and Fe also were measured. In addition, net Cd2+ flux was monitored and quantitative RT-PCR was applied to determine the expression of Fe/Cd transporters.

The results showed that although excessive NO3− had no significant promoting effect on rice growth in absence or presence of Cd, it enhanced Cd influx in elongation zone of rice roots and increased Cd accumulation in rice plants and grains. Excessive NO3− also increased OsIRT1 expression and Fe accumulation in rice seedlings in the absence or presence of Cd.

In conclusion, excessive NO3− increases OsIRT1 expression and Cd influx in elongation zone of rice roots, and then it increased Cd and Fe uptake and accumulation in rice plants and grains, which raises an increased-risk for human health.

中文摘要（谷歌机翻）
为了追求更高的水稻产量，通常在水稻生产中使用大量的NO3-，但是关于水稻中**盐（NO3-）促进镉（Cd）吸收的信息有限。

在这里，进行了整合三个NO3-浓度（0 mM，2.86 mM和5.72 mM简化为0，NO3-和2NO3-）和两个Cd浓度（0和100μM）的水培实验。测量与镉吸收有关的表型和生理指标；还测量了氮，镉和铁的含量变化。此外，监测净Cd2 +通量并应用定量RT-PCR确定Fe / Cd转运蛋白的表达。

结果表明，尽管过量的NO3-在没有或没有Cd的情况下对水稻的生长没有明显的促进作用，但是它增加了Cd在水稻根部伸长区的流入量，并增加了Cd在水稻和谷物中的积累。在没有或没有镉的情况下，过量的NO3-也会增加水稻幼苗中OsIRT1的表达和铁的积累。

总之，过量的NO3-会增加稻根伸长区OsIRT1的表达和Cd的流入，然后增加稻米和谷物中Cd和Fe的吸收和积累，从而增加人体健康的风险。

Effects of different concentrations of nitrate (NO3􀀂) on root net Cd2+ influx in rice seedlings. Root net Cd2+ influx of 3-week-old rice seedlings cultivated in 0, 2.86 and 5.72 mM NO3􀀂 conditions for 7 days. Then, 30 mM Cd2+ were added into the solution for 30–60 min. Net Cd flux of meristematic zone (B and D) and elongation zone (A and C) of the main root were monitored and steady-state Cd flux was recorded for 10 min. Bar indicates 50 mm in (A and B), the values are means 􀀁 SE (n = 107), different letters on the bar indicate significant differences at P = 0.05.

文章链接：

https://www.sciencedirect.com/science/article/abs/pii/S0098847215300228?via%3Dihub