College of Life Sciences, Nanjing University, Nanjing, Jiangsu, China.
Cas Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, PR China.
Plant Signal Behav. 2022 Dec 31;17(1):2025322. doi: 10.1080/15592324.2021.2025322. Epub 2022 Jan 10.
Nutrient antagonism typically refers to the fact that too high a concentration of one nutrient inhibits the absorption of another nutrient. In plants, Ca (Calcium) and Mg (Magnesium) are the two most abundant divalent cations, which are known to have antagonistic interactions. Hence, maintaining their homeostasis is crucial for plant growth and development. In this study, we showed that MTP10 (Metal Tolerance Protein 10) is an important regulator for maintaining homeostasis of Mg and Ca in Arabidopsis. The mtp10 mutant displayed severe growth retardation in the presence of excess Mg, to which the addition of Ca was able to rescue the phenotype of mtp10 mutant. Additionally, the deficiency of Ca in the culture medium accelerated the high-Mg sensitivity of the mtp10 mutant. The yeast complementation assay suggested that AtMTP10 had no Ca transport activity. And the ICP-MS data further confirmed the antagonistic relationship between Ca and Mg, with the addition of Ca reducing the excessive accumulation of Mg and high-Mg inhibiting the uptake of Ca. We conclude that the Arabidopsis MTP10 is essential for the regulation of Mg and Ca homeostasis.
营养素拮抗作用通常是指一种营养素浓度过高会抑制另一种营养素的吸收。在植物中，Ca（钙）和 Mg（镁）是两种最丰富的二价阳离子，已知它们之间存在拮抗作用。因此，维持它们的体内平衡对植物的生长和发育至关重要。在这项研究中，我们表明 MTP10（金属耐受蛋白 10）是维持拟南芥中 Mg 和 Ca 体内平衡的重要调节剂。mtp10 突变体在过量 Mg 存在下表现出严重的生长迟缓，而添加 Ca 能够挽救 mtp10 突变体的表型。此外，培养基中 Ca 的缺乏加速了 mtp10 突变体对高 Mg 的敏感性。酵母互补测定表明 AtMTP10 没有 Ca 转运活性。ICP-MS 数据进一步证实了 Ca 和 Mg 之间的拮抗关系，添加 Ca 减少了过量的 Mg 积累，高 Mg 抑制了 Ca 的吸收。我们得出结论，拟南芥 MTP10 是调节 Mg 和 Ca 体内平衡所必需的。
