Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, 13416-000, Brazil.
Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 111, 1000, Ljubljana, Slovenia.
Sci Rep. 2021 Jul 2;11(1):13746. doi: 10.1038/s41598-021-93396-1.
Phosphorus (P) and zinc (Zn) uptake and its physiological use in plants are interconnected and are tightly controlled. However, there is still conflicting information about the interactions of these two nutrients, thus a better understanding of nutritional homeostasis is needed. The objective of this work was to evaluate responses of photosynthesis parameters, P-Zn nutritional homeostasis and antioxidant metabolism to variation in the P × Zn supply of cotton (Gossypium hirsutum L.). Plants were grown in pots and watered with nutrient solution containing combinations of P and Zn supply. An excess of either P or Zn limited plant growth, reduced photosynthesis-related parameters, and antioxidant scavenging enzymes. Phosphorus uptake favoured photochemical dissipation of energy decreasing oxidative stress, notably on Zn-well-nourished plants. On the other hand, excessive P uptake reduces Zn-shoot concentration and decreasing carbonic anhydrase activity. Adequate Zn supply facilitated adaptation responses to P deficiency, upregulating acid phosphatase activity, whereas Zn and P excess were alleviated by increasing P and Zn supply, respectively. Collectively, the results showed that inter ionic effects of P and Zn uptake affected light use and CO assimilation rate on photosynthesis, activation of antioxidant metabolism, acid phosphatase and carbonic anhydrase activities, and plant growth-related responses to different extents.
磷（P）和锌（Zn）的吸收及其在植物中的生理利用是相互关联的，并受到严格控制。然而，关于这两种营养物质的相互作用仍然存在相互矛盾的信息，因此需要更好地了解营养动态平衡。本工作的目的是评估光合作用参数、P-Zn 营养动态平衡和抗氧化代谢对棉花（Gossypium hirsutum L.）对 P 和 Zn 供应变化的响应。植物在盆中生长，用含有 P 和 Zn 供应组合的营养液浇水。P 或 Zn 的过量供应限制了植物的生长，降低了与光合作用相关的参数，并降低了抗氧化剂清除酶的活性。P 的吸收有利于光化学能量耗散，从而降低氧化应激，特别是在 Zn 营养良好的植物上。另一方面，P 吸收过多会降低 Zn 在地上部分的浓度并降低碳酸酐酶的活性。适量的 Zn 供应促进了对 P 缺乏的适应反应，增加了酸性磷酸酶的活性，而 Zn 和 P 的过量则分别通过增加 P 和 Zn 的供应得到缓解。总的来说，结果表明，P 和 Zn 吸收的离子间效应不同程度地影响了光合作用的光利用和 CO 同化率、抗氧化代谢、酸性磷酸酶和碳酸酐酶活性以及与植物生长相关的响应。
