Improving zinc supply enhances cotton nutritional phosphorus efficiency

Abstract

Phosphorus (P) and zinc (Zn) uptake and their physiological use in plants are interconnected and tightly controlled. However, the extent to which these nutrients contribute to plants nutritional homeostasis remains poorly understood, as well as there is conflicting information about the interaction of these two nutrients, requiring a better understanding of nutritional homeostasis in different cultivars of cotton plants. Thus, this study aimed to evaluate the effect of Zn supply on the efficiency of P uptake and use in different cotton (Gossypium hirsutum L.) cultivars (IMA 8001 WS; TMG 44B2RF; FM 966). Plants were grown in Hoagland nutrient solution containing different levels of P and Zn (low and adequate supply). Biomass and mineral nutrition were evaluated in plants receiving contrasting levels of P and Zn supply. A balanced P and Zn supply (4 mM P × 4 µM Zn) enabled the highest biomass accumulation, while an imbalanced supply of these nutrients reduced P and Zn accumulation in the shoots in all cultivars. The TMG and FM cultivars grown under low P (0.5 mM) supply showed higher dry mass production and efficiency of P use when cultivated with adequate Zn (4.0 µM) than with low Zn (0.5 µM). The IMA cultivar demonstrated no effect of Zn on efficiency of P use. However, Zn supply in cotton increased P uptake in all cultivars grown with an adequate P supply. These results suggest that agricultural management strategies should aim for balanced mineral nutrition by considering cultivars to optimize yields and resource-use efficiencies.