Responses of mineral nutrient contents and transport in red clover under aluminum stress

Abstract

AbstractAluminum toxicity is considered the main factor underlying nutrient deficiencies and growth limitations of plants in acidic soil. Red clover (Trifolium pratense L.) is an important legume grass distributed worldwide, and it has medicinal value and strong adaptability to acidic soil with Al. However, few studies have focused on the relationship between nutrient uptake and Al stress. In this study, the changes in nutrients in the organs (root, stem, and leaf) of the cultivars Brilliant, Dory, and Haifa under high aluminum stress were detected. The results indicated that the contents of macronutrients and micronutrients were significantly influenced by Al3+ concentrations and the interaction between Al3+ concentrations and cultivars (P < 0.05). Under the Al3+ treatments, the contents of phosphorus (P) and magnesium (Mg) significantly decreased by 30.5% to 87.2% and 6.3% to 39.2%, respectively. However, potassium (K), zinc (Zn), and manganese (Mn) increased significantly, and these changes were closely correlated with Al resistance. The effect of Al stress on the copper (Cu) content varied with the plant organs, with Cu reduced in the roots but increased in the stems and leaves. Furthermore, the change ranges of nutrition contents in the sensitive cultivar were largest except for Cu. For example, the contents of Ca dropped by 26% in Brilliant leaves but decreased by less than 4% in the leaves of Haifa and Dory at 5‐mM Al3+. Moreover, the nutrient transport efficiencies were positively correlated with the Al3+ treatment concentrations in resistant cultivar except for Mg.