Physiological and biochemical changes in young maize plants under iron deficiency. 3. Concentration and distribution of some nutrient elements

Abstract

Young maize plants (hybrid Knezha‐650), grown hydroponically, were supplied with different amounts (7.5–0 mg Fe L^‐1) of iron (Fe). At 14, 21, and 28 days, concentrations of Fe, phosphorus (P), calcium (Ca), magnesium (Mg), zinc (Zn), manganese (Mn), and copper (Cu) in leaves were determined. Iron deficiency resulted in rapid and strong decrease of root Fe concentration. Despite the low total Fe in the leaves of chlorotic plants, the Fe concentration in leaves did not reflect the Fe supply to plants. In Fe‐deficient plants, the tissue concentrations of nutrient elements other than Fe changed too, the alterations in the studied microelements being greater. Changes in Mn and Zn concentrations in leaves depended highly on the degree of Fe deficiency. Copper transport to leaves seemed to be hampered and the main part of it was retained by roots. As compared to control plants, the portion of Fe, Mn, and Ca in roots was smaller in chlorotic plants. The opposite trend was found for Cu and Mg. Increased Zn/Fe, Mn/Fe, and possibly P/Fe ratios might be related to Fe inactivation in leaves under Fe deficiency. Plants supplied with 1/10 of optimum Fe required “adapted”; partially to Fe deficiency which was expressed by a smaller departure from the norm for micronutrient concentrations in leaves at the end of the experiment as compared to the earlier stages of growth.