Manganese Absorption and Transport in Rice

The absorptive patterns of Mn2+ in excised rice roots, leaf tissues and intact plants, were studied. The rates of absorption of Mn2+ followed different patterns in the roots and the leaf tissues. The uptake from 0.1 and 5 mM MnSO4 was found to be sensitive to metabolic inhibitors. The time course of uptake from 0.1 mM and 5 mM MnSO4 followed a biphasic pattern which represented only the metabolic component of absorption. A secondary biphasic pattern of uptake at 5 mM MnSO4 (one at 20 min and another at 80 min) appears quite anomalous and is probably related to structural virations or cellular compartments. When absorption and transport of Mn2+ were measured in intact rice and wheat plants, it was found that Mn2+ was easily translocated to shoot from roots and the transport of Mn2+ was comparable to that of K+.