Effects of low-molecular-weight organic acids on uptake of lanthanum by wheat roots

Effects of low-molecular-weight organic acids (LMWOAs) on the uptake of lanthanum by wheat (Triticum aestivum L.) roots were studied under hydroponic conditions. Acetic and malic acids were chosen as the representatives of LMWOAs. Uptake kinetics of lanthanum indicated that when lanthanum concentrations in the uptake solutions were high or uptake time was long lanthanum uptake by roots was enhanced by LMWAOs. After wheat was cultured in the uptake solution of lanthanum containing acetic or malic acids for 48 h the uptake of lanthanum by roots increased by 57 and 44%, respectively, compared with that in the absence of acetic and malic acids. The increase in uptake of lanthanum was determined by the ratio of the concentrations of organic acids to lanthanum in the uptake solutions. The highest uptake of lanthanum was obtained at the ratio of 5:1.