Effects of P on the Uptake and Transport of Cd and As in Wheat Seedlings

Abstract

The aim of this study was to explore the effect of P on the physiological mechanism of Cd and As uptake and transport of wheat seedlings. Taking Bainong 207 as the test material, we investigated the effects of exogenous P supply and P deficiency treatment on the growth, root morphology, photosynthetic parameters, antioxidant system, ion content, and rhizome transfer coefficient of wheat seedlings under Cd and As stress using hydroponic experiments. The results showed that compared with that in the P deficiency treatment, the supply of exogenous P significantly increased the chlorophyll content of wheat seedlings under As stress, promoted the growth and development of roots, and increased biomass, whereas there were no significant effects on the growth of wheat seedlings under Cd stress. The contents of P and Cd in the root system under the condition of Cd stress were significantly increased by the supply of exogenous P, and the contents of P and Cd in the aboveground part were reduced. At the same time, the P and As content in the shoot and the transfer coefficient of As from the root to the shoot under As stress were significantly improved. Therefore, the effects of P on the poisoning of wheat Cd and As in this study showed obvious differences. Under As stress, exogenous P supply mainly promoted the growth of wheat seedlings by improving the transport of As from the root to the shoot and the CAT activity in the root system, reducing the poisoning of As in wheat. Under Cd stress, P and Cd showed a certain synergistic effect, and the toxic effect of Cd on wheat was aggravated to a certain extent after the supply of P.