Direct evidence showing the effect of root surface iron plaque on arsenite and arsenate uptake into rice (Oryza sativa) roots
2005
Chen, Zheng | Zhu, Yong‐Guan | Liu, Wen‐Ju | Meharg, Andy A.
• The present study aimed to investigate the effects of root surface iron plaque on the uptake kinetics of arsenite and arsenate by excised roots of rice (Oryza sativa) seedlings. • The results demonstrated that the presence of iron plaque enhanced arsenite and decreased arsenate uptake. • Arsenite and arsenate uptake kinetics were adequately fitted by the Michaelis–Menten function in the absence of plaque, but produced poor fits to this function in the presence of plaque. • Phosphate in the uptake solution did not have a significant effect on arsenite uptake irrespective of the presence of iron plaque; however phosphate had a significant effect on arsenate uptake. Without iron plaque, phosphate inhibited arsenate uptake. The presence of iron plaque diminished the effect of phosphate on arsenate uptake, possibly through a combined effect of arsenate desorption from iron plaque.
显示更多 [+] 显示较少 [-]