Effects of silicon on arsenate uptake by rice (Oryza sativa L.) seedlings in solution culture

摘要

Solution culture experiments were conducted to investigate the effect of silicon (Si) on arsenic (As (V)) uptake by rice. Both intemal and external Si significantly decreased shoot and root As concentrations. Meanwhile, we investigated the possible mechanism of Si effects on As (V) uptake by using a wild-type rice and its low-silicon (lsil) mutant. The results showed that Si significantly decreased shoot and root As concentrations of wild type rice, but had little effect on those of the mutant rice. Arsenic speclarion analysis of the xylem sap of the wild type rice indicated that Si significantly decreased As (III) concentration but had little effect on As (V) concentration in xylem sap. These results further showed that As (III) may be loaded to xylem partly via the active Si transporter. It may be the mechanism involved in Si mediated reduction of As uptake by rice.