Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, Key Laboratory of Plant-Soil Interactions of the Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, PR China.
Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, Key Laboratory of Plant-Soil Interactions of the Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, PR China.
Environ Pollut. 2022 Nov 1;312:120039. doi: 10.1016/j.envpol.2022.120039. Epub 2022 Aug 27.
The different effects of selenite and selenate on the fate of As and the function of iron plaque in the interaction between Se and As are poorly understood. Rice seedlings (Oryza sativa L.) were selected as experimental plants in this study, the hydroponic experiments were conducted to investigate the possible regulatory roles of selenite and selenate on the uptake, translocation, and transformation of arsenite or arsenate accompanied by iron plaque. In arsenite- and arsenate-treated rice, the Fe30 treatments stimulated root uptake by 12.4-39.8% and 18.6-37.0%, respectively, but inhibited the movement of As from iron plaque to the roots, resulting in the absorption of a considerable amount of As on iron plaque. Regardless of the iron plaque formation, selenite (selenate) significantly increased (decreased) the root uptake of arsenite and arsenate by 28.1-53.0% and 40.0%-61.7%, respectively (45.6-56.3% and 42.5-47.7%, respectively). Interestingly, the supply of selenite significantly reduced root-to-shoot As translocation by 71.9-77.3% and 66.2-67.7%, respectively, in arsenite- and arsenate-treated rice seedlings; however, a significant increase (90.5-122.9%) was induced by selenate was found only in the arsenate-treated plants. Furthermore, the translocation of As from iron plaque to the roots was significantly increased (decreased) by selenite (selenate). As and Fe in iron plaque were significantly positively correlated in all As-treated rice plants, and this correlation was more profound than that in the shoots and roots. However, neither Fe treatments nor inorganic Se addition affected the interconversion between As(III) and As(V) obviously; and As(III) was the dominant species in both shoots (68.3-84.9%) and roots (90.7-98.2%). Our results indicate selenite and selenate are effective in reducing the As accumulation in an opposite way, and the presence of iron plaque had no obvious impact on the interaction between Se and As in rice plants.
亚硒酸盐和硒酸盐对砷命运的不同影响以及铁帽在硒与砷相互作用中的功能尚不清楚。本研究选用水稻幼苗（Oryza sativa L.）作为实验植物，通过水培实验研究了亚硒酸盐和硒酸盐对砷酸盐或亚砷酸盐伴随铁帽的吸收、转运和转化的可能调控作用。在砷酸盐和砷酸盐处理的水稻中，Fe30 处理分别刺激根系吸收 12.4-39.8%和 18.6-37.0%，但抑制砷从铁帽向根部的移动，导致大量砷被吸收到铁帽上。无论铁帽形成与否，亚硒酸盐（硒酸盐）均显著增加（降低）根系对亚砷酸盐和砷酸盐的吸收，分别增加 28.1-53.0%和 40.0%-61.7%（分别增加 45.6-56.3%和 42.5-47.7%）。有趣的是，亚硒酸盐的供应显著降低了砷酸盐和砷酸盐处理的水稻幼苗根到茎的砷转运，分别降低 71.9-77.3%和 66.2-67.7%；然而，仅在砷酸盐处理的植物中发现硒酸盐诱导的转运显著增加（90.5-122.9%）。此外，亚硒酸盐（硒酸盐）显著增加（降低）了砷从铁帽向根部的转运。所有砷处理的水稻植株中，铁帽中的砷和铁均呈显著正相关，且这种相关性比茎和根中的相关性更显著。然而，Fe 处理或无机硒添加均未明显影响砷（III）和砷（V）之间的相互转化；且砷（III）是地上部（68.3-84.9%）和根部（90.7-98.2%）的主要形态。研究结果表明，亚硒酸盐和硒酸盐通过相反的方式有效降低了砷的积累，铁帽的存在对水稻植株中硒与砷的相互作用没有明显影响。
