文献类型： 外文期刊

作者： Zhang Feng ¹ ; Peng Rui ³ ; Wang Lifeng ¹ ; Jiang Huidan ¹ ;

作者机构： 1.Hunan Acad Agr Sci, Biotechnol Res Inst, Changsha 410125, Peoples R China

2.Hunan Univ, Grad Sch, Longping Branch, Changsha 410125, Peoples R China

3.Hunan Hybrid Rice Res Ctr, Changsha 410125, Peoples R China

关键词： Rice growth seasons; Cd; Soil Eh; Fe reduction; S reduction; Bacteria

期刊名称：ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY （ 影响因子：7.129； 五年影响因子：7.284 ）

ISSN： 0147-6513

年卷期： 2022 年 236 卷

页码：

收录情况： SCI

摘要： Effects of iron and sulfur redox states in the soil caused by different growth seasons on Cd uptake by rice remain unclear. In this study, three early rice cultivars and three late rice cultivars were cultivated in a double-cropping system in Cd-contaminated paddy fields. The total Cd accumulation of early rice cultivars was 20.5-51.1 mu g plant-1, and the Cd concentration in grains was 0.19-0.73 mg kg-1, significantly lower than those of late rice cultivars by 8-15 times and 3-9 times, respectively. The filling and mature stages were identified as the most crucial stages of Cd uptake by both early and late rice cultivars. The growth season of early rice cultivars was characterized by more abundant rainfall and lower soil Eh than that for late rice cultivars. Therefore, the abundances of Fe-reducing bacteria (FeRB, 36.9-39%) and S-reducing bacteria (SRB, 1.77-2.79%) were higher during the filling and mature stages of early rice. They primarily belonged to the Clostridium, Geobacter, and Desulfuromonadales genera. Stimulation of FeRB and SRB activity promoted Fe(III) and S reduction and increased the content of Fe2+ and S2- in rhizosphere soil. This promoted the binding of Cd to amorphous Fe oxides and sulfides or Fe sulfides, thereby decreasing the available Cd content. Moreover, the Cd in the iron plaque (IP) and Cd transfer from IP to roots were lower in early rice. These findings suggest that maintaining high moisture content in the soil during the filling and mature stages, especially for late rice cultivars, could efficiently reduce Cd uptake by rice planted in contaminated soil.