Nano-selenium controlled cadmium accumulation and improved photosynthesis in indica rice cultivated in lead and cadmium combined paddy soils  

作　　者：Chengrun Wang Tingting Cheng Haitao Liu Fangyun Zhou JifengZhang Min Zhang Xinya Liu Wenjun Shi Tong Cao 

机构地区：[1]School of Biological Engineering,Huainan Normal University,Huainan 232038,China [2]Key Laboratory of Bioresource and Environmental Biotechnology of Anhui Higher Education Institutes,Huainan Normal University,Huainan 232038,China

出　　处：《Journal of Environmental Sciences》2021年第5期336-346,共11页环境科学学报（英文版）

基　　金：supported by the Major Project of Science and Technology of Anhui Province(No.18030701189)。

摘　　要：Selenium nanoparticles(Se NPs) are less toxic and more biocompatible than selenite or selenate. However, studies involving spraying with Se NPs for reducing accumulation of cadmium(Cd) and lead(Pb) in rice grains have been rarely reported as yet. Herein, indica rice seedlings cultivated in Cd + Pb-spiked paddy soils(denoted as positive control) were sprayed with Se NPs sols for four times from tillering to booting stage. Compared to positive control, 50–100 μmol/L Se NPs downregulated Cd transporters-related genes such as Os LCT 1, OsH MA 2 and Os CCX2 in leaves and OsLCT1, Os PCR1 and Os CCX2 genes in node I at filling stage. Meanwhile, Se-binding protein 1 was distinctly elevated, involving the repression of Cd and Pb transportation to rice grains. Se NPs also differentially improved RuBP carboxylase and chlorophylls especially some key genes and proteins involving photosynthetic system. Besides, 25–50 μmol/L Se NPs diminished reactive oxygen species overproduction from NADPH oxidases whereas boosted glutathione peroxidase, reducing protein carbonylation in rice seedlings. However, the antioxidant isozymes and oxidatively modified proteins were slightly rebounded at 100 μmol/L. Se contents were noticeably elevated and confirmed to exist as selenomethionine in the rice grains following all the treatments by Se NPs. Thus, the optimal dosage of Se NPs for foliar application is 50 μmol/L, which significantly decreased Cd accumulation, improved photosynthesis and Se enrichment whereas caused no distinct reduction of Pb in the grains. Thus, an appropriate dosage of Se NPs can be conducted to decrease Cd accumulation, improve photosynthesis, and organic Se contents in rice grains.

关 键 词：Selenium nanoparticles(Se NPs) Heavy metals Oryza sativa L. Selenium enrichment and cadmium reduction Food quality and safety 

分 类 号：X503.231[环境科学与工程—环境工程] S511.21[农业科学—作物学]