title: Analysis of the combined effects of lanthanum and acid rain, and their mechanisms, on nitrate reductase transcription in plants.
abstract: Rare earth element (REE) pollution and acid rain are major global environmental concerns, and their spatial distributions overlap. Thus, both forms of pollution combine to act on plants. Nitrogen is important for plant growth, and nitrate reductase (NR) is a key plant enzyme that catalyzes nitrogen assimilation. Studying the combined effects of REEs and acid rain on plant nitrogen-based nutrients has important environmental significance. Here, soybean (Glycine max) plants, commonly used for toxicological studies, were exposed to lanthanum (La), a REE, and acid rain to study the NR activities and NR transcriptional levels in the roots. To explain how the pollution affected the NR transcriptional level, we simultaneously observed the contents of intracellular La and nutrient elements, protoplast morphology, membrane lipid peroxidation and intracellular pH. A combined treatment of 0.08mmol/L La and pH 4.5 acid rain increased the NR activity, decreased the NR transcriptional level, increased the intracellular nutrient elements' contents and caused deformations in membrane structures. Other combined treatments significantly decreased the aforementioned parameters and caused serious damage to the membrane structures. The variation in the amplitudes of combined treatments was greater than those of individual treatments. Compared with the control and individual treatments, combined treatments increased membrane permeability, the malondialdehyde content, and intracellular H+and La contents, and with an increasing La concentration or acid strength, the change in amplitude increased. Thus, the combined effects on NR gene transcription in soybean seedling roots were related to the intracellular nutrient elements' contents, protoplast morphology, membranous lipid peroxidation, intracellular pH and La content.
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangsu Key Laboratory of Anaerobic Biotechnology, College of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China; Jiangsu Cooperative Innovation Center of Water Treatment Technology and Materials, Suzhou University of Science and Technology, Suzhou 215009, China.
authors.forename: Binxin
authors.initials: B
authors.lastname: Xia
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangsu Key Laboratory of Anaerobic Biotechnology, College of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China; Jiangsu Cooperative Innovation Center of Water Treatment Technology and Materials, Suzhou University of Science and Technology, Suzhou 215009, China.
authors.forename: Zhaoguo
authors.initials: Z
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangsu Key Laboratory of Anaerobic Biotechnology, College of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China; Jiangsu Cooperative Innovation Center of Water Treatment Technology and Materials, Suzhou University of Science and Technology, Suzhou 215009, China.
authors.forename: Lihong
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangsu Key Laboratory of Anaerobic Biotechnology, College of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China; Jiangsu Cooperative Innovation Center of Water Treatment Technology and Materials, Suzhou University of Science and Technology, Suzhou 215009, China. Electronic address: qingzhou510@yahoo.com.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, Jiangsu Key Laboratory of Biomedical Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210046, China. Electronic address: huangxiaohuanjnu@yahoo.com.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Huang
mesh_terms: D015258:Acid Rain / Q000009:adverse effects*; D002462:Cell Membrane / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007811:Lanthanum / Q000378:metabolism / Q000494:pharmacology*; D015227:Lipid Peroxidation; D008315:Malondialdehyde / Q000378:metabolism; D008563:Membrane Lipids / Q000378:metabolism; D050901:Nitrate Reductase / Q000235:genetics / Q000378:metabolism*; D010539:Permeability; D018517:Plant Roots / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D011523:Protoplasts / Q000187:drug effects / Q000473:pathology; D036226:Seedlings / Q000187:drug effects / Q000201:enzymology; D013025:Glycine max / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D015258:Acid Rain; D008563:Membrane Lipids; D008315:Malondialdehyde; D007811:Lanthanum; D050901:Nitrate Reductase
keywords: Acid rain; Combined effects; Gene transcription; Lanthanum; Nitrate reductase; Plant roots