title: Combined effects of lanthanum (III) chloride and acid rain on photosynthetic parameters in rice.
abstract: Rare earth elements (REEs) pollution and acid rain are environmental issues, and their deleterious effects on plants attract worldwide attention. These two issues exist simultaneously in many regions, especially in some rice-growing areas. However, little is known about the combined effects of REEs and acid rain on plants. Here, the combined effects of lanthanum chloride (LaCl3), one type of REE salt, and acid rain on photosynthesis in rice were investigated. We showed that the combined treatment of 81.6 μM LaCl3 and acid rain at pH 4.5 increased net photosynthetic rate (Pn), stomatic conductance (Gs), intercellular CO2 concentration (Ci), Hill reaction activity (HRA), apparent quantum yield (AQY) and carboxylation efficiency (CE) in rice. The combined treatment of 81.6 μM LaCl3 and acid rain at pH 3.5 began to behave toxic effects on photosynthesis (decreasing Pn, Gs, HRA, AQY and CE, and increasing Ci), and the maximally toxic effects were observed in the combined treatment of 2449.0 μM LaCl3 and acid rain at pH 2.5. Moreover, the combined effects of LaCl3 and acid rain on photosynthesis in rice depended on the growth stage of rice, with the maximal effects occurring at the booting stage. Furthermore, the combined treatment of high-concentration LaCl3 and low-pH acid rain had more serious effects on photosynthesis in rice than LaCl3 or acid rain treatment alone. Finally, the combined effect of LaCl3 and acid rain on Pn in rice resulted from the changes in stomatic (Gs, Ci) and non-stomatic (HRA, AQY and CE) factors.
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, China.
authors.forename: Lihong
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, 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 / Q000633:toxicity*; D002245:Carbon Dioxide / Q000378:metabolism; D004347:Drug Interactions; D004785:Environmental Pollutants / Q000633:toxicity*; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D063427:Food Quality; D059022:Food Safety; D007811:Lanthanum / Q000633:toxicity*; D012275:Oryza / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism*; D010788:Photosynthesis / Q000187:drug effects*; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development
chemical_list: D015258:Acid Rain; D004785:Environmental Pollutants; C028521:lanthanum chloride; D002245:Carbon Dioxide; D007811:Lanthanum
keywords: Acid rain; Combined pollution; Growth stage; Lanthanum; Photosynthesis; Rice