title: Growth inhibition and effect on photosystem by three imidazolium chloride ionic liquids in rice seedlings.
abstract: The effects of three imidazolium chloride ionic liquids (ILs) including 1-octyl-3-methylimidazolium chloride ionic liquid ([OMIM]Cl), 1-decyl-3-methylimidazolium chloride ionic liquid ([DMIM]Cl) and 1-dodecyl-3-methylimidazolium chloride ionic liquid ([C12MIM]Cl) were studied in hydroponically grown rice seedlings. The growth inhibition rate increased and the Hill reaction activity of isolated rice chloroplasts decreased with increasing ILs concentrations. The IC50,5d for stem length was 0.70 mg/L of [OMIM]Cl, 0.15 mg/L of [DMIM]Cl, and 0.055 mg/L of [C12MIM]Cl, respectively. The SOD, POD and CAT activities of chloroplast exhibited initial increases followed by decreases in activity with increasing ILs concentrations. Chlorophyll fluorescence parameters such as the maximum effective quantum yield of PSII(Fv/Fm), the potential activity of PSII(Fv/F0), the yield of photochemical quantum [Y(II)], the photochemical quenching coefficient (qP), the non-photochemical quenching coefficient (NPQ) and the relative electron transport ratio (rETR) were affected, showing that ILs will damage the PSII. The results demonstrated that imidazolium chloride ILs are phytotoxic to rice growth and their photosystem, the toxicity increased as the alkyl chain length increased with the following order: [OMIM]Cl<[DMIM]Cl<[C12MIM]Cl. The results will help to better understand the possible role of the defense mechanism in rice caused by ILs exposure.
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang Province, China. Electronic address: lhj@mail.zjgsu.edu.cn.
authors.forename: Huijun
authors.initials: H
authors.lastname: Liu
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang Province, China; Jiaxing University, Jiaxing 314001, Zhejiang Province, China.
authors.forename: Shuxian
authors.initials: S
authors.lastname: Zhang
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang Province, China.
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Zhang
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang Province, China.
authors.forename: Caidong
authors.initials: C
authors.lastname: Chen
mesh_terms: D002374:Catalase / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D002736:Chloroplasts / Q000187:drug effects / Q000378:metabolism; D007093:Imidazoles / Q000633:toxicity*; D052578:Ionic Liquids / Q000633:toxicity*; D012275:Oryza / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D018547:Plant Stems / Q000187:drug effects / Q000254:growth & development; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: C521425:1-dodecyl-3-methylimidazolium; C528768:1-octyl-3-methylimidazolium; D007093:Imidazoles; D052578:Ionic Liquids; D045332:Photosystem II Protein Complex; D002734:Chlorophyll; D002374:Catalase; D009195:Peroxidase; D013482:Superoxide Dismutase
keywords: Antioxidant enzyme activity; Chlorophyll fluorescence; Growth inhibition; Hill reaction activity; Imidazolium chloride ionic liquids