title: Toxic effects of 1,4-dichlorobenzene on photosynthesis in Chlorella pyrenoidosa.
abstract: 1,4-Dichlorobenzene (1,4-DCB) is a common organic contaminant in water. To determine the effects of this contaminant on photosynthesis in the freshwater alga Chlorella pyrenoidosa, algal cells were treated with 1,4-DCB at different concentrations for various times, and their photosynthetic pigment contents and chlorophyll fluorescence traits were analyzed. The results showed that 1,4-DCB exerted toxic effects on photosynthesis in C. pyrenoidosa, especially at concentrations exceeding 10 mg/L. The inhibitory effects of 1,4-DCB were time- and concentration-dependent. After treatment with 1,4-DCB (≥10 mg/L), the contents of photosynthetic pigments decreased significantly, the photosystem II reaction center was irreversibly damaged, and the quantum yield of photosystem II decreased significantly. Also, there were sharp decreases in the efficiency of photosynthetic electron transport and energy conversion. Photosystem II became overloaded as the amount of excitation energy distributed to it increased. All of these events weakened the photochemical reaction, and ultimately led to serious inhibition of photosynthesis.
authors.affiliation: School of Life Science, Shanxi University, Taiyuan, China.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Life Science, Shanxi University, Taiyuan, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.affiliation: School of Life Science, Shanxi University, Taiyuan, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Feng
authors.affiliation: School of Life Science, Shanxi University, Taiyuan, China.
authors.forename: Junping
authors.initials: J
authors.lastname: Lv
authors.affiliation: Institute of Applied Chemistry, Shanxi University, Taiyuan, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Cai
authors.affiliation: School of Life Science, Shanxi University, Taiyuan, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Liu
authors.affiliation: School of Life Science, Shanxi University, Taiyuan, China. xiesl@sxu.edu.cn.
authors.forename: Shulian
authors.initials: S
authors.lastname: Xie
mesh_terms: D002708:Chlorella / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D002722:Chlorobenzenes / Q000633:toxicity*; D002734:Chlorophyll / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004579:Electron Transport / Q000187:drug effects; D004784:Environmental Monitoring / Q000379:methods*; D010788:Photosynthesis / Q000187:drug effects*; D045332:Photosystem II Protein Complex / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D002722:Chlorobenzenes; D045332:Photosystem II Protein Complex; D014874:Water Pollutants, Chemical; D002734:Chlorophyll; C018511:4-dichlorobenzene
keywords: 1,4-dichlorobenzene; Chlorella pyrenoidosa; Photosynthesis; Toxic effect