title: Regulation of photosynthetic performance and antioxidant capacity by ⁶⁰Co γ-irradiation in Zizania latifolia plants.
abstract: The aim of the present work was to investigate the photosynthetic performance and antioxidant enzyme activities in response to γ-irradiation of an aquatic plant Zizania latifolia. The Z. latifolia seedlings at 6-leaf stage were exposed to 25, 50 and 100 Gy of γ rays from a (60)Co source. The growth parameters, chlorophyll contents, photosynthetic gas exchange, chlorophyll fluorescence, malondialdehyde (MDA) content, antioxidant enzyme activities and antioxidant contents were examined at 1-5 weeks post-irradiation (WPI). The results showed that plant height, leaf number and tiller (branch close to ground) number were significantly suppressed by 50 and 100 Gy irradiation at 5, 3-5 and 4-5 WPI, respectively, but they were not significantly different from control by 25 Gy irradiation. Chlorophyll a, chlorophyll b, and total chlorophyll contents were also found to be significantly decreased by irradiation. The net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr) generally declined in a dose-dependent manner. As for the chlorophyll fluorescence parameters, maximum quantum efficiency of PSII photochemistry (Fv/Fm), actual photochemical efficiency of PSII (Φ(PSII)) and photochemical quenching (qP) were observed to be significantly decreased compared to the control at 3 WPI, while non-photochemical quenching (NPQ) significantly increased by 100 Gy. γ-irradiation induced substantial increase in MDA content, ascorbate peroxidase (APX) activity, reduced ascorbate (AsA) content and reduced glutathione (GSH) content, suggesting a protective mechanism of Z. latifolia plant against oxidative stress when exposed to γ-irradiation.
authors.affiliation: Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Fan
authors.affiliation: Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou 310029, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Shi
authors.affiliation: Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou 310029, PR China. Electronic address: jzhuang@zju.edu.cn.
authors.forename: Jian-Zhong
authors.initials: JZ
authors.lastname: Huang
authors.affiliation: Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Zhi-Dan
authors.initials: ZD
authors.lastname: Wang
authors.affiliation: Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, PR China. Electronic address: dpguo@zju.edu.cn.
authors.forename: De-Ping
authors.initials: DP
authors.lastname: Guo
mesh_terms: D001205:Ascorbic Acid / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D003037:Cobalt Radioisotopes / Q000633:toxicity*; D005720:Gamma Rays / Q000009:adverse effects*; D005978:Glutathione / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D010544:Peroxidases / Q000378:metabolism; D010788:Photosynthesis / Q000528:radiation effects; D045332:Photosystem II Protein Complex / Q000378:metabolism; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects; D006109:Poaceae / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D003037:Cobalt Radioisotopes; D045332:Photosystem II Protein Complex; D002734:Chlorophyll; D008315:Malondialdehyde; D010544:Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase; D005978:Glutathione; D001205:Ascorbic Acid
keywords: Antioxidant enzyme; Chlorophyll fluorescence; Photosynthesis; Zizania latifolia; γ-irradiation