title: Exogenous calcium induces tolerance to atrazine stress in Pennisetum seedlings and promotes photosynthetic activity, antioxidant enzymes and psbA gene transcripts.
abstract: Calcium (Ca) has been reported to lessen oxidative damages in plants by upregulating the activities of antioxidant enzymes. However, atrazine mediated reactive oxygen species (ROS) reduction by Ca is limited. This study therefore investigated the effect of exogenously applied Ca on ROS, antioxidants activity and gene transcripts, the D1 protein (psbA gene), and chlorophyll contents in Pennisetum seedlings pre-treated with atrazine. Atrazine toxicity increased ROS production and enzyme activities (ascorbate peroxidase APX, peroxidase POD, Superoxide dismutase SOD, glutathione-S-transferase GST); but decreased antioxidants (APX, POD, and Cu/Zn SOD) and psbA gene transcripts. Atrazine also decreased the chlorophyll contents, but increased chlorophyll (a/b) ratio. Contrarily, Ca application to atrazine pre-treated seedlings lowered the harmful effects of atrazine by reducing ROS levels, but enhancing the accumulation of total chlorophyll contents. Ca-protected seedlings in the presence of atrazine manifested reduced APX and POD activity, whereas SOD and GST activity was further increased with Ca application. Antioxidant gene transcripts that were down-regulated by atrazine toxicity were up-regulated with the application of Ca. Calcium application also resulted in up-regulation of the D1 protein. In conclusion, ability of calcium to reverse atrazine-induced oxidative damage and calcium regulatory role on GST in Pennisetum was presented.
authors.affiliation: School of Resources & Environment, Northeast Agricultural University, Harbin 150030, PR China.
authors.forename: Kehinde Olajide
authors.initials: KO
authors.lastname: Erinle
authors.affiliation: School of Resources & Environment, Northeast Agricultural University, Harbin 150030, PR China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: School of Resources & Environment, Northeast Agricultural University, Harbin 150030, PR China.
authors.forename: Bingbing
authors.initials: B
authors.lastname: Ma
authors.affiliation: School of Resources & Environment, Northeast Agricultural University, Harbin 150030, PR China.
authors.forename: Jinmei
authors.initials: J
authors.lastname: Li
authors.affiliation: School of Resources & Environment, Northeast Agricultural University, Harbin 150030, PR China.
authors.forename: Yukun
authors.initials: Y
authors.lastname: Chen
authors.affiliation: School of Resources & Environment, Northeast Agricultural University, Harbin 150030, PR China.
authors.forename: Khalil
authors.initials: K
authors.lastname: Ur-Rehman
authors.affiliation: School of Resources & Environment, Northeast Agricultural University, Harbin 150030, PR China.
authors.forename: Andleeb
authors.initials: A
authors.lastname: Shahla
authors.affiliation: School of Resources & Environment, Northeast Agricultural University, Harbin 150030, PR China. Electronic address: zhangyinghr@hotmail.com.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D060387:Ascorbate Peroxidases / Q000378:metabolism; D001280:Atrazine / Q000378:metabolism / Q000633:toxicity*; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology*; D002734:Chlorophyll / Q000031:analogs & derivatives / Q000378:metabolism; D000077194:Chlorophyll A; D006540:Herbicides / Q000633:toxicity*; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D031782:Pennisetum / Q000187:drug effects* / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D010544:Peroxidases / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects; D013482:Superoxide Dismutase / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D000975:Antioxidants; D006540:Herbicides; D017382:Reactive Oxygen Species; D002734:Chlorophyll; C085815:chlorophyll a'; D010544:Peroxidases; D060387:Ascorbate Peroxidases; D009195:Peroxidase; D013482:Superoxide Dismutase; D001280:Atrazine; D002118:Calcium; D000077194:Chlorophyll A
keywords: Atrazine; Calcium; Photosynthesis; Phytotoxicity; psbA gene