Uniconazole, as a plant growth retardant, can enhance stress tolerance in plants, possibly because of improved antioxidation defense mechanisms with higher activities of superoxide dismutase(SOD) and peroxidase(POD) e...Uniconazole, as a plant growth retardant, can enhance stress tolerance in plants, possibly because of improved antioxidation defense mechanisms with higher activities of superoxide dismutase(SOD) and peroxidase(POD) enzymes that retard lipid peroxidation and membrane deterioration. These years much attention has been focused on the responses of antioxidant system in plants to uniconazole stress, but such studies on aquatic organism are very few. Moreover, no information is available on growth and antioxidant response in marine microalgae to uniconazole. In this paper, the growth and antioxidant responses of two marine microalgal species, Platymonas helgolandica and Pavlova viridis, at six uniconazole concentrations(0-15 mg L-1) were investigated. The results demonstrated that 3 mg L-1 uniconazole could increase significantly chlorophyll a and carbohydrate contents of P. helgolandica(P < 0.05). Higher concentrations(≥12 mg L-1) of uniconazole could inhibit significantly the growth, dry weight, chlorophyll-a and carbohydrate contents of P. helgolandica and P. viridis(P < 0.05). Uniconazole caused a significant increase in lipid peroxidation production(MDA) at higher concentrations(≥ 9 mg L-1). The activities of antioxidant enzymes, superoxide dismutase(SOD) and catalase(CAT) were enhanced remarkably at low concentrations of uniconazole. However, significant reduction of SOD and CAT activities was observed at higher concentrations of uniconazole.展开更多
Three treatments consisting of 0%,15%,and 30%seawater were investigated to analyse the ecotypic variabilities among five populations of Jerusalem artichoke(Helianthus tuberosus)regarding their responses to seawater st...Three treatments consisting of 0%,15%,and 30%seawater were investigated to analyse the ecotypic variabilities among five populations of Jerusalem artichoke(Helianthus tuberosus)regarding their responses to seawater stress under a hydroponic culture system.Analyses were done 2,4,and 6 days after treatments.The 15%and 30%seawater treatments reduced the growth rates of roots and shoots of H.tuberosus populations.The activities of superoxide dismutase, peroxidase,and catalase majored in the leaves were stimulated under the seawater stress.The electrolyte leakage and malondialdehyde contents of the leaves were also stimulated owing to seawater stress.The contents of proline and soluble- sugars in the leaves increased significantly with increasing seawater concentrations.The concentrations of Na+,K+,and Cl-in the aerial parts and roots increased with an increase in the seawater concentration throughout the experimental period.There were ecotypic differences among the five populations of H.tuberosus as evidenced by the analyses of the above items in both aerial parts and roots under seawater treatment.The magnitude of the ecotypic variance components indicated that a substantial proportion of the total variation for these physiological and biochemical responses were owing to ecotype,indicating the possibility of improvement through hybridization and selection.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 21071133, 51273184 and 81202399)the Program for Science and Technology of Shandong Province (2011GHY11521)the Natural Science Foundation of Qingdao City (Nos. 11-2-4-1-(9) gch), 12-1-3-52-(1)-nsh and 12-1-4-16-(7)-jch)
文摘Uniconazole, as a plant growth retardant, can enhance stress tolerance in plants, possibly because of improved antioxidation defense mechanisms with higher activities of superoxide dismutase(SOD) and peroxidase(POD) enzymes that retard lipid peroxidation and membrane deterioration. These years much attention has been focused on the responses of antioxidant system in plants to uniconazole stress, but such studies on aquatic organism are very few. Moreover, no information is available on growth and antioxidant response in marine microalgae to uniconazole. In this paper, the growth and antioxidant responses of two marine microalgal species, Platymonas helgolandica and Pavlova viridis, at six uniconazole concentrations(0-15 mg L-1) were investigated. The results demonstrated that 3 mg L-1 uniconazole could increase significantly chlorophyll a and carbohydrate contents of P. helgolandica(P < 0.05). Higher concentrations(≥12 mg L-1) of uniconazole could inhibit significantly the growth, dry weight, chlorophyll-a and carbohydrate contents of P. helgolandica and P. viridis(P < 0.05). Uniconazole caused a significant increase in lipid peroxidation production(MDA) at higher concentrations(≥ 9 mg L-1). The activities of antioxidant enzymes, superoxide dismutase(SOD) and catalase(CAT) were enhanced remarkably at low concentrations of uniconazole. However, significant reduction of SOD and CAT activities was observed at higher concentrations of uniconazole.
基金Project Supported by the National Key Project of Scientific and Technical Supporting Programs Funded by Ministry of Science&Technology of China(Nos.2006BAD09A08-03-01 and 2006BAD09A04-05)the National High Technology Research and Development Program(863 Program)of China(No.2007AA091702)the Opening Program of Jiangsu Provincial Key Laboratory of Coastal Wetland Bio-resource and Environmental Protection(JLCBE)(No.JLCBE07001)
文摘Three treatments consisting of 0%,15%,and 30%seawater were investigated to analyse the ecotypic variabilities among five populations of Jerusalem artichoke(Helianthus tuberosus)regarding their responses to seawater stress under a hydroponic culture system.Analyses were done 2,4,and 6 days after treatments.The 15%and 30%seawater treatments reduced the growth rates of roots and shoots of H.tuberosus populations.The activities of superoxide dismutase, peroxidase,and catalase majored in the leaves were stimulated under the seawater stress.The electrolyte leakage and malondialdehyde contents of the leaves were also stimulated owing to seawater stress.The contents of proline and soluble- sugars in the leaves increased significantly with increasing seawater concentrations.The concentrations of Na+,K+,and Cl-in the aerial parts and roots increased with an increase in the seawater concentration throughout the experimental period.There were ecotypic differences among the five populations of H.tuberosus as evidenced by the analyses of the above items in both aerial parts and roots under seawater treatment.The magnitude of the ecotypic variance components indicated that a substantial proportion of the total variation for these physiological and biochemical responses were owing to ecotype,indicating the possibility of improvement through hybridization and selection.
