The physiological responses of Paspalum vaginatum Sw. to Cd stress and its Cd accumulation characteristics were studied by investigating the effects of different concentrations of Cd on the growth, root vigor, leaf me...The physiological responses of Paspalum vaginatum Sw. to Cd stress and its Cd accumulation characteristics were studied by investigating the effects of different concentrations of Cd on the growth, root vigor, leaf membrane permeability, membrane lipid peroxidation, protective enzyme activity and Cd accumulation of P. vaginatum. When the Cd concentration was over 50.00 mg/kg, with the increased Cd concentration, the CAT activity declined significantly, the synergistic effect between SOD and CAT was weakened, the MDA content increased greatly, and the root vigor decreased, leading to inhibited growth of P. vaginatum. When the Cd concentration was in the range of 0-50 mg/kg, the root vigor of P. vaginatum did not decline obviously, the activity of protective enzymes （SOD and CAT） was enhanced, and the MDA accumulation and cell membrane permeability did not increase significantly, thus the damage of Cd to P. vaginatum was lighter. Roots of P. vaginatum showed strong enrichment capacity for Cd. When the Cd concentration was up to 200.00 mg/kg, the Cd contents in shoot and root of P. vaginatum reached 39.15 and 1 097.38 mg/kg, respectively. It suggests that in the concentration range of 0-50.00 mg/kg, P. vaginatum can make effective responses to Cd stress and grow normally, and it can be planted as a candidate material to remediate Cd-contaminated soil.展开更多
The response of plant leaf and root phenology and biomass in the Arctic to global change remains unclear due to the lack of synchronous measurements of above-and belowground parts.Our objective was to determine the ph...The response of plant leaf and root phenology and biomass in the Arctic to global change remains unclear due to the lack of synchronous measurements of above-and belowground parts.Our objective was to determine the phenological dynamics of the above-and belowground parts of Eriophorum vaginatum in the Arctic and its response to warming.We established a common garden located at Toolik Lake Field Station;tussocks of E.vaginatum from three locations,Coldfoot,Toolik Lake and Sagwon,were transplanted into the common garden.Control and warming treatments for E.vaginatum were set up at the Toolik Lake during the growing seasons of 2016 and 2017.Digital cameras,a handheld sensor and minirhizotrons were used to simultaneously observe leaf greenness,normalized difference vegetation index and root length dynamics,respectively.Leaf and root growth rates of E.vaginatum were asynchronous such that the timing of maximal leaf growth(mid-july)was about 28 days earlier than that of root growth.Warming of air temperature by 1°C delayed the timing of leaf senescence and thus prolonged the growing season,but the temperature increase had no significant effect on root phenology.The seasonal dynamics of leaf biomass were affected by air temperature,whereas root biomass was correlated with soil thaw depth.Therefore,we suggest that leaf and root components should be considered comprehensively when using carbon and nutrient cycle models,as above-and belowground productivity and functional traits may have a different response to climate warming.展开更多
文摘The physiological responses of Paspalum vaginatum Sw. to Cd stress and its Cd accumulation characteristics were studied by investigating the effects of different concentrations of Cd on the growth, root vigor, leaf membrane permeability, membrane lipid peroxidation, protective enzyme activity and Cd accumulation of P. vaginatum. When the Cd concentration was over 50.00 mg/kg, with the increased Cd concentration, the CAT activity declined significantly, the synergistic effect between SOD and CAT was weakened, the MDA content increased greatly, and the root vigor decreased, leading to inhibited growth of P. vaginatum. When the Cd concentration was in the range of 0-50 mg/kg, the root vigor of P. vaginatum did not decline obviously, the activity of protective enzymes （SOD and CAT） was enhanced, and the MDA accumulation and cell membrane permeability did not increase significantly, thus the damage of Cd to P. vaginatum was lighter. Roots of P. vaginatum showed strong enrichment capacity for Cd. When the Cd concentration was up to 200.00 mg/kg, the Cd contents in shoot and root of P. vaginatum reached 39.15 and 1 097.38 mg/kg, respectively. It suggests that in the concentration range of 0-50.00 mg/kg, P. vaginatum can make effective responses to Cd stress and grow normally, and it can be planted as a candidate material to remediate Cd-contaminated soil.
基金the Office of Polar Programs(National Science Foundation)(1417763 to J.T.,1418010 to N.F.and 1417645 to M.L.M.).
文摘The response of plant leaf and root phenology and biomass in the Arctic to global change remains unclear due to the lack of synchronous measurements of above-and belowground parts.Our objective was to determine the phenological dynamics of the above-and belowground parts of Eriophorum vaginatum in the Arctic and its response to warming.We established a common garden located at Toolik Lake Field Station;tussocks of E.vaginatum from three locations,Coldfoot,Toolik Lake and Sagwon,were transplanted into the common garden.Control and warming treatments for E.vaginatum were set up at the Toolik Lake during the growing seasons of 2016 and 2017.Digital cameras,a handheld sensor and minirhizotrons were used to simultaneously observe leaf greenness,normalized difference vegetation index and root length dynamics,respectively.Leaf and root growth rates of E.vaginatum were asynchronous such that the timing of maximal leaf growth(mid-july)was about 28 days earlier than that of root growth.Warming of air temperature by 1°C delayed the timing of leaf senescence and thus prolonged the growing season,but the temperature increase had no significant effect on root phenology.The seasonal dynamics of leaf biomass were affected by air temperature,whereas root biomass was correlated with soil thaw depth.Therefore,we suggest that leaf and root components should be considered comprehensively when using carbon and nutrient cycle models,as above-and belowground productivity and functional traits may have a different response to climate warming.
