The dependence of energy metabolism on temperature is universally recognized as a critical physiological hallmark for evaluating the susceptibility of ectothermic organisms to global warming.However,the underlying phy...The dependence of energy metabolism on temperature is universally recognized as a critical physiological hallmark for evaluating the susceptibility of ectothermic organisms to global warming.However,the underlying physiological and biochemical bases of this temperature dependence remain largely unknown.In this study,we conducted a simulated climate warming experiment under seminatural enclosure conditions and compared the differences in resting metabolic rate (RMR) and key metabolic enzyme activities between the warming and control groups of Takydromus septentrionalis at various test temperatures.We found that the activities of hexokinase,lactate dehydrogenase,alanine aminotransferase and acetyl-CoA carboxylase of T.septentrionalis were not affected by climate warming,despite a decrease in RMR measured at high temperatures of 34°C and 38°C.Overall,these findings suggest that artificial warming simulating climate change can lead to a decline in RMR,but does not alter the activity of key metabolic enzymes.Our study provides insight into how climate warming influences the energy metabolism of lizards.展开更多
Global climate changes have increased temperatures,radiation indexes,and consequently,irregularities in rainfall in mainly tropical countries,considerably hindering plant establishment in recovering degraded areas.The...Global climate changes have increased temperatures,radiation indexes,and consequently,irregularities in rainfall in mainly tropical countries,considerably hindering plant establishment in recovering degraded areas.The objective of this study was to evaluate the growth and physiological characteristics of one species of each successional group:pioneer,secondary,and climax when subjected to different light intensities and hydrogel as a soil conditioner during rainy and dry periods.The experiment was conducted in the ecotone between Brazil’s two largest biomes,the Cerrado and the Amazon in the State of Maranh?o.The parameters consisted of three species:Guazuma ulmifolia Lam.(pioneer),Astronium fraxinifolium Schott(secondary),and Cariniana rubra Gardner ex Miers(climax).There were two light intensities:70%and 100%,and two planting conditions:with and without soil conditioner(hydrogel).Gas exchanges were higher during the rainy season;the pioneer and secondary species had greater heights and photosynthetic rates in the dry period;the climax species had the lowest gas exchange and lowest recovery as rainfall resumed.The pioneer and secondary species showed higher physiological plasticity,denoting better adaption to environments with high irradiance.Hydrogel improved the photosynthetic performance of these species in the dry season and in areas with 100%sunlight.展开更多
Adaptation along environmental gradients is presumed to induce physiological and biochemical leaf changes in plant species. In this paper, we report how leaf gas exchange, photon capture and light harvest for photosyn...Adaptation along environmental gradients is presumed to induce physiological and biochemical leaf changes in plant species. In this paper, we report how leaf gas exchange, photon capture and light harvest for photosynthesis in Aldina heterophylla change along a vegetation gradient from low stature open vegetation on extremely nutrient-poor white sand (Campina, CP), through inter-mediate closet type (Campinarana, CR) to tall closed rain forest (RF). The pigment concentrations did not differ between the CP, CR and RF habitats. The performance index for the photosynthesis (PIABS) of individuals in RF and CP was approximately 30% higher than that in CR individuals. This species showed similar potential rates of photosynthesis in the different vegetation types;however, the dark respiration rates were higher in CP. Our results indicate that the differences in the leaves and soil nitrogen concentrations are not enough to change the levels of gas exchange. Other environmental features may be driving the observed morphological features in this gradient, in particular, the tree height.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.32330067,31971419,32311530110,and 32171486)。
文摘The dependence of energy metabolism on temperature is universally recognized as a critical physiological hallmark for evaluating the susceptibility of ectothermic organisms to global warming.However,the underlying physiological and biochemical bases of this temperature dependence remain largely unknown.In this study,we conducted a simulated climate warming experiment under seminatural enclosure conditions and compared the differences in resting metabolic rate (RMR) and key metabolic enzyme activities between the warming and control groups of Takydromus septentrionalis at various test temperatures.We found that the activities of hexokinase,lactate dehydrogenase,alanine aminotransferase and acetyl-CoA carboxylase of T.septentrionalis were not affected by climate warming,despite a decrease in RMR measured at high temperatures of 34°C and 38°C.Overall,these findings suggest that artificial warming simulating climate change can lead to a decline in RMR,but does not alter the activity of key metabolic enzymes.Our study provides insight into how climate warming influences the energy metabolism of lizards.
文摘Global climate changes have increased temperatures,radiation indexes,and consequently,irregularities in rainfall in mainly tropical countries,considerably hindering plant establishment in recovering degraded areas.The objective of this study was to evaluate the growth and physiological characteristics of one species of each successional group:pioneer,secondary,and climax when subjected to different light intensities and hydrogel as a soil conditioner during rainy and dry periods.The experiment was conducted in the ecotone between Brazil’s two largest biomes,the Cerrado and the Amazon in the State of Maranh?o.The parameters consisted of three species:Guazuma ulmifolia Lam.(pioneer),Astronium fraxinifolium Schott(secondary),and Cariniana rubra Gardner ex Miers(climax).There were two light intensities:70%and 100%,and two planting conditions:with and without soil conditioner(hydrogel).Gas exchanges were higher during the rainy season;the pioneer and secondary species had greater heights and photosynthetic rates in the dry period;the climax species had the lowest gas exchange and lowest recovery as rainfall resumed.The pioneer and secondary species showed higher physiological plasticity,denoting better adaption to environments with high irradiance.Hydrogel improved the photosynthetic performance of these species in the dry season and in areas with 100%sunlight.
基金The authors thank the members of the Laboratory of Plant Physiology and Biochemistry for their help in implementing the field work and scientific contributionsthe LBA Project for logistical supportTrace Misiewicz for suggestions and CNPq for a scholarship and financial support.
文摘Adaptation along environmental gradients is presumed to induce physiological and biochemical leaf changes in plant species. In this paper, we report how leaf gas exchange, photon capture and light harvest for photosynthesis in Aldina heterophylla change along a vegetation gradient from low stature open vegetation on extremely nutrient-poor white sand (Campina, CP), through inter-mediate closet type (Campinarana, CR) to tall closed rain forest (RF). The pigment concentrations did not differ between the CP, CR and RF habitats. The performance index for the photosynthesis (PIABS) of individuals in RF and CP was approximately 30% higher than that in CR individuals. This species showed similar potential rates of photosynthesis in the different vegetation types;however, the dark respiration rates were higher in CP. Our results indicate that the differences in the leaves and soil nitrogen concentrations are not enough to change the levels of gas exchange. Other environmental features may be driving the observed morphological features in this gradient, in particular, the tree height.
