scholarly journals Photosynthetic responses of Halimeda scabra (Chlorophyta, Bryopsidales) to interactive effects of temperature, pH, and nutrients and its carbon pathways

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10958
Author(s):  
Daily Zuñiga-Rios ◽  
Román Manuel Vásquez-Elizondo ◽  
Edgar Caamal ◽  
Daniel Robledo
Keyword(s):  
Nutrient Enrichment ◽  
Photosynthetic Performance ◽  
Interactive Effects ◽  
Control Treatment ◽  
Effect Of Temperature ◽  
Carbon Stable Isotope ◽  
Gross Photosynthesis ◽  
Photosynthesis Inhibition ◽  
Effects Of Temperature ◽  
Photosynthetic Responses

In this study, we evaluated the interactive effects of temperature, pH, and nutrients on photosynthetic performance in the calcareous tropical macroalga Halimeda scabra. A significant interaction among these factors on gross photosynthesis (Pgross) was found. The highest values of Pgross were reached at the highest temperature, pH, and nutrient enrichment tested and similarly in the control treatment (no added nutrients) at 33 °C at the lowest pH. The Q10 Pgross values confirmed the effect of temperature only under nutrient enrichment scenarios. Besides the above, bicarbonate (HCO3−) absorption was assessed by the content of carbon stable isotope (δ13C) in algae tissue and by its incorporation into photosynthetic products, as well as by carbonic anhydrase (CA) inhibitors (Acetazolamide, AZ and Ethoxyzolamide, EZ) assays. The labeling of δ13C revealed this species uses both, CO2 and HCO3− forms of Ci relying on a CO2 Concentration Mechanism (CCM). These results were validated by the EZ-AZ inhibition assays in which photosynthesis inhibition was observed, indicating the action of internal CA, whereas AZ inhibitor did not affect maximum photosynthesis (Pmax). The incorporation of 13C isotope into aspartate in light and dark treatments also confirmed photosynthetic and non-photosynthetic the HCO3−uptake.

Leaf structural responses to pre-industrial, current and elevated atmospheric [CO2] and temperature affect leaf function in Eucalyptus sideroxylon

2012 ◽  
Vol 39 (4) ◽  
pp. 285 ◽  
Author(s):  
Renee A. Smith ◽  
James D. Lewis ◽  
Oula Ghannoum ◽  
David T. Tissue
Keyword(s):  
Elevated Temperature ◽  
Photosynthetic Capacity ◽  
Leaf Structure ◽  
Atmospheric Co2 ◽  
Interactive Effects ◽  
Effect Of Temperature ◽  
Leaf Mass Per Area ◽  
Climate Change Research ◽  
Photosynthetic Responses ◽  
Eucalyptus Sideroxylon

Leaf structure and chemistry both play critical roles in regulating photosynthesis. Yet, a key unresolved issue in climate change research is the role of changes in leaf structure in photosynthetic responses to temperature and atmospheric CO2 concentration ([CO2]), ranging from pre-industrial to future levels. We examined the interactive effects of [CO2] (290, 400 and 650 μL L–1) and temperature (ambient, ambient +4°C) on leaf structural and chemical traits that regulate photosynthesis in Eucalyptus sideroxylon A.Cunn. ex Woolls. Rising [CO2] from pre-industrial to elevated levels increased light-saturated net photosynthetic rates (Asat), but reduced photosynthetic capacity (Amax). Changes in leaf N per unit area (Narea) and the number of palisade layers accounted for 56 and 14% of the variation in Amax, respectively, associated with changes in leaf mass per area. Elevated temperature increased stomatal frequency, but did not affect Amax. Further, rising [CO2] and temperature generally did not interactively affect leaf structure or function. These results suggest that leaf Narea and the number of palisade layers are the key chemical and structural factors regulating photosynthetic capacity of E. sideroxylon under rising [CO2], whereas the lack of photosynthetic responses to elevated temperature may reflect the limited effect of temperature on leaf structure and chemistry.

scholarly journals CO2 elevation improves photosynthetic performance in progressive warming environment in white birch seedlings

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 13 ◽  
Author(s):  
Shouren Zhang ◽  
Qing-Lai Dang
Keyword(s):  
Electron Transport ◽  
Electron Transport Rate ◽  
Global Climate ◽  
Photochemical Efficiency ◽  
Photosynthetic Performance ◽  
Transport Rate ◽  
Interactive Effects ◽  
Effect Of Temperature ◽  
White Birch

White birch (Betula paperifera Mash) seedlings were exposed to progressively warming in greenhouses under ambient and elevated CO2 concentrations for 5 months to explore boreal tree species’ potential capacity to acclimate to global climate warming and CO2 elevation. In situ foliar gas exchange, in vivo carboxylation characteristics and chlorophyll fluorescence were measured at temperatures of 26oC and 37oC. Elevated CO2 significantly increased net photosynthetic rate (Pn) at both measurement temperatures, and Pn at 37oC was higher than that at 26oC under elevated CO2. Stomatal conductance (gs) was lower at 37oC than at 26oC, while transpiration rate (E) was higher at 37oC than that at 26oC. Elevated CO2 significantly increased instantaneous water-use efficiency (WUE) at both 26oC and 37oC, but WUE was markedly enhanced at 37oC under elevated CO2. The effect of temperature on maximal carboxylation rate (Vcmax), PAR-saturated electron transport rate (Jmax) and triose phosphate utilization (TPU) varied with CO2, and the Vcmax and Jmax were significantly higher at 37oC than at 26oC under elevated CO2. However, there were no significant interactive effects of CO2 and temperature on TPU. The actual photochemical efficiency of PSII (DF/ Fm’), total photosynthetic linear electron transport rate through PSII (JT) and the partitioning of JT to carboxylation (Jc) were higher at 37oC than at 26oC under elevated CO2. Elevated CO2 significantly suppressed the partitioning of JT to oxygenation (Jo/JT). The data suggest that the CO2 elevation and progressive warming greatly enhanced photosynthesis in white birch seedlings in an interactive fashion.

Effect of temperature during the synthesis process of CdSe nanoparticles using the colloidal technique

MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3389-3395
Author(s):  
R. González-Díaz ◽  
D. Fernández-Sánchez ◽  
P. Rosendo-Francisco ◽  
G. Sánchez-Legorreta
Keyword(s):  
Scanning Tunneling Microscope ◽  
Electron Cloud ◽  
Cdse Nanoparticles ◽  
Effect Of Temperature ◽  
Synthesis Process ◽  
Scanning Tunneling ◽  
Tunneling Microscope ◽  
First Results ◽  
Effects Of Temperature ◽  
Scanning Electron

AbstractIn this work, the first results of the effects of temperature during the production of Se2- ions and the effect during the interaction of Cd2+ and Se2- ions in the synthesis process of CdSe nanoparticles are presented. The synthesis of CdSe was carried out by the colloidal technique, in the first one we used a temperature of 63 °C to produce Se2- ions and in the second one an interaction temperature of 49 °C. The samples were characterized using a Scanning Electron Microscope (SEM) and a Scanning Tunneling Microscope (STM). From the SEM micrographs it was possible to identify the thorns formation and irregular islands. STM micrographs reveal elliptical shapes with a regular electron cloud profile.

Interactive effects of temperature and redox on soil carbon and iron cycling

2021 ◽  
Vol 157 ◽  
pp. 108235
Author(s):  
Nikhil R. Chari ◽  
Yang Lin ◽  
Yuan S. Lin ◽  
Whendee L. Silver
Keyword(s):  
Soil Carbon ◽  
Interactive Effects ◽  
Iron Cycling ◽  
Effects Of Temperature

Use of a Modified Gompertz Equation to Predict the Effects of Temperature, pH, and NaCl on the Inactivation of Listeria monocytogenes Scott A Heated in Infant Formula

1996 ◽  
Vol 59 (1) ◽  
pp. 16-23 ◽  
Author(s):  
R. H. LINTON ◽  
W. H. CARTER ◽  
M. D. PIERSON ◽  
C. R. HACKNEY ◽  
J. D. EIFERT
Keyword(s):  
Listeria Monocytogenes ◽  
Infant Formula ◽  
Nonlinear Regression ◽  
Survival Curve ◽  
Interactive Effects ◽  
Parameter Estimates ◽  
Survival Curves ◽  
Gompertz Equation ◽  
Nacl Concentration ◽  
Effects Of Temperature

The heat resistance of Listeria monocytogenes was determined in infant formula for all possible combinations of temperature (50, 55, and 60°C), pH level (5, 6, and 7), and NaCl concentration (0, 2, and 4%). Survival curves were fit using nonlinear regression with a Gompertz equation. The Gompertz equation was flexible enough to fit the three most commonly observed survival curves: linear curves, those with an initial lag region followed by a linear region, and sigmoidal shaped. Parameter estimates obtained by the method of nonlinear least squares were used to describe the effect(s) of different heating treatments on the lag region, death rate, and tailing region of survival curves. These estimates were further used to predict single and interactive effects of temperature, pH, and percentage of NaCl on the log of the surviving fraction (LSF) of bacteria. Interactions among these variables significantly (P ≤ .05) affected the LSF. Generally, increased pH or NaCl concentration lead to an increased LSF, whereas increased time or temperature lead to a decreased LSF. All multiple-factor interactions significantly (P ≤ .05) affected the LSF. The correlation of observed LSF versus predicted LSF (R2 = .92) indicated that the estimated Gompertz equation was in close agreement with the observation. This study demonstrated that the Gompertz equation and nonlinear regression can be used as an effective means to predict survival curve shape and response to heat of L. monocytogenes under many different environmental conditions.

scholarly journals Interactive effects of climate and nutrient enrichment on patterns of herbivory by different feeding guilds in mangrove forests

2017 ◽  
Vol 26 (11) ◽  
pp. 1326-1338 ◽  
Author(s):  
Ilka C. Feller ◽  
Marilyn C. Ball ◽  
Joanne I. Ellis ◽  
Catherine E. Lovelock ◽  
Ruth Reef
Keyword(s):  
Nutrient Enrichment ◽  
Interactive Effects ◽  
Feeding Guilds ◽  
Mangrove Forests

scholarly journals The Effect of Temperature and Humidity May Reduce the Growth Rate of the Coronavirus Disease 2019 Epidemic

2020 ◽  
Author(s):  
Lei Qin ◽  
Qiang Sun ◽  
Jiani Shao ◽  
Yang Chen ◽  
Xiaomei Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Relative Humidity ◽  
Effect Of Temperature ◽  
Average Temperature ◽  
Temperature And Humidity ◽  
Scatter Plots ◽  
Low Humidity ◽  
Average Relative Humidity ◽  
Effects Of Temperature ◽  
The Relationship

Abstract Background: The effects of temperature and humidity on the epidemic growth of coronavirus disease 2019 (COVID-19)remains unclear.Methods: Daily scatter plots between the epidemic growth rate (GR) and average temperature (AT) or average relative humidity (ARH) were presented with curve fitting through the “loess” method. The heterogeneity across days and provinces were calculated to assess the necessity of using a longitudinal model. Fixed effect models with polynomial terms were developed to quantify the relationship between variations in the GR and AT or ARH.Results: An increased AT dramatically reduced the GR when the AT was lower than −5°C, the GR was moderately reduced when the AT ranged from −5°C to 15°C, and the GR increased when the AT exceeded 15°C. An increasedARH increased theGR when the ARH was lower than 72% and reduced theGR when the ARH exceeded 72%.Conclusions: High temperatures and low humidity may reduce the GR of the COVID-19 epidemic. The temperature and humidity curves were not linearly associated with the COVID-19 GR.

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