Effect of Temperature on Photoinhibition and Recovery in Actinidia deliciosa

1988 ◽  
Vol 15 (2) ◽  
pp. 195 ◽  
Author(s):  
DH Greer
Keyword(s):  
Light Exposure ◽  
Photochemical Reactions ◽  
High Light ◽  
Actinidia Deliciosa ◽  
Radiative Energy ◽  
Effect Of Temperature ◽  
Photoinhibition Of Photosynthesis ◽  
Temperature Dependent ◽  
Protection Mechanism ◽  
Kinetics Of

Photoinhibition of photosynthesis was induced in intact leaves of kiwifruit (Actinidia deliciosa) grown in natural light not exceeding a photon irradiance (PI) of 300 �mol m-2 s-1 by exposing them to a PI of 1500 �mol m-2 s-1. The temperature was held constant during the high-light exposure between 5 and 35°C. Recovery was followed at temperatures between 10 and 35°C, after photoinhibition was induced by a 240 min exposure to high light. The kinetics of photoinhibition and recovery were followed by chlorophyll fluorescence at 692 nm and 77K. Photoinhibition occurred at all temperatures but was greatest at low temperatures. Temperature affected the severity of photoinhibitory damage but not the kinetics of photoinhibition. Recovery was also temperature-dependent with little or no recovery occurring below about 20°C and rapid recovery at 30-35°C. The extent of photoinhibition also affected the rates of recovery which were reduced as the severity of photoinhibition increased. An analysis of the rate constants for energy transfer within photosystem II indicated that kiwifruit leaves have some capacity to prevent photoinhibition by increasing the amount of non-radiative energy dissipation. However, the analysis also indicates that this protection mechanism was not wholly effective since the primary photochemical reactions apparently become inactivated during exposure of these leaves to high light.

The Effect of Chloramphenicol on Photoinhibition of Photosynthesis and Its Recovery in Intact Kiwifruit (Actinidia deliciosa) Leaves

1993 ◽  
Vol 20 (1) ◽  
pp. 33 ◽  
Author(s):  
DH Greer ◽  
WA Laing ◽  
DJ Woolley
Keyword(s):  
Chlorophyll Fluorescence ◽  
Co2 Exchange ◽  
High Light ◽  
Actinidia Deliciosa ◽  
Thermal Dissipation ◽  
Radiative Energy ◽  
Minor Effect ◽  
Photoinhibition Of Photosynthesis ◽  
Fluorescence Measurements ◽  
Time Courses

Photoinhibition of photosynthesis in kiwifruit [Actinidia deliciosa (A. Chev.) C. F. Liang et A. R. Ferguson] leaves in high light and its subsequent recovery in low light was assessed in the presence of chloramphenicol (CAP), an inhibitor of chloroplast-encoded protein synthesis. Rooted cuttings were grown in a controlled environment at a photosynthetic irradiance of 700 μmol m-2 s-1 and a day/night temperature of 25/20�C. Time-courses of photoinhibition and recovery treatments were followed by measuring CO2 exchange and chlorophyll fluorescence at 77K and 692 nm. CAP both exacerbated photoinhibition and blocked recovery for at least 150 min, especially at high temperatures. The close conformation of these two effects affirm that photoinhibition and recovery occur concomitantly. There was no apparent effect of CAP on the xanthophyll cycle, either during photoinhibition or recovery, indicating that zeaxanthin-mediated non-radiative energy (thermal) dissipation was unaffected by CAP. Because the CAP-induced increase in photoinhibition was not matched by an increase in the ratio of zeaxanthin to violaxanthin and antheraxanthin, the capacity of this photoprotective mechanism was apparently saturated. The primary effect of CAP on chlorophyll fluorescence was to affect Fm, the maximum fluorescence. There was only a minor effect on the initial fluorescence, Fo, during the photoinhibition and recovery treatments. The calculation of the rate constants for non-radiative dissipation (kD) and photochemistry (kp) from the fluorescence measurements indicated that an increase in kD occurred during high-light exposures and this was stimulated by CAP. However, since zeaxanthin was not mediating this, an alternative quencher in kiwifruit leaves, perhaps damaged PSII centres, is proposed. This would be consistent with an increased inactivation of PSII, as indicated by the changes in kp.

The effect of temperature on the aggregation kinetics of partially bare gold nanoparticles

RSC Advances ◽  
2016 ◽  
Vol 6 (85) ◽  
pp. 82138-82149 ◽  
Author(s):  
Anushree Dutta ◽  
Anumita Paul ◽  
Arun Chattopadhyay
Keyword(s):  
Activation Energy ◽  
Gold Nanoparticles ◽  
Effect Of Temperature ◽  
Aggregation Kinetics ◽  
Temperature Dependent ◽  
Colloidal Aggregation ◽  
First Order ◽  
First Order Kinetics ◽  
Kinetics Of ◽  
Bare Gold

Temperature dependent aggregation reaction of partially bare gold nanoparticles showed a first order kinetics and prevalence of reaction limited colloidal aggregation with an activation energy equal to 36.2 ± 3.0 kJ mol−1.

The kinetics of polysulphone formation II. The formation of 1-butene polysulphone in the region of the ceiling temperature

1952 ◽  
Vol 212 (1109) ◽  
pp. 207-220 ◽  
Keyword(s):  
Monomer Concentration ◽  
Effect Of Temperature ◽  
Kcal Mole ◽  
Temperature Dependent ◽  
Chain Polymer ◽  
Free Energy Of Formation ◽  
Ceiling Temperature ◽  
Liquid Sulphur ◽  
State 1 ◽  
Kinetics Of

The effect of temperature on the rate of formation of 1-butene polysulphone from mixtures of liquid sulphur dioxide and 1-butene has been investigated dilatometrically. Three methods of initiation were used: photochemical, silver nitrate and benzoyl peroxide, and the temperature range covered was 0 to 70° C. For appreciable rates of reaction, the photochemical rate may be expressed in the form: rate = k 1 [ B ] [ S ] — k 2 , where [ B ] [ S ] denotes the monomer concentration product and k 1 and k 2 are temperature-dependent constants. For each reaction mixture there is a critical temperature defined as the ceiling temperature T c above which the reaction rate and molecular weight of polymer formed are very small. This temperature is independent of the method and rate of initiation. Previous explanations of the ceiling temperature phenomenon are shown to be unsound. The present results may be interpreted on the assumption that the reverse of the propaga­tion reaction, here designated the depropagation reaction, becomes important as the ceiling temperature is approached. The kinetic data permit the evaluation of both the heat and entropy of polymerization, and for the reaction (l - C 4 H 8 + SO 2 ) liq. mixt → 1/ n (C 4 H 8 SO 2 ) n (solution in monomer mixture), — Δ H = 20.7 ± 1.4 kcal mole -1 , — Δ S ° = 68.2 cal mole -1 ° K -1 (standard state 1 mole l. -1 each reactant). The heat change determined by adiabatic calorimetry is 22.0 ± 0.7 kcal mole -1 . In principle, all polymerization systems should exhibit the ceiling temperature effect under suitable conditions. Possible systems for investigation are suggested. The ceiling temperature is the temperature at which the free energy of formation of long-chain polymer is zero. Above the ceiling temperature the polymer is thermodynamically unstable. Depolymerization experiments on I-butene polysulphone indicate that below 130° C the degradation is random in character, whether effected by light or by heat.

Photosynthetic responses of Coffea arabica leaves to a short-term high light exposure in relation to N availability

1997 ◽  
Vol 101 (1) ◽  
pp. 229-239 ◽  
Author(s):  
Jose C. Ramalho ◽  
Thos L. Pons ◽  
Henri W. Groeneveld ◽  
M. Antonieta Nunes
Keyword(s):  
Coffea Arabica ◽  
Light Exposure ◽  
High Light ◽  
N Availability ◽  
Short Term ◽  
Photosynthetic Responses

Predicting cold-water bleaching in corals: role of temperature, and potential integration of light exposure

2020 ◽  
Vol 642 ◽  
pp. 133-146
Author(s):  
PC González-Espinosa ◽  
SD Donner
Keyword(s):  
Coral Bleaching ◽  
Cold Water ◽  
Light Exposure ◽  
Light Attenuation ◽  
Florida Keys ◽  
Cold Temperature ◽  
Warm Water ◽  
Coral Tissue ◽  
Effect Of Temperature ◽  
Type I

Warm-water growth and survival of corals are constrained by a set of environmental conditions such as temperature, light, nutrient levels and salinity. Water temperatures of 1 to 2°C above the usual summer maximum can trigger a phenomenon known as coral bleaching, whereby disruption of the symbiosis between coral and dinoflagellate micro-algae, living within the coral tissue, reveals the white skeleton of coral. Anomalously cold water can also lead to coral bleaching but has been the subject of limited research. Although cold-water bleaching events are less common, they can produce similar impacts on coral reefs as warm-water events. In this study, we explored the effect of temperature and light on the likelihood of cold-water coral bleaching from 1998-2017 using available bleaching observations from the Eastern Tropical Pacific and the Florida Keys. Using satellite-derived sea surface temperature, photosynthetically available radiation and light attenuation data, cold temperature and light exposure metrics were developed and then tested against the bleaching observations using logistic regression. The results show that cold-water bleaching can be best predicted with an accumulated cold-temperature metric, i.e. ‘degree cooling weeks’, analogous to the heat stress metric ‘degree heating weeks’, with high accuracy (90%) and fewer Type I and Type II errors in comparison with other models. Although light, when also considered, improved prediction accuracy, we found that the most reliable framework for cold-water bleaching prediction may be based solely on cold-temperature exposure.

Temperature Effect on the Two-Dimensional Phase Transition Kinetics of Adenine Adsorbed at the Hg Electrode/Aqueous Solution Interface

2003 ◽  
Vol 68 (8) ◽  
pp. 1407-1419 ◽  
Author(s):  
Claudio Fontanesi ◽  
Roberto Andreoli ◽  
Luca Benedetti ◽  
Roberto Giovanardi ◽  
Paolo Ferrarini
Keyword(s):  
Phase Transition ◽  
Aqueous Solution ◽  
Phase Change ◽  
Temperature Effect ◽  
Transition Rate ◽  
Effect Of Temperature ◽  
Two Dimensional ◽  
Solution Interface ◽  
Phase Transition Kinetics ◽  
Kinetics Of

The kinetics of the liquid-like → solid-like 2D phase transition of adenine adsorbed at the Hg/aqueous solution interface is studied. Attention is focused on the effect of temperature on the rate of phase change; an increase in temperature is found to cause a decrease of transition rate.

Temperature Dependent Kinetics of the OH/HO2/O3Chain Reaction by Time-Resolved IR Laser Absorption Spectroscopy

2000 ◽  
Vol 104 (17) ◽  
pp. 3964-3973 ◽  
Author(s):  
Sergey A. Nizkorodov ◽  
Warren W. Harper ◽  
Bradley W. Blackmon ◽  
David J. Nesbitt
Keyword(s):  
Absorption Spectroscopy ◽  
Laser Absorption Spectroscopy ◽  
Temperature Dependent ◽  
Time Resolved ◽  
Laser Absorption ◽  
Ir Laser ◽  
Kinetics Of
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