scholarly journals Zeaxanthin and the Heat Dissipation of Excess Light Energy in Nerium oleander Exposed to a Combination of High Light and Water Stress

1988 ◽  
Vol 87 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Barbara Demmig ◽  
Klaus Winter ◽  
Almuth Krüger ◽  
Franz-Christian Czygan
Keyword(s):  
Water Stress ◽  
Heat Dissipation ◽  
High Light ◽  
Light Energy ◽  
Nerium Oleander ◽  
Excess Light

Different strategies of acclimation of photosynthesis, electron transport and antioxidative activity in leaves of two cotton species to water deficit

2016 ◽  
Vol 43 (5) ◽  
pp. 448 ◽  
Author(s):  
Xiao-Ping Yi ◽  
Ya-Li Zhang ◽  
He-Sheng Yao ◽  
Hong-Hai Luo ◽  
Ling Gou ◽  
...  
Keyword(s):  
Electron Transport ◽  
Water Deficit ◽  
Heat Dissipation ◽  
Photosynthetic Apparatus ◽  
Light Energy ◽  
Photochemical Quenching ◽  
Antioxidant Systems ◽  
Mehler Reaction ◽  
Cotton Species ◽  
Excess Light

To better understand the adaptation mechanisms of the photosynthetic apparatus of cotton plants to water deficit conditions, the influence of water deficit on photosynthesis, chlorophyll a fluorescence and the activities of antioxidant systems were determined simultaneously in Gossypium hirsutum L. cv. Xinluzao 45 (upland cotton) and Gossypium barbadense L. cv. Xinhai 21 (pima cotton). Water deficit decreased photosynthesis in both cotton species, but did not decrease chlorophyll content or induce any sustained photoinhibition in either cotton species. Water deficit increased ETR/4 − AG, where ETR/4 estimates the linear photosynthetic electron flux and AG is the gross rate of carbon assimilation. The increase in ETR/4 − AG, which represents an increase in photorespiration and alternative electron fluxes, was particularly pronounced in Xinluzao 45. In Xinluzao 45, water deficit increased the activities of antioxidative enzymes, as well as the contents of reactive oxygen species (ROS), which are related to the Mehler reaction. In contrast, moderate water deficit particularly increased non-photochemical quenching (NPQ) in Xinhai 21. Our results suggest that Xinluzao 45 relied on enhanced electron transport such as photorespiration and the Mehler reaction to dissipate excess light energy under mild and moderate water deficit. Xinhai 21 used enhanced photorespiration for light energy utilisation under mild water deficit but, when subjected to moderate water deficit, possessed a high capacity for dissipating excess light energy via heat dissipation.

scholarly journals Atmospheric Nitrogen Dioxide Improves Photosynthesis in Mulberry Leaves via Effective Utilization of Excess Absorbed Light Energy

Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 312 ◽  
Author(s):  
Yue Wang ◽  
Weiwei Jin ◽  
Yanhui Che ◽  
Dan Huang ◽  
Jiechen Wang ◽  
...  
Keyword(s):  
Nitrogen Dioxide ◽  
Nitrogen Metabolism ◽  
Heat Dissipation ◽  
Photosynthetic Apparatus ◽  
Air Pollutant ◽  
Light Energy ◽  
Plant Leaves ◽  
Plant Nitrogen ◽  
Mulberry Leaves ◽  
Excess Light

Nitrogen dioxide (NO2) is recognized as a toxic gaseous air pollutant. However, atmospheric NO2 can be absorbed by plant leaves and subsequently participate in plant nitrogen metabolism. The metabolism of atmospheric NO2 utilizes and consumes the light energy that leaves absorb. As such, it remains unclear whether the consumption of photosynthetic energy through nitrogen metabolism can decrease the photosynthetic capacity of plant leaves or not. In this study, we fumigated mulberry (Morus alba L.) plants with 4 μL·L−1 NO2 and analyzed the distribution of light energy absorbed by plants in NO2 metabolism using gas exchange and chlorophyll a fluorescence technology, as well as biochemical methods. NO2 fumigation enhanced the nitrogen metabolism of mulberry leaves, improved the photorespiration rate, and consumed excess light energy to protect the photosynthetic apparatus. Additionally, the excess light energy absorbed by the photosystem II reaction center in leaves of mulberry was dissipated in the form of heat dissipation. Thus, light energy was absorbed more efficiently in photosynthetic carbon assimilation in mulberry plants fumigated with 4 μL·L−1 NO2, which in turn increased the photosynthetic efficiency of mulberry leaves.

THE INFLUENCE OF THE RATIO OF INCANDESCENT TO FLUORESCENT LIGHT ON THE FLOWERING RESPONSE OF MARQUIS WHEAT GROWN UNDER CONTROLLED CONDITIONS

1961 ◽  
Vol 41 (2) ◽  
pp. 418-427 ◽  
Author(s):  
D. J. C. Friend ◽  
V. A. Helson ◽  
J. E. Fisher
Keyword(s):  
Stem Elongation ◽  
High Light ◽  
Light Energy ◽  
Fluorescent Light ◽  
Floral Initiation ◽  
Incandescent Light ◽  
Flowering Response ◽  
Controlled Conditions ◽  
Floral Differentiation ◽  
Plant Level

When Marquis wheat is grown under artificial conditions, the main light energy (lamp watts) supplied by fluorescent light should be supplemented by at least 35 per cent of incandescent light in order to have a photoperiodic effect close to the maximal. Increasing the percentage up to 100 per cent resulted in slightly earlier flowering. This effect of incandescent light was caused, not by earlier floral initiation, but by an increase in the rate of stem elongation and a hastening of the later stages of floral differentiation. This action of incandescent light could not be replaced by substituting pink fluorescent for one-third of the white fluorescent lights.To obtain a photoperiodic effect equal to that of high light energy from combined fluorescent and incandescent bulbs, it is recommended that the daylength be extended by sufficient incandescent light to give an intensity of at least 50 ft.-c. at plant level.

Responses of the photosynthetic electron transport system to excess light energy caused by water deficit in wild watermelon

2011 ◽  
Vol 142 (3) ◽  
pp. 247-264 ◽  
Author(s):  
Satoko Sanda ◽  
Kazuo Yoshida ◽  
Masayoshi Kuwano ◽  
Tadayuki Kawamura ◽  
Yuri Nakajima Munekage ◽  
...  
Keyword(s):  
Electron Transport ◽  
Water Deficit ◽  
Transport System ◽  
Photosynthetic Electron Transport ◽  
Light Energy ◽  
Electron Transport System ◽  
Excess Light

High Yield Achieved by Early-Maturing Rapeseed with High Light Energy and Temperature Production Efficiencies under Ideal Planting Density

Crop Science ◽  
2019 ◽  
Vol 59 (1) ◽  
pp. 351-362 ◽  
Author(s):  
Zhenghua Xu ◽  
Tao Luo ◽  
Na Rao ◽  
Liang Yang ◽  
Jiahuan Liu ◽  
...  
Keyword(s):  
High Light ◽  
Light Energy ◽  
Planting Density ◽  
High Yield ◽  
Early Maturing ◽  
Production Efficiencies

scholarly journals Radiative energy budget reveals high photosynthetic efficiency in symbiont-bearing corals

2014 ◽  
Vol 11 (93) ◽  
pp. 20130997 ◽  
Author(s):  
Kasper Elgetti Brodersen ◽  
Mads Lichtenberg ◽  
Peter J. Ralph ◽  
Michael Kühl ◽  
Daniel Wangpraseurt
Keyword(s):  
Energy Budget ◽  
Photosynthetic Efficiency ◽  
Light Field ◽  
Heat Dissipation ◽  
Spectral Composition ◽  
Light Energy ◽  
Low Energy ◽  
Radiative Energy ◽  
Gross Photosynthesis ◽  
Light Utilization

The light field on coral reefs varies in intensity and spectral composition, and is the key regulating factor for phototrophic reef organisms, for example scleractinian corals harbouring microalgal symbionts. However, the actual efficiency of light utilization in corals and the mechanisms affecting the radiative energy budget of corals are underexplored. We present the first balanced light energy budget for a symbiont-bearing coral based on a fine-scale study of the microenvironmental photobiology of the massive coral Montastrea curta . The majority (more than 96%) of the absorbed light energy was dissipated as heat, whereas the proportion of the absorbed light energy used in photosynthesis was approximately 4.0% under an irradiance of 640 µmol photons m −2 s −1 . With increasing irradiance, the proportion of heat dissipation increased at the expense of photosynthesis. Despite such low energy efficiency, we found a high photosynthetic efficiency of the microalgal symbionts showing high gross photosynthesis rates and quantum efficiencies (QEs) of approximately 0.1 O 2 photon −1 approaching theoretical limits under moderate irradiance levels. Corals thus appear as highly efficient light collectors with optical properties enabling light distribution over the corallite/tissue microstructural canopy that enables a high photosynthetic QE of their photosynthetic microalgae in hospite .

scholarly journals Use of Crop Water Stress Index to Schedule Irrigation of Freeway Landscape Plants

HortScience ◽  
1990 ◽  
Vol 25 (3) ◽  
pp. 302-305 ◽  
Author(s):  
Alexander X. Niemiera ◽  
Monika Goy
Keyword(s):  
Water Stress ◽  
Nerium Oleander ◽  
Stress Index ◽  
Crop Water ◽  
Crop Water Stress Index ◽  
Water Stress Index ◽  
Landscape Plants ◽  
Cercidium Floridum ◽  
Eucalyptus Microtheca ◽  
Crop Water Stress

A study was conducted to determinethe feasibility of using crop water stress index (CWSI) to schedule irrigation of eight species of freeway landscape plants, Acacia redolens B.R. Maslin, Acacia salicina Lindl., Caesalpinia pulcherrima Sw., Cassia nemophila A. Cunn. ex Vogel, Cercidium floridum Benth., Eucalyptus microtheca F.J. Muell., Nerium oleander L., and Prosopis chilensis Mol. Nerium oleander and C. pulcherrima were suited to the use of the CWSI, tolerated repeated exposures to CWSI values of 0.6, and remained aesthetically acceptable. Irrigation of N. oleander via the CWSI resulted in a 19% reduction in water use, compared to the conventional method. CWSI data of other species were too variable, and, thus, irrigation could not be scheduled by CWSI values. Variability was attributed, in part, to lack of a dense canopy, which is necessary to fill the view of the infrared thermometer.

scholarly journals The influence of temperature, light energy and photoperiod on flowering of Brodiaea laxa Wats.

1969 ◽  
Vol 17 (3) ◽  
pp. 176-182
Author(s):  
E.J. Fortanier
Keyword(s):  
Flower Development ◽  
High Light ◽  
Light Energy ◽  
Light Conditions ◽  
Influence Of Temperature ◽  
Flower Production ◽  
Short Day ◽  
Light Intensities ◽  
Light Requirements

Temperature and light requirements for a satisfactory forcing of Brodiaea laxa 'Koningin Fabiola' were studied. Corms were planted under different temperature and light conditions in a phytotron and in different photoperiods in the open. Long days accelerated flower development and the termination of growth and enhanced corm formation. Considering both earliness and number of flowers, the most acceptable results with regard to flower production were obtained at 18 degrees C. in short photoperiods. Forcing at higher temperatures and in longer photoperiods resulted in a reduction in the number of flowers because of bud blasting. This also occurred when the natural short day was extended by high light intensities. Forced and retarded corms reacted similarly but the latter flowered sooner and more satisfactorily. Flowering was preceded under all conditions by corm formation and in longer photoperiods even by senescence of the leaves. Year-round production of flowers is possible if 25 cal./sq.cm./day of light energy or more are available.- Agric. Univ., Wageningen. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals UV-B photoreceptor-mediated protection of the photosynthetic machinery inChlamydomonas reinhardtii

2016 ◽  
Vol 113 (51) ◽  
pp. 14864-14869 ◽  
Author(s):  
Guillaume Allorent ◽  
Linnka Lefebvre-Legendre ◽  
Richard Chappuis ◽  
Marcel Kuntz ◽  
Thuy B. Truong ◽  
...  
Keyword(s):  
Photosynthetic Activity ◽  
Light Harvesting ◽  
Nonphotochemical Quenching ◽  
High Light ◽  
Light Energy ◽  
Light Harvesting Complex ◽  
Subsequent Exposure ◽  
Photosynthetic Machinery ◽  
Life On Earth ◽  
Energy Dependent

Life on earth is dependent on the photosynthetic conversion of light energy into chemical energy. However, absorption of excess sunlight can damage the photosynthetic machinery and limit photosynthetic activity, thereby affecting growth and productivity. Photosynthetic light harvesting can be down-regulated by nonphotochemical quenching (NPQ). A major component of NPQ is qE (energy-dependent nonphotochemical quenching), which allows dissipation of light energy as heat. Photodamage peaks in the UV-B part of the spectrum, but whether and how UV-B induces qE are unknown. Plants are responsive to UV-B via the UVR8 photoreceptor. Here, we report in the green algaChlamydomonas reinhardtiithat UVR8 induces accumulation of specific members of the light-harvesting complex (LHC) superfamily that contribute to qE, in particular LHC Stress-Related 1 (LHCSR1) and Photosystem II Subunit S (PSBS). The capacity for qE is strongly induced by UV-B, although the patterns of qE-related proteins accumulating in response to UV-B or to high light are clearly different. The competence for qE induced by acclimation to UV-B markedly contributes to photoprotection upon subsequent exposure to high light. Our study reveals an anterograde link between photoreceptor-mediated signaling in the nucleocytosolic compartment and the photoprotective regulation of photosynthetic activity in the chloroplast.

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