scholarly journals An Investigation of the Sustained Component of Nonphotochemical Quenching of Chlorophyll Fluorescence in Isolated Chloroplasts and Leaves of Spinach

1995 ◽  
Vol 108 (2) ◽  
pp. 721-726 ◽  
Author(s):  
A. V. Ruban ◽  
P. Horton
Keyword(s):  
Chlorophyll Fluorescence ◽  
Nonphotochemical Quenching ◽  
Isolated Chloroplasts

scholarly journals A minimal mathematical model of nonphotochemical quenching of chlorophyll fluorescence

Biosystems ◽  
2011 ◽  
Vol 103 (2) ◽  
pp. 196-204 ◽  
Author(s):  
Oliver Ebenhöh ◽  
Torsten Houwaart ◽  
Heiko Lokstein ◽  
Stephanie Schlede ◽  
Katrin Tirok
Keyword(s):  
Mathematical Model ◽  
Chlorophyll Fluorescence ◽  
Nonphotochemical Quenching

scholarly journals Leaf Chlorophyll Fluorescence Parameters and Huanglongbing

2009 ◽  
Vol 134 (2) ◽  
pp. 194-201 ◽  
Author(s):  
Madhulika Sagaram ◽  
Jacqueline K. Burns
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photosynthetic Efficiency ◽  
Heat Dissipation ◽  
Sweet Orange ◽  
Severe Symptom ◽  
Starch Content ◽  
Fluorescence Analysis ◽  
Nonphotochemical Quenching ◽  
Recent Infection ◽  
Chlorophyll Fluorescence Parameters

Chlorophyll fluorescence and photochemical and nonphotochemical quenching parameters were measured in 20 genotypes of Citrus spp. or relatives grown in the greenhouse and commercial ‘Valencia’ sweet orange (Citrus sinensis) trees at two Florida locations. The purpose was to determine the utility of measurements for early huanglongbing [HLB (Candidatus Liberibacter asiaticus)] detection in asymptomatic trees and to examine the leaf response to HLB infection. Polymerase chain reaction (PCR)-negative healthy and PCR-positive symptomatic, asymptomatic, and distant asymptomatic leaves were used for fluorescence analysis using a portable chlorophyll fluorometer. Greenhouse-grown genotypes were separated into mild, moderate, and severe symptom groups based on leaf mottling, color, and size. In general, mild symptom genotypes were characterized by increased photosystem II (PSII) excitation pressure and unregulated heat dissipation and decreased regulated heat dissipation, whereas moderate and severe symptom genotypes increased loss of photosynthetic efficiency and increased unregulated and regulated heat dissipation. Distant asymptomatic leaves could be distinguished from healthy ones in moderate and severe symptom genotypes by increased total and regulated heat dissipation measurements. In the field, overall photosynthetic efficiency and total regulated heat dissipation measurements could distinguish between healthy and asymptomatic ‘Valencia’ sweet orange leaves at the location with slow or more recent infection, but not at the location where infection appeared to progress faster or was of longer duration. Starch content followed a similar pattern. The results indicate that no single measurement uniquely described the relationship between HLB and the host in asymptomatic and healthy leaves, but accuracy of field-based detection could be strengthened by a combination of total nonphotochemical quenching, overall photosynthetic efficiency, starch content, and PCR analyses. Chlorophyll fluorescence and quenching measurements suggest a PSII-based explanation for, and temperature dependency of, leaf symptom development.

Effects of aging on chlorophyll fluorescence and photosystem II electron transport in isolated chloroplasts

1975 ◽  
Vol 53 (23) ◽  
pp. 2842-2845 ◽  
Author(s):  
M. Fragata
Keyword(s):  
Fatty Acids ◽  
Chlorophyll Fluorescence ◽  
Photosystem Ii ◽  
Conformational Changes ◽  
Photochemical Activity ◽  
Photosynthetic Membrane ◽  
Fluorescence Characteristics ◽  
Protein Molecules ◽  
Effects Of Aging ◽  
Isolated Chloroplasts

The correlation between emission of energy and photochemical activity in isolated chloroplasts during aging was investigated. It was shown that aging hinders the intensity of chlorophyll-a fluorescence with a concomitant decrease of the photosystem II activity. In view of the parallelism between the action of exogenous fatty acids, especially C18-unsaturated acids, and the effects of aging, it is suggested that the thylakoid transformation during aging could result partly from conformational changes of the membrane polypeptides due to the presence of free fatty acids in the neighborhood of the protein molecules. It is possible that such a mechanism of fatty acid action may alter the fluorescence characteristics of chlorophyll as well as the tunneling of electrons in the photosynthetic membrane.

Light-Dependent Interactions of Phenazine Methosulfate with 3-(3,4-Dichlorophenyl)-1,1-dimethylurea-Poisoned Chloroplasts

1976 ◽  
Vol 31 (11-12) ◽  
pp. 722-729 ◽  
Author(s):  
Bernd Schmidt ◽  
Hans Rurainski
Keyword(s):  
Chlorophyll Fluorescence ◽  
Transient Absorption ◽  
Energy State ◽  
Spectral Characteristics ◽  
High Energy ◽  
Phenazine Methosulfate ◽  
Experimental Conditions ◽  
Absorption Change ◽  
High Energy State ◽  
Isolated Chloroplasts

Abstract The chlorophyll fluorescence of isolated chloroplasts in the presence of phenazine methosulfate (PMS) and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) can be quenched in a light-dependent reaction. This phenomenan has been studied and the following observations were made: 1. Quenching occurs under non-phosphorylating conditions and is stimulated by Mg2+ ions. 2. Under the same conditions, a light-dependent, Mg2+ stimulated transient decrease of absorp­ tion at 388 nm is observed which shows the spectral characteristics of PMS. 3. PMS is reversibly bound to chloroplasts. Under the experimental conditions used, binding amounts to as much as 0.5 mol PMS/mol chlorophyll. 4. Some uncouplers of photophosphorylation such as carbonylcyanide-m-chlorophenylhydrazon (CCCP) and atebrin analog abolish quenching, transient absorption change and binding of PMS. Others, such as methylamine, ammonia, gramicidin and nigericin do not. It is suggested that fluorescence quenching, transient absorption change and binding of PMS are causally related. The concept, postulated by others, that a high-energy state of the chloroplast membrane is involved in the fluorescence lowering is questioned.

scholarly journals Nonphotochemical Quenching of Chlorophyll Fluorescence inChlamydomonas reinhardtii

Biochemistry ◽  
2006 ◽  
Vol 45 (5) ◽  
pp. 1490-1498 ◽  
Author(s):  
Giovanni Finazzi ◽  
Giles N. Johnson ◽  
Luca Dall'Osto ◽  
Francesca Zito ◽  
Giulia Bonente ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Nonphotochemical Quenching
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