scholarly journals Studies on the red absorption band of chlorophyll a in vivo

1965 ◽  
Vol 102 (2) ◽  
pp. 324-332 ◽  
Author(s):  
J.B. Thomas ◽  
J.W. Kleinen Hammans ◽  
W.J. Arnolds
Keyword(s):  
Absorption Band ◽  
Chlorophyll A

In Vivo Fluorescence of Chlorophyll A: Estimation of Phytoplankton Biomass and Activity in Římov Reservoir (Czech Republic)

1993 ◽  
Vol 28 (6) ◽  
pp. 29-33 ◽  
Author(s):  
V. Vyhnálek ◽  
Z. Fišar ◽  
A. Fišarová ◽  
J. Komárková
Keyword(s):  
Czech Republic ◽  
Chlorophyll Fluorescence ◽  
Primary Production ◽  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
In Vivo Fluorescence ◽  
Fluorescence Of Chlorophyll A ◽  
Římov Reservoir ◽  
Natural Phytoplankton

The in vivo fluorescence of chlorophyll a was measured in samples of natural phytoplankton taken from the Římov Reservoir (Czech Republic) during the years 1987 and 1988. The fluorescence intensities of samples either with or without addition of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron, DCMU) were found reliable for calculating the concentration of chlorophyll a during periods when cyanobacteria were not abundant. The correction for background non-chlorophyll fluorescence appeared to be essential. No distinct correlation between a DCMU-induced increase of the fluorescence and primary production of phytoplankton was found.

The Deep Chlorophyll Maximum: Comparing Vertical Profiles of Chlorophyll a

1982 ◽  
Vol 39 (5) ◽  
pp. 791-803 ◽  
Author(s):  
John J. Cullen
Keyword(s):  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Physiological Adaptation ◽  
Organic Carbon Content ◽  
Deep Chlorophyll Maximum ◽  
Vertical Profiles ◽  
In Vivo Fluorescence ◽  
Chlorophyll Maximum ◽  
Vertical Distributions

The relationship between chlorophyll a and phytoplankton biomass (organic carbon content) is highly variable as is the yield of in vivo fluorescence per unit chlorophyll. Thus, vertical profiles of chlorophyll or in vivo fluorescence must be interpreted with caution if their ecological significance is to be established. Although the variability of carbon-to-chlorophyll ratios and fluorescence yield is large, much of it can be anticipated, corrected for, and usefully interpreted. Vertical profiles from different regions of the sea are presented; each has a deep chlorophyll maximum, but the probable mechanisms of their formation and maintenance differ widely. Most vertical distributions of chlorophyll can be explained by the interaction between hydrography and growth, behavior, or physiological adaptation of phytoplankton with no special consideration of grazing by herbivores, even though vertical distributions of epizooplankton are not uniform. The interaction between vertical profiles of zooplankton and chlorophyll will be better understood when the relationships between chlorophyll and phytoplankton biomass in those profiles is determined.Key words: chlorophyll a, fluorescence, phytoplankton, vertical structure

scholarly journals SENSITIVITY TO ENVIRONMENTAL STRESS OF PRATA,JAPIRA AND VITÓRIA BANANA CULTIVARS PROVEN BY CHLOROPHYLL a FLUORESCENCE

2017 ◽  
Vol 39 (2) ◽  
Author(s):  
PRISCILA NOBRES DOS SANTOS ◽  
DIOLINA MOURA SILVA ◽  
CAMILLA ZANOTTI GALLON ◽  
JOSÉ AIRES VENTURA
Keyword(s):  
Environmental Stress ◽  
Chlorophyll A ◽  
Chlorophyll A Fluorescence ◽  
Physiological Responses ◽  
Fluorescence Emission ◽  
Conservation Of Energy ◽  
Post Harvest ◽  
Mda Content ◽  
Two Stages

ABSTRACT This study aimed to evaluate the physiological responses to environmental stress during pre- and post-harvest of the following banana cultivars: Prata (AAB), Japira (AAAB) and Vitoria (AAAB). Analyses were carried out on young plants at vegetative stage (daughter-plant) and adult plants at reproductive stage (motherplant). The experimental design was completely randomized. In the in vivo pre-harvest analysis were used seven replications, in a factorial scheme (3x2x2), three cultivars and two stages (vegetative and reproductive) and two collection periods (March and June). For the analysis of post-harvest quality were used five replications in a factorial design (3x2x5), corresponding to three cultivars, two development stages and five periods of post-harvest analysis, carried out every two days from stage 4 of fruit ripening. The chlorophyll a fluorescence emission kinetics showed low photochemical performance of the three cultivars in June, a period characterized by lower temperatures and water deficit. Prata was the cultivar with the lowest tolerance to abiotic physiological behavior changes, which also reflected in fruit quality, because there was a change in physical and physicochemical parameters. Japira and Vitoria cultivars showed similar physiological responses in the pre- and post-harvest periods, according to their phylogenetic proximity. The total performance index, i.e., the conservation of energy absorbed by PSII up to the reduction of the final PSI acceptors (PItotal) and the di-malonic aldehyde (MDA) content were significantly higher in Japira and Vitoria cultivars compared to Prata cultivar in the reproductive phase. There was no significant change in the potential quantum efficiency of PSII (FV / FM = jP0) among the three cultivars. It was concluded that Japira and Vitoria cultivars showed greater plasticity to tolerate or even adapt to abiotic variations keeping higher fruit yield. PItotal is the most sensitive parameter during the banana life cycle and important tool for distinguishing different cultivars yields.

Der einflub von cycloheximid und chloramphenicol auf die biosynthese der photosynthese-pigmente in cyanophora paradoxa korsch. III. chlorophyll a und phycochromoproteide / The influence of cycloheximide and chloramphenicol on the biosynthesis of the photosvnthetic pigments in cyanophora paradoxa. III. chlorophyll a and phycochromoproteids

1983 ◽  
Vol 38 (11-12) ◽  
pp. 990-995 ◽  
Author(s):  
Margarete Neu-Müller ◽  
Hainfried E. A. Schenk
Keyword(s):  
Chlorophyll A ◽  
Cyanophora Paradoxa ◽  
Inhibition Effect ◽  
Vis Spectroscopy ◽  
Chl Biosynthesis ◽  
Better Than

The inhibition effects of CHI and CA on the biosynthesis of the tetrapyrrolpigments were measured with two methods (in vivo VIS-spectroscopy, for chlorophyll (Chi) and the phycochromoproteids, 14C incorporation only for Chi). In the case of the Chl-biosynthesis both methods show the same results: a) In vivo VIS-spectroscopy demonstrates that the inhibition effect of CA manifests faster than that of CHI, b) during the 14C incorporation into Chi chloramphenicol (CA) inhibits more than cyclohexim ide (CHI) in contrary to the behaviour of chloroplasts. It seems that the CHI caused decrease of 14C incorporation into Chi can be ascribed to the decreased photosynthesis. The influence o f the antibiotics of the phycochrom oproteids is similar to that observed for chlorophyll. It is remarkable that under the influence of CHI the phycochromoproteid biosynthesis is significantly better than under CA influence, although CHI damages the consortium more than CA. That can be interpreted, as for chlorophyll, with a more endocytobiont coded phycochrom oproteid synthesis

Reduction of the Formyl Group of Zinc Pheophorbide b in vitro and in vivo: a Model for the Chlorophyll b to a Transformation

1996 ◽  
Vol 51 (3-4) ◽  
pp. 185-194 ◽  
Author(s):  
Verena Scheumann ◽  
Michael Helfrich ◽  
Siegrid Schoch ◽  
Wolfhart Rüdiger
Keyword(s):  
Nmr Spectroscopy ◽  
Chlorophyll A ◽  
Chemical Reduction ◽  
Chlorophyll B ◽  
Formyl Group ◽  
Pheophorbide A ◽  
Pheophytin A ◽  
H Nmr

Abstract The chemical reduction of the formyl group of pheophorbide b with sodium cyanoborohy­ dride in methanol leads to 71-methoxy-and 71-hydroxy-pheophorbide a. The same reaction with zinc pheophorbide b yields in addition zinc pheophorbide a. This was characterized by mass and 1H -NMR spectroscopy. Infiltration of zinc pheophorbides a and b and of zinc 71-hydroxy-pheophorbide a into etiolated oat leaves yielded phytylated products. The best yield in the esterification was obtained with 71-hydroxy-pheophorbide a. Analysis of the products revealed the formation of zinc pheophytin a from all infiltrated compounds. The significance for the transformation of chlorophyll b into chlorophyll a is discussed.

Structural effects on epimerization of bacteriochlorophyll a and chlorophyll a revealed using 3-acetyl chlorophyll a

2020 ◽  
Vol 24 (04) ◽  
pp. 499-504 ◽  
Author(s):  
Yoshitaka Saga ◽  
Shiori Nakagawa
Keyword(s):  
Physicochemical Properties ◽  
Chlorophyll A ◽  
Photosynthetic Reaction Center ◽  
Molecular Structures ◽  
Structural Factors ◽  
Structural Effects ◽  
Photosynthetic Organisms ◽  
Acetyl Group ◽  
Kinetics Of

Chlorophyll (Chl) and bacteriochlorophyll (BChl) pigments, which are crucial cyclic tetrapyrroles in photosynthesis, generally have a chiral center in their exo-cyclic five-membered E-ring. Although [Formula: see text]-epimers (primed-type) of (B)Chl pigments are rarely present in photosynthetic organisms, they play key roles in photosynthetic reaction center complexes. The epimerization mechanism of (B)Chl pigments in vivo has not been unraveled. The structural effects on the physicochemical properties of (B)Chl epimerization reactions provide useful information to tackle this question. We analyzed epimerization of three pigments, BChl [Formula: see text], Chl [Formula: see text], and 3-acetyl Chl [Formula: see text], to elucidate the structural factors that are responsible for epimerization reactions. We compared the epimerization kinetics of the three pigments and concluded that the bacteriochlorin skeleton (7,8,17,18-tetrahydroporphyrin) significantly retarded the epimerization kinetics. Thus, BChl [Formula: see text] exhibited slower epimerization kinetics than Chl [Formula: see text] in spite of the presence of the electron-withdrawing 3-acetyl group that accelerates epimerization. In contrast to the large structural effects of (B)Chl molecules on epimerization kinetics, the thermodynamic properties at equilibrium in the epimerization of the three pigments were barely influenced by their molecular structures. This study also demonstrates that a semi-synthetic pigment, 3-acetyl Chl [Formula: see text], is appropriate for comparative analyses of the structural effects of BChl [Formula: see text] and Chl [Formula: see text] on their physicochemical properties.

scholarly journals Light-Induced Changes in the Fluorescence Yield of Chlorophyll a In Vivo

1968 ◽  
Vol 8 (11) ◽  
pp. 1316-1328 ◽  
Author(s):  
George Papageorgiou ◽  
Govindjee
Keyword(s):  
Chlorophyll A ◽  
Fluorescence Yield ◽  
Induced Changes
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