Journal ArticleDOI
Interaction of light quality and benzimidazole on pigment contents and on photochemical activity of chloroplasts isolated from detached senescing wheat (Triticum aestivum) leaves
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TLDR
There was no effect of light and benzimidazole in retarding the loss in photochemical activity, although the same preserved the chlorophyll contents as well as characteristics of the chloroplast absorption spectrum.Abstract:
The possibilities of an interaction between light and the growth regulator benzimidazole in retarding senescence-induced changes in activity of chloroplasts isolated from detached wheat (Triticum aestivum L. cv. Kalyansona) leaves have been investigated. The effect of benzimidazole on the rate of degradation of chlorophylls in light depended on the quality of light used. Far-red irradiation given to detached leaves in the presence of benzimidazole retarded the pigment loss more significantly than did white or red light of similar intensity. Senescence-induced loss in chloroplast photochemical activity was higher than the loss of chlorophylls. Loss of photosystem I activity was greater than photosystem II activity. Benzimidazole maintained the gramicidin-mediated enhancement in whole chain electron transport uniformly throughout the incubation period irrespective of the light quality. There was no effect of light and benzimidazole in retarding the loss in photochemical activity, although the same preserved the chlorophyll contents as well as characteristics of the chloroplast absorption spectrum.read more
Citations
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Journal ArticleDOI
Analysis of thylakoid membrane protein and photosynthesis- related key enzymes in super high-yield hybrid rice LYPJ grown in field condition during senescence stage
Yuwen Wang,Jing Yu,Xiaohan Jiang,Lingang Sun,Kang Li,Ping-Yang Wang,Min Wu,Min Wu,Guoxiang Chen,Chuangen Lv +9 more
TL;DR: A proteomic analysis combining photosynthesis-related key enzymes measurement and mRNA level analysis was used to investigate the variations of proteins involved in the photosynthetic apparatus in flag leaves of high-yield rice LYPJ during senescence under field conditions, showing that Ca2+-ATPase was more stable duringsenescence of flag leaves in rice.
Book ChapterDOI
Ultrastructural modifications and biochemical changes during senescence of chloroplasts
U.C. Blswal,Basanti Biswal +1 more
TL;DR: This chapter discusses the recent findings of chloroplast degradation and provides an overview of organelle senescence, and discusses a general pattern of temporal changes in the fine structure of different cellular organelles, including chloroplasts.
Journal ArticleDOI
Ultrastructural and biochemical changes in chloroplasts during Brassica napus senescence
TL;DR: High levels of PSII activity were associated with large numbers of stacked grana; whereas loss of activity during week 2 was accompanied by reduced compactness of grana and the aggregation and enlargement of plastoglobuli.
Journal ArticleDOI
Possible mechanisms of light-induced chlorophyll degradation in senescing leaves of Hydrilla verticillata
R. K. Kar,M. A. Choudhuri +1 more
TL;DR: Retardation of light-induced chlorophyll loss occurred during senescence of Hydrilla leaves when light was given in different photoperiods in a 24-h daily cycle for 6 days instead of as continuous irradiance.
Journal ArticleDOI
H2O2 Metabolism During Senescence of Two Submerged Angiosperms Hydrilla and Ottelia: Changes in Enzyme Activities in Light and Darkness
Hasna Hena Begam,M.A. Choudhuri +1 more
TL;DR: In this paper, the role of H2O2 on senescence and photobleaching of chlorophyll was studied in Hydrilla verticillata (L.f.) Royle and Ottelia alismoides (L.) Pers. leaves, more markedly so in the light than in the dark.
References
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Copper enzymes in isolated chloroplasts. polyphenoloxidase in beta vulgaris
TL;DR: Evidence that a copper enzyme, polyphenoloxidase (otherwise known as tyrosinase or catecholase), is localized in the chloroplasts of spinach beet (chard), Beta vu?garis is presented.
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Effect of blue‐green light on photosynthetic pigments and chloroplast structure in unicellular marine algae from six classes1
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Journal ArticleDOI
Photocontrol of leaf senescence
U. C. Biswal,Basanti Biswal +1 more
TL;DR: Biswal et al. as discussed by the authors investigated the role of light in controlling the last phase of leaf development and found that high light intensities not only accelerate chlorophyll breakdown, but also lead to ultrastructural modifications and loss in soluble carbohydrates.
Journal ArticleDOI
The nature of the photosynthate in natural phytoplankton populations in relation to light quality
D. G. Wallen,G. H. Geen +1 more
TL;DR: The relative concentrations of a variety of organic compounds in phytoplankton from different depths of the photic zone of Saanich Inlet and Indian Arm, British Columbia, Canada, were determined and indicated that these observed changes were in response to light quality rather than intensity.
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