The mechanisms of fatty-acid inhibition of electron transport in chloroplasts

Венедиктов, П.С.; Krivoshejeva, Alla A.

doi:10.1007/bf00392076

Cited by 19 publications

(13 citation statements)

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“…Fatty acids of this form are known to be more toxic to aquatic organisms than uncharged forms (Procter 1957). This was further verified by Vedediktov and Krivoshejeva (1983) by studying the inhibitory effects of fatty acids on photosynthesis. Apparently, the pH of Liyu Lake enhances the toxicity of free fatty acids and, as a result, favors the dominance of B. braunii .…”

Section: Discussionmentioning

confidence: 73%

ALLELOCHEMICALS OF BOTRYOCOCCUS BRAUNII (CHLOROPHYCEAE)¹

Chiang

Huang

2004

Journal of Phycology

117

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The alga Botryococcus braunii Kützing (Chlorophyceae) present in Liyu Lake (Huanlien County, Taiwan) has toxic effects on a variety of aquatic organisms. Blooms of this alga, which typically occur in autumn, are associated with fish deaths in this lake. Experiments using 15 phytoplankton and 5 zooplankton isolated from Liyu Lake indicate that these plankton exhibit various susceptibilities to B. braunii. A close correlation between the degree of susceptibility tested in the laboratory and the absence of certain phytoplankton during B. braunii blooms in the lake was observed, suggesting allelopathic effects. Isolation, identification, and verification with authentic compounds indicated that allelochemicals were a mixture of free fatty acids, including a-linolenic, oleic, linolic, and palmitic acids. Compared with other phytoplankton isolates, B. braunii produced significantly higher amounts of free fatty acids, particularly of oleic and a-linolenic acids. The role of these fatty acids in favoring dominance of B. braunii in the natural environment was elucidated.

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Section: Discussionmentioning

confidence: 73%

ALLELOCHEMICALS OF BOTRYOCOCCUS BRAUNII (CHLOROPHYCEAE)¹

Chiang

Huang

2004

Journal of Phycology

117

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“…LA is known to result in loss of manganese from the water-splitting complex [Golbeck et al, 1980] [Garstka and Kaniuga, 1988]; perhaps DPC reduces scatter by bypassing the OEC and thus reducing its influence. Other donor-side inhibition may remain, however [Siegenthaler, 1974] [Venediktov and Krivoshejeva, 1983] [Golbeck and Warden, 1984] [Warden and Csatorday, 1987]. Kinetic results will be discussed subsequently solely in terms of the direct-plotting technique of CornishBowden.…”

Section: Dcip Reduction Kinetics Chapterv Discussionmentioning

confidence: 99%

“…participate in the disruption of chloroplast and thylakoid membrane structure [Cohen et al, 1969] [Shaw et al, 1976[Shaw et al, ][0kamoto et al, 1977 ii.) inhibit the donor complex by various means [Siegenthaler,197 4] [Golbeck et al, 1980] [Venediktov and Krivoshejeva, 1983] [Golbeck and Warden, 1984] [Warden and Csatorday, 1987] [Garstka and Kaniuga, 1988] iii.) stimulate electron flow due to uncoupling of phosphorylation [Cohen et al, 1969][0kamoto and Katoh,1977] [Golbeck et al, 1980], iv.)…”

Section: Stroma Core Complex F -----------8 Nm ------------4mentioning

confidence: 99%

An analysis of the inhibitory effects of linolenic acid upon photosystem II of higher plants

Iven¹

2000

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This study utilizes steady state fluorescence measurements, flash-induced P68Q+ absorption transients, and DCIP reduction kinetics to study the inhibitory effects of linolenic acid (LA) upon Photosystem II (PSII) in whole spinach chloroplasts and insideout wheat thylakoids. It confirms the presence within PSII of LA-induced inhibition of energy trapping and/or primary charge separation (i.e., primary inhibition), in addition to 2 donor side inhibition. The latter is diminished in the presence of 1,5-Diphenylcarbohydrazide (DPC) and probably takes place at the oxygen evolving complex. Primary inhibition, which is more controversial, probably occurs between Ph and ~, with a likely contribution at the level of PSil energy trapping. In addition, the ability of Mg2+ to delay a drop in steady state fluorescence intensity normally associated with thylakoid exposure to LA is explained by the ability of this cation to confer resistance to LA-induced destacking of thylakoid membranes.Steady state fluorescence results in the presence of DCMU, dithionite and LA also support the presence of an additional acceptor between Ph and QA. This acceptor, designated here as "~." is proposed not to be a sequential member of the transport chain, but may be accessible to it via QA when the chain blocked, such as with DCMU. ~-is proposed to exert a coulombic effect upon Ph, thereby affecting the degree of primary charge recombination. It may be related to one of the several acceptors already proposed by others and the need for more study is stressed in order to confirm or refute its existence. I also would like to express appreciation to Chuck Haymond and to the science support services for their assistance in designing and building the log converter amplifier used in the DCIP kinetic experiments. Finally, I would like to thank those around me, both within the university and without, who offered many helpful suggestions and who were a constant source of encouragement. AN ANALYSIS OF THE INHIBITORY EFFECTS OF LINOLENICThis reaction involves the net reduction of NADP+ at the expense of water. It also involves the phosphorylation of ADP to form ATP (not shown) by utilizing a free energy gradient produced in part as protons generated from (2) accumulate on the inner side of the thylakoid membrane. The enzymes in the dark reactions are not membrane-bound, but require the products formed in the light reactions in addition to carbon dioxide:where F-6-P is an abbreviation for fructose-6-phosphate. Equation ( blocking electron transport between QA and QB ( Fig. 1 b ). Atrazine and other triazine herbicides function in a similar manner. Structural similarities relating the physiological activity of these two types of compounds include a carbonyl or equivalent group and a positively charged nitrogen in each [Trebst, 1987].Linolenic Acid. It has long been known that fatty acids, especially unsaturated fatty acids, inhibit photosynthesis when added to functioning systems [Spikes et al., 1955][ Krogmann and Jagendorf, 1959]. This may seem surpri...

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“…Thus, any modifications in the glycolipids of thylakoid membranes would have a detrimental effect on thylakoid functions and the total photosynthetic efficiency of plants. Further, the breakdown of lipids is associated with the release of free fatty acids, some of which are known to inhibit electron transport on the water oxidation side around PS 11 (Goldbeck et al 1980;Venedictov and Krivosheyava 1983;Lindon and Henriques 1991). Any decrease in this lipid content would drastically decrease PS II activity possibly by disturbing the organization of the PS II complexes.…”

Section: Thylakoid Membrane Lipidsmentioning

confidence: 99%

Membrane Lipid Alterations in Heavy Metal Exposed Plants

Devi

Prasad

2004

Heavy Metal Stress in Plants

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INTRODUCTIONLipids are a group of fat and fat-like substances, rich in carbon and hydrogen, that dissolve in organic solvents. They are necessary for maintaining the structural integrity of membranes and constitute approximately 40% of the total dry weight of membranes, the remaining 60% being proteins.The kinds and proportions of lipids to proteins vary with the membrane and the physiological status of the cell. The principal lipid classes of the plasma membrane include phospholipids (65%), glycolipids (20%) and sterols (5%). The four most abundant phospholipids are phosphotidylcholine, phosphotidylethanolamine, phosphotidylglycerol and phosphotidylinositol. Mono-galactosyl diglyceride and digalactosyl-diglyceride, stigmasterol and sitosterol are the most common glycolipids and sterols, respectively. The distribution of these compounds differs with the organelles, depending on their function (Harwood and RusseI1984). LIPID COMPOSITION OF DIFFERENT MEMBRANESThe lipid composition of membranes varies with organelles depending on their structure and function. In plasma membranes approximately half of the dry weight is lipid. The major components include phospholipids (65%), glycolipids (20%) and sterols (5%). In the case of mitochondria, phospholipids comprise a greater portion of total membrane lipid (up to 98%) with phosphotidylcholine and phosphotidylethanolamine as major components. Phosphotidylinositol is concentrated in the outer mitochondrial membrane, whereas diphosphotidylglycerol is found exclusively in the inner mitochondrial membrane, of which it is a major component. Unlike the plasma membrane and mitochondrial membranes, chloroplast membranes are unique in that the major lipid components of M. N. V. Prasad (ed.), Heavy Metal Stress in Plants

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The mechanisms of fatty-acid inhibition of electron transport in chloroplasts

Cited by 19 publications

References 6 publications

ALLELOCHEMICALS OF BOTRYOCOCCUS BRAUNII (CHLOROPHYCEAE)¹

ALLELOCHEMICALS OF BOTRYOCOCCUS BRAUNII (CHLOROPHYCEAE)¹

An analysis of the inhibitory effects of linolenic acid upon photosystem II of higher plants

Membrane Lipid Alterations in Heavy Metal Exposed Plants

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The mechanisms of fatty-acid inhibition of electron transport in chloroplasts

Cited by 19 publications

References 6 publications

ALLELOCHEMICALS OF BOTRYOCOCCUS BRAUNII (CHLOROPHYCEAE)1

ALLELOCHEMICALS OF BOTRYOCOCCUS BRAUNII (CHLOROPHYCEAE)1

An analysis of the inhibitory effects of linolenic acid upon photosystem II of higher plants

Membrane Lipid Alterations in Heavy Metal Exposed Plants

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Product

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ALLELOCHEMICALS OF BOTRYOCOCCUS BRAUNII (CHLOROPHYCEAE)¹

ALLELOCHEMICALS OF BOTRYOCOCCUS BRAUNII (CHLOROPHYCEAE)¹