Role of organic acids in the integration of cellular redox metabolism and mediation of redox signalling in photosynthetic tissues of higher plants

2018 ◽  
Vol 122 ◽  
pp. 74-85 ◽  
Author(s):  
Abir U. Igamberdiev ◽  
Natalia V. Bykova
Keyword(s):  
Organic Acids ◽  
Higher Plants ◽  
Redox Metabolism ◽  
Cellular Redox ◽  
Redox Signalling

scholarly journals Overexpression of plastid terminal oxidase in Synechocystis sp. PCC 6803 alters cellular redox state

2017 ◽  
Vol 372 (1730) ◽  
pp. 20160379 ◽  
Author(s):  
Kathleen Feilke ◽  
Ghada Ajlani ◽  
Anja Krieger-Liszkay
Keyword(s):  
Higher Plants ◽  
Photosynthetic Apparatus ◽  
Oxygenic Photosynthesis ◽  
Terminal Oxidase ◽  
Cellular Redox ◽  
Excess Electrons ◽  
Plastid Terminal Oxidase ◽  
Absorption Measurements ◽  
Pcc 6803

Cyanobacteria are the most ancient organisms performing oxygenic photosynthesis, and they are the ancestors of plant plastids. All plastids contain the plastid terminal oxidase (PTOX), while only certain cyanobacteria contain PTOX. Many putative functions have been discussed for PTOX in higher plants including a photoprotective role during abiotic stresses like high light, salinity and extreme temperatures. Since PTOX oxidizes PQH 2 and reduces oxygen to water, it is thought to protect against photo-oxidative damage by removing excess electrons from the plastoquinone (PQ) pool. To investigate the role of PTOX we overexpressed rice PTOX fused to the maltose-binding protein (MBP-OsPTOX) in Synechocystis sp. PCC 6803, a model cyanobacterium that does not encode PTOX. The fusion was highly expressed and OsPTOX was active, as shown by chlorophyll fluorescence and P 700 absorption measurements. The presence of PTOX led to a highly oxidized state of the NAD(P)H/NAD(P) + pool, as detected by NAD(P)H fluorescence. Moreover, in the PTOX overexpressor the electron transport capacity of PSI relative to PSII was higher, indicating an alteration of the photosystem I (PSI) to photosystem II (PSII) stoichiometry. We suggest that PTOX controls the expression of responsive genes of the photosynthetic apparatus in a different way from the PQ/PQH 2 ratio. This article is part of the themed issue ‘Enhancing photosynthesis in crop plants: targets for improvement’.

Physiological Role of Cyclic Electron Flow in Higher Plants

2012 ◽  
Vol 30 (1) ◽  
pp. 100
Author(s):  
Wei HUANG ◽  
Shi-Bao ZHANG ◽  
Kun-Fang CAO
Keyword(s):  
Higher Plants ◽  
Electron Flow ◽  
Physiological Role ◽  
Cyclic Electron Flow

scholarly journals Differential Expression of Peroxisomal Proteins in Distinct Types of Parotid Gland Tumors

2021 ◽  
Vol 22 (15) ◽  
pp. 7872
Author(s):  
Malin Tordis Meyer ◽  
Christoph Watermann ◽  
Thomas Dreyer ◽  
Steffen Wagner ◽  
Claus Wittekindt ◽  
...  
Keyword(s):  
Redox Balance ◽  
Matrix Proteins ◽  
Parotid Tumor ◽  
Gene Expressions ◽  
Tissue Samples ◽  
Cellular Redox ◽  
Tumor Subtypes ◽  
Parotid Tumors ◽  
Aggressive Tumors

Salivary gland cancers are rare but aggressive tumors that have poor prognosis and lack effective cure. Of those, parotid tumors constitute the majority. Functioning as metabolic machinery contributing to cellular redox balance, peroxisomes have emerged as crucial players in tumorigenesis. Studies on murine and human cells have examined the role of peroxisomes in carcinogenesis with conflicting results. These studies either examined the consequences of altered peroxisomal proliferators or compared their expression in healthy and neoplastic tissues. None, however, examined such differences exclusively in human parotid tissue or extended comparison to peroxisomal proteins and their associated gene expressions. Therefore, we examined differences in peroxisomal dynamics in parotid tumors of different morphologies. Using immunofluorescence and quantitative PCR, we compared the expression levels of key peroxisomal enzymes and proliferators in healthy and neoplastic parotid tissue samples. Three parotid tumor subtypes were examined: pleomorphic adenoma, mucoepidermoid carcinoma and acinic cell carcinoma. We observed higher expression of peroxisomal matrix proteins in neoplastic samples with exceptional down regulation of certain enzymes; however, the degree of expression varied between tumor subtypes. Our findings confirm previous experimental results on other organ tissues and suggest peroxisomes as possible therapeutic targets or markers in all or certain subtypes of parotid neoplasms.

Chemistry of oxylipin pathways in marine diatoms

2007 ◽  
Vol 79 (4) ◽  
pp. 481-490 ◽  
Author(s):  
Angelo Fontana ◽  
Giuliana d'Ippolito ◽  
Adele Cutignano ◽  
Antonio Miralto ◽  
Adrianna Ianora ◽  
...  
Keyword(s):  
Higher Plants ◽  
Larval Growth ◽  
Marine Macroalgae ◽  
High Concentration ◽  
Marine Diatoms ◽  
Fatty Acid Derivatives ◽  
The Family ◽  
Hydrolysis Of ◽  
Catalyzed Oxidation

Oxylipins are important signal transduction molecules widely distributed in animals and plants where they regulate a variety of events associated with physiological and pathological processes. The family embraces several different metabolites that share a common origin from the oxygenase-catalyzed oxidation of polyunsaturated fatty acids. The biological role of these compounds has been especially studied in mammalians and higher plants, although a varied and very high concentration of these products has also been reported from marine macroalgae. This article gives a summary of our results concerning the oxylipin chemistry of marine diatoms, a major class of planktonic microalgae that discourage predation from their natural grazers, zooplanktonic copepods, using chemical warfare. These apparently harmless microscopic cells produce a plethora of oxylipins, including short-chain unsaturated aldehydes, hydroxyl-, keto-, and epoxyhydroxy fatty acid derivatives, that induce reproductive failure in copepods through abortions, congenital malformations, and reduced larval growth. The biochemical process involved in the production of these compounds shows a simple regulation based on decompartmentation and mixing of preexisting enzymes and requires hydrolysis of chloroplast-derived glycolipids to feed the downstream activities of C16 and C20 lipoxygenases.

After-Cooking Discoloration of Potatoes Role of the Organic Acids

1964 ◽  
Vol 29 (5) ◽  
pp. 555-564 ◽  
Author(s):  
E. G. HEISLER ◽  
JAMES SICILIANO ◽  
C. F. WOODWARD ◽  
W. L. PORTER
Keyword(s):  
Organic Acids
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