scholarly journals NADPH Oxidase (Rboh) Activity is Up Regulated during Sweet Pepper (Capsicum annuum L.) Fruit Ripening

Antioxidants ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 9 ◽  
Author(s):  
Ángela Chu-Puga ◽  
Salvador González-Gordo ◽  
Marta Rodríguez-Ruiz ◽  
José M. Palma ◽  
Francisco J. Corpas

In plants, NADPH oxidase (NOX) is also known as a respiratory burst oxidase homolog (Rboh). This highly important enzyme, one of the main enzymatic sources of superoxide radicals (O2•−), is involved in the metabolism of reactive oxygen and nitrogen species (ROS and RNS), which is active in the non-climacteric pepper (Capsicum annuum L.) fruit. We used sweet pepper fruits at two ripening stages (green and red) to biochemically analyze the O2•−-generating Rboh activity and the number of isozymes during this physiological process. Malondialdehyde (MDA) content, an oxidative stress marker, was also assayed as an index of lipid peroxidation. In red fruits, MDA was observed to increase 2-fold accompanied by a 5.3-fold increase in total Rboh activity. Using in-gel assays of Rboh activity, we identified a total of seven CaRboh isozymes (I–VII) which were differentially modulated during ripening. CaRboh-III and CaRboh-I were the most prominent isozymes in green and red fruits, respectively. An in vitro assay showed that CaRboh activity is inhibited in the presence of nitric oxide (NO) donors, peroxynitrite (ONOO−) and glutathione (GSH), suggesting that CaRboh can undergo S-nitrosation, Tyr-nitration, and glutathionylation, respectively. In summary, this study provides a basic biochemical characterization of CaRboh activity in pepper fruits and indicates that this O2•−-generating Rboh is involved in nitro-oxidative stress associated with sweet pepper fruit ripening.

Antioxidants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 374 ◽  
Author(s):  
Marta Rodríguez-Ruiz ◽  
Salvador González-Gordo ◽  
Amanda Cañas ◽  
María Jesús Campos ◽  
Alberto Paradela ◽  
...  

During the ripening of sweet pepper (Capsicum annuum L.) fruits, in a genetically controlled scenario, enormous metabolic changes occur that affect the physiology of most cell compartments. Peroxisomal catalase gene expression decreases after pepper fruit ripening, while the enzyme is also susceptible to undergo post-translational modifications (nitration, S-nitrosation, and oxidation) promoted by reactive oxygen and nitrogen species (ROS/RNS). Unlike most plant catalases, the pepper fruit enzyme acts as a homodimer, with an atypical native molecular mass of 125 to 135 kDa and an isoelectric point of 7.4, which is higher than that of most plant catalases. These data suggest that ROS/RNS could be essential to modulate the role of catalase in maintaining basic cellular peroxisomal functions during pepper fruit ripening when nitro-oxidative stress occurs. Using catalase from bovine liver as a model and biotin-switch labeling, in-gel trypsin digestion, and nanoliquid chromatography coupled with mass spectrometry, it was found that Cys377 from the bovine enzyme could potentially undergo S-nitrosation. To our knowledge, this is the first report of a cysteine residue from catalase that can be post-translationally modified by S-nitrosation, which makes it especially important to find the target points where the enzyme can be modulated under either physiological or adverse conditions.


2018 ◽  
Vol 120 ◽  
pp. S106-S107
Author(s):  
Salvador González-Gordo ◽  
Rocío Bautista ◽  
M. Gonzalo Claros ◽  
Alberto Paradela ◽  
Antonio Ramos ◽  
...  

2017 ◽  
Vol 6 (2) ◽  
Author(s):  
Rosa Raybaudi-Massilia ◽  
Alírica I. Suárez ◽  
Francisco Arvelo ◽  
Alexandra Zambrano ◽  
Felipe Sojo ◽  
...  

Alcoholic and aqueous extracts were obtained from red sweet pepper (Capsicum annuum L.) by different methodologies to evaluate their cytotoxic, antioxidant and antimicrobial properties. Alcoholic extracts (MFP, MSd, SFP, SDP, SSd) from fresh red sweet pepper (FP) and dry pulp (DP) and seed (Sd) were obtained by maceration (M) and Soxhlet (S) equipment using methanol as extraction solvent; whereas aqueous extracts (LFP, LSd) were obtained by decoction followed by lyophilization (L). Human tumoral cell lines from breast (MCF-7 and SKBr3), prostate (PC3) and cervix (HeLa), and fibroblasts (as control) were used to determine the cytotoxic properties by the MTT assay. Antioxidant and antimicrobial properties were determined by DPPH and disc diffusion method, respectively. The extracts SDP and SFP showed the higher cytotoxic activity. The SDP extract had a significant (P < 0.05) in-vitro effect on HeLa (1.9 ± 1.4 µg/mL) and PC3 (< 1 µg/mL) cells with a moderated impact on fibroblasts (26.1 ± 1.2 µg/mL); whereas, SFP had a significant (p < 0.05) effect on MCF-7 cell line (2.1 ± 1.2 µg/mL) with a moderated impact on fibroblasts (25.9 ± 1.0 µg/mL). The higher antioxidant activity was found for MFP (80.3 ± 0.2%) and SFP extracts (75.5 ± 0.5%). Mild antimicrobial activity was only observed for alcoholic extracts. The results showed the potential of red sweet pepper (C. annuum L.) as a source of antioxidant and cytotoxic compounds, and suggest the need of further studies to isolate and characterize the bioactive compounds that impart those properties.


1978 ◽  
Vol 26 (1) ◽  
pp. 59-63
Author(s):  
J. Baer ◽  
L. Smeets

During 1976, plants of the sweet-pepper variety Verbeterde Glas [Improved Glass] were placed in growth rooms at 55, 80 or 95% relative humidity, at the onset of flowering. The flowers were artificially pollinated until flower drop, and the plants were moved to the glasshouse for the fruit-ripening period. Fruit set was not influenced by relative humidity, but seed set increased with increasing humidity. Time from pollination to harvest was significantly shorter at 95% relative humidity. (Abstract retrieved from CAB Abstracts by CABI’s permission)


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