Probing the role of endogenous ethylene in the degreening of citrus fruit with ethylene antagonists

1993 ◽  
Vol 12 (3) ◽  
pp. 325-329 ◽  
Author(s):  
E. E. Goldschmidt ◽  
M. Huberman ◽  
R. Goren
Keyword(s):  
Citrus Fruit ◽  
Endogenous Ethylene ◽  
Ethylene Antagonists

Antioxidative Role of Synthetic and Natural Ascorbic Acid (Vitamin C) in Metabolic Pathways of A Biological System

2021 ◽  
Vol 15 (12) ◽  
pp. 3143-3143
Author(s):  
Naveed Shuja
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Silica Gel ◽  
Biological System ◽  
Metabolic Pathways ◽  
Citrus Fruit ◽  
Pharmaceutical Preparations ◽  
Metabolic Reaction ◽  
Fresh Vegetables

The properties of a substance are determined by the structure of its component molecules. Ascorbic acid occurs abundantly in fresh fruit, especially blackcurrants, citrus fruit and strawberries, and in most fresh vegetables; good sources are broccoli and peppers. It is destroyed by heat and is not well stored in the body3. Ascorbic acid is a good reducing agent and facilitates many metabolic reaction and repair processes. In pharmaceutical preparations and fruit juices, ascorbic acid is readily separated from other compounds by TLC on silica gel and quantitated directly by absorption at 254nm. Serum and plasma may be deproteinized with twice the volume of methanol or ethanol.

scholarly journals CsWRKY25 Improves Resistance of Citrus Fruit to Penicillium digitatum via Modulating Reactive Oxygen Species Production

2022 ◽  
Vol 12 ◽  
Author(s):  
Wenjun Wang ◽  
Ting Li ◽  
Qi Chen ◽  
Shixiang Yao ◽  
Lili Deng ◽  
...  
Keyword(s):  
Target Genes ◽  
Citrus Fruit ◽  
Cinnamyl Alcohol Dehydrogenase ◽  
Transcription Level ◽  
Pr Genes ◽  
Citrus Peel ◽  
Regulated Expression ◽  
Transient Overexpression ◽  
Species Production

WRKY transcription factors (TFs) play crucial roles in the regulation of biotic stress. Citrus is the most productive fruit in the world. It is of great value to investigate the regulatory molecular mechanism of WRKYs in improving disease resistance. In this research, the transcription level of CsWRKY25 was upregulated in P. digitatum infected citrus peel, and CsWRKY25 activated the expression of three target genes (RbohB, RbohD, and PR10). Besides, the Agrobacterium-mediated transient overexpression of CsWRKY25 has also been shown to enhance resistance to P. digitatum in citrus, and caused the accumulation of hydrogen peroxide and lignin. The accumulation of ROS also activated the antioxidant system, the catalase (CAT), peroxidase (POD), and cinnamyl alcohol dehydrogenase (CAD) genes were significant upregulated, leading to activation of antioxidant enzymes. In addition, the up-regulated expression of MPK5 and MPK6 genes suggested that the regulatory role of CsWRKY25 might be related to the phosphorylation process. In conclusion, CsWRKY25 could enhance the resistance to P. digitatum via modulating ROS production and PR genes in citrus peel.

scholarly journals Hesperidin and SARS-CoV-2: New Light on the Healthy Functions of Citrus Fruit

2020 ◽  
Author(s):  
Paolo Bellavite ◽  
Alberto Donzelli
Keyword(s):  
Immune System ◽  
Citrus Sinensis ◽  
Viral Infections ◽  
Citrus Fruit ◽  
Short Review ◽  
Citrus Fruits ◽  
Early Proteins ◽  
Main Protease ◽  
The Many

Among the many approaches to COVID-19 prevention, the possible role of diet has so far been somewhat marginal. Nutrition is very rich in substances with a potential beneficial effect on health and some of these could have an antiviral action or in any case be important in modulating the immune system and in defending cells from the oxidative stress associated with infection. This short review draws the attention on some components of Citrus fruits and especially of the orange (Citrus sinensis), well known for its vitamin content, but less for the function of its flavonoids. Among the latter, hesperidin has recently attracted the attention of researchers, because it binds to the key proteins of the SARS-CoV-2 virus. Several computational methods, independently applied by different researchers, showed that hesperidin has a low binding energy both with the coronavirus "spike" protein, and with the main protease that transforms the early proteins of the virus (pp1a and ppa1b) into the complex responsible for viral replication. The affinity of hesperidin for these proteins is comparable if not superior to that of common chemical antivirals. The preventive efficacy of vitamin C, at dosage attainable by diet, against viral infections is controversial, but recent reviews suggest that this substance may be useful in case of increased stress on the immune system. Finally, the reasons that suggest undertaking appropriate research on the Citrus fruits addition in the diet, as a complementary prevention and treatment of COVID-19, are discussed.

scholarly journals Interactions of Cloud Proteins, Pectins and Pectinesterases in Flocculation of Citrus Cloud

2002 ◽  
Author(s):  
Ilan Shomer ◽  
Louise Wicker ◽  
Uzi Merin ◽  
William L. Kerr
Keyword(s):  
Structural Changes ◽  
Specific Interaction ◽  
Light And Electron Microscopy ◽  
Citrus Fruit ◽  
Heat Inactivation ◽  
Complex Process ◽  
Neutral Sugars ◽  
Important Quality

The overall objective was to understand the cloud flocculation of citrus juice by characterization of the interactions between proteins and pectins, and to determine the role of PE isozymes in catalyzing this phenomenon. Specific objectives were to: 1. identify/characterize cloud-proteins in relation to their coagulable properties and affinity to pectins; 2. to determine structural changes of PME and other proteins induced by cation/pectin interactions; 3. localize cloud proteins, PME and bound protein/pectates in unheated and pasteurized juices; 4. to create "sensitized" pectins and determine their effect on clarification. The original objectives were not changed but the methods and approach were modified due to specific research requirements. Two i postulates were: 1. there is a specific interaction of cloud proteins with de-esterified regions of ! pectin and this contributes to cloud loss; 2. isozymes of pectin-methyl-esterase (PME) vary in efficiency to create sensitized pectins. The appearance of citrus fruit juice is an important quality factor and is determined by the color and turbidity that .are conferred by the suspended particles, i.e., by the cloud and its homogeneity. Under some circumstances the cloud tend to flocculate and the juice clarifies. The accepted approach to explain the clarification is based on pectin demethoxylation by PME that promotes formation of Ca-pectate. Therefore, the juice includes immediate heat-inactivation upon ~ squeezing. Protein coagulation also promotes cloud instability of citrus fruit extracts. However, the clarification mechanism is not fully understood. Information accumulated from several laboratories indicates that clarification is a more complex process than can be explained by a single mechanism. The increasing trend to consume natural-fresh juice emphasizing the importance of the knowledge to assure homogeneity of fresh juice. The research included complementary directions: Conditions that induce cloud-instability of natural- juice [IL]. Evaluate purification schemes of protein [USA]. Identifications of proteins, pectin and neutral sugars ([IL]; Structure of the cloud components using light and electron microscopy and immuno-labeling of PME, high-methoxyl-pectin (HMP) and low-methoxyl-pectin (LMP); Molecular weight of calcium sensitized pectins [US]; Evaluation of the products of PME activity [US]. Fractions and size distribution and cloud components [IL-US]. The optimal pH activity of PME is 7 and the flocculation pH of the cloud is 3-4. Thus, the c roles of PME, proteins and pectins in the cloud instability, were studied in pH ranges of 2- 7. The experiments led to establish firstly repeatable simulate conditions for cloud instability [IL]. Thermostable PME (TS-PE) known to induce cloud instability, but also thermolabile forms of PME (TL-PE) caused clarification, most likely due to the formation and dissolution of inactive :. PE-pectin complexes and displacement of a protective colloid from the cloud surface [US]. Furthermore, elimination of non-PME protein increases TS-PE activity, indicating that non-PME proteins moderate PME activity [US]. Other experiments Concomitantly with the study of the PME activity but promotes the association of cloud-proteins to pectin. Adjusting of the juice pH to f 7 retains the cloud stability and re-adjusting of the pH to 40% DE reacts to immuno-labeling in the cloud fragments, whereas

scholarly journals Oxidative Metabolism in ‘Valencia’ Sweet Orange (Citrus sinensis Osbeck) Abscission Zone Tissue Treated with the Abscission Agent 5-Chloro-3-Methyl-4-Nitro-1H-Pyrazole

HortScience ◽  
2016 ◽  
Vol 51 (4) ◽  
pp. 377-382 ◽  
Author(s):  
Naveen Kumar ◽  
Robert C. Ebel
Keyword(s):  
Oxidative Metabolism ◽  
Indole Acetic Acid ◽  
Specific Activity ◽  
Sweet Orange ◽  
Malonic Dialdehyde ◽  
Citrus Fruit ◽  
Abscission Zone ◽  
Specific Activities ◽  
Orange Trees

5-Chloro-3-methyl-4-nitro-1H-pyrazole (CMNP) is an abscission agent, standardized for the mechanical harvesting of late season ‘Valencia’ sweet oranges in Florida. This work was conducted to investigate the role of CMNP to induce oxidative stress in the abscission zone (AZ) of ‘Valencia’ sweet orange. Fully mature ‘Valencia’ sweet orange trees in a commercial grove were sprayed with 2.0 mm of CMNP. The experiment was repeated three times during the Apr.–May 2013 harvest season. Fruit were harvested at 0, 1, 2, and 3 days after CMNP application. Hydrogen peroxide (H2O2) concentration and malonic dialdehyde (MDA) concentration, as well as superoxide dismutase (SOD), ascorbate peroxidase (APOD), glutathione reductase (GR), peroxidase (POD), and lipoxygenase (LOX) specific activities were measured 0, 1, 2, and 3 days after CMNP treatment (DAT). Rate of lipid peroxidation remains unchanged throughout the abscission period. However, LOX activity increased 1 DAT in AZ of treated fruit, which might produce jasmonic acid (JA), known to promote abscission in citrus. Levels of H2O2 were similar in the AZ of control and treated fruit except at 3 DAT. The specific activity of SOD declined at 2 DAT, which showed compromised SOD defense against superoxide radicals (O·−). APOD activity declined sharply at 3 DAT. Interestingly, GR activity was 1.9-fold higher in CMNP-treated fruit at 3 DAT. Higher GR and low APOD activity reflects limited functioning of the APOD/GR cycle (e.g., APOD and GR) in scavenging of H2O2 at 3 DAT. Guaiacol POD activity transiently increased at 1 DAT and then declined. POD plays an important role in cell wall lignification and indole acetic acid (IAA) oxidation. The decline in POD activity may cause a decrease in lignification while higher activity made the AZ sensitive to ethylene and thus promote abscission in citrus fruit. This work also showed that CMNP-induced abscission is a collaborative effort of oxidative metabolism in flavedo tissue (FT) and AZ.

The role of endogenous ethylene in the expansion of Helianthus annuus leaves

1997 ◽  
Vol 75 (3) ◽  
pp. 501-508 ◽  
Author(s):  
Siew Hwee Lee ◽  
David M. Reid
Keyword(s):  
Carboxylic Acid ◽  
Helianthus Annuus ◽  
Acid Treatment ◽  
Leaf Growth ◽  
Leaf Expansion ◽  
Silver Thiosulphate ◽  
Ethylene Concentration ◽  
Endogenous Ethylene ◽  
Ethylene Action

The possible role of ethylene in leaf expansion of the primary leaves of sunflower plants (Helianthus annuus) was studied. Our lowest application of ethephon promoted expansion of primary leaves. Higher concentrations of ethephon, and a range of concentrations of 1-aminocyclopropane-1-carboxylic acid, increased endogenous ethylene concentration and caused a reduction in the area of the primary leaves. The inhibition in leaf expansion induced by ethephon and 1-aminocyclopropane-1-carboxylic acid was reversed by pretreating the plants with an inhibitor of ethylene action, namely silver thiosulphate. Treating leaves with lower concentrations of aminoefhoxyvinylglycine reduced ethylene production and stimulated leaf expansion. This effect of aminoethoxyvinylglycine could be nullified by pretreating the plants with 1-aminocyclopropane-1-carboxylic acid. Treatment with silver thiosulphate enhanced leaf expansion. This indicates that endogenous ethylene normally plays a significant role in leaf expansion. Flooded and gravistimulated plants produced more ethylene and had smaller leaves. This could suggest that the increased ethylene is the main cause of the slowed leaf growth, however, only in some cases were we able to partially reverse the effect of flooding with silver thiosulphate. This indicates that there are probably many factors, in addition to increased ethylene, that inhibit leaf expansion in flooded and gravistimulated plants. Key words: ethylene, leaf expansion.

scholarly journals Controlling Strategies of Citrus to Increase The Yield in The Country: A step Towards The Fight Against COVID-19

2021 ◽  
Vol 910 (1) ◽  
pp. 012045
Author(s):  
Ghulam Abbas ◽  
Duraid K.A. Al-Taey ◽  
Saad S.M. Al-Azawi ◽  
Mohammad Mehdizadeh ◽  
Razia A. M. Qureshi ◽  
...  
Keyword(s):  
Vitamin C ◽  
Citrus Fruit ◽  
Good Health ◽  
Large Area ◽  
The World ◽  
Antiviral Function ◽  
Citrus Production ◽  
Infection And Inflammation ◽  
The Many

Abstract Citrus (oranges, lemon, mandarin, limes and tangarines) has significant nutritional value in human foods. It is rich source of vitamin C, sugar, organic acids, amino acids, minerals like Ca, Mg and various other phytochemicals (flavonoids, hesperidin etc) compounds that are responsible for good health. Citrus is growing in more than one forty countries of the world including Pakistan, Brazil, China, Mexico, USA, Spain and India.Viral infection and inflammation triggers the production of oxygen free radicals and these radicals severely damage the cells, however hesperidin and vitamin C is reported to counteract these damages. Intake of plentiful citrus fruits is one of amongst the many possible approaches to prevent from COVID-19 role of nutrition. Citrus fruit are very rich in important substances with a potential beneficial for health such as modulating the immunity and in protecting cells from oxidative stress related with infection. Flavonoids and hesperidin two major key compound found in citrus have affinity to treat Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Hesperidin has a low binding energy, both with the coronavirus “spike” protein, and with the fundamental protease that alters the primary proteins of the virus (pp1a and ppa1b) into the complex liable for viral replication hence these compounds could work as an antiviral function. Pakistan is amongst top ten citrus producers in the world. Citrus is one of the best commercial fruits of Pakistan cultivated on a large area, however, in Pakistan yield of citrus has been affected due to attack of insects and pathogens (nematode, fungal, bacterial and viral) which causes heavy losses both in quality and quantity. The purpose of this article is to focusing on the controlling the pathogens of citrus to boost citrus production in country as these beneficial plants are well known for its essential vitamin and flavonoid contents to control COVID-19.

scholarly journals Re-evaluation of ethylene role in Arabidopsis cauline leaf abscission induced by water stress and rewatering

2021 ◽  
Author(s):  
Shimon Meir ◽  
Sonia Philosoph-Hadas ◽  
Shoshana Salim ◽  
Adi Segev ◽  
Joseph Riov
Keyword(s):  
Water Stress ◽  
Ethylene Production ◽  
Leaf Abscission ◽  
Wild Type ◽  
Cauline Leaf ◽  
Arabidopsis Mutants ◽  
Endogenous Ethylene ◽  
Exogenous Ethylene ◽  
Established Role

ABSTRACTPatharkar and Walker (2016) reported that cauline leaf abscission in Arabidopsis is induced by a cycle of water stress and rewatering, which is regulated by the complex of INFLORESCENCE DEFICIENT IN ABSCISSION (IDA), HAESA (HAE), and HAESA-LIKE2 (HSL2) kinases. However, they stated without presenting experimental results that ethylene is not involved in this process. Since this statement contradicts the well-established role of ethylene in organ abscission induced by a cycle of water stress and rewatering, our present study was aimed to re-evaluate the possible involvement of ethylene in this process. For this purpose, we examined the endogenous ethylene production during water stress and following rewatering, as well as the effects of exogenous ethylene and 1-methylcyclopropene (1-MCP), on cauline leaf abscission of Arabidopsis wild type. Additionally, we examined whether this stress induces cauline leaf abscission in ethylene-insensitive Arabidopsis mutants. The results of the present study demonstrated that ethylene production rates increased significantly in cauline leaves at 4 h after rewatering of stressed plants, and remained high for at least 24 h in plants water-stressed to 40 and 30% of system weight. Ethylene treatment applied to well-watered plants induced cauline leaf abscission, which was inhibited by 1-MCP. Cauline leaf abscission was also inhibited by 1-MCP applied during a cycle of water stress and rewatering. Finally, no abscission occurred in two ethylene-insensitive mutants, ein2-1 and ein2-5, following a cycle of water stress and rewatering. Taken together, these results clearly indicate that ethylene is involved in Arabidopsis cauline leaf abscission induced by water stress.One sentence summaryUnlike Patharker and Walker (2016), our results show that ethylene is involved in Arabidopsis cauline leaf abscission induced by water stress and rewatering, similar to leaf abscission in other plants.

Involvement of ethylene in ectomycorrhiza formation and dichotomous branching of roots of mugo pine seedlings

1989 ◽  
Vol 67 (2) ◽  
pp. 477-482 ◽  
Author(s):  
L. A. Rupp ◽  
K. W. Mudge ◽  
F. B. Negm
Keyword(s):  
Root Growth ◽  
Laccaria Laccata ◽  
Pinus Mugo ◽  
Silver Thiosulfate ◽  
Root Branching ◽  
Pine Seedlings ◽  
Mycorrhiza Formation ◽  
Endogenous Ethylene ◽  
Ethylene Action

The role of ethylene in mycorrhiza formation and root development on axenically grown seedlings of Pinus mugo Turra var. mugo was examined. Mycorrhizal formation by Laccaria laccata and Pisolithus tinctorius in a defined liquid medium was associated with increased ethylene production. Ethephon (100 μM) stimulated dichotomous branching of roots inoculated with P. tinctorius, but had no effect on those inoculated with L. laccata, or on uninoculated roots. Ethephon had no effect on the percentage of susceptible roots that became mycorrhizal with either fungus. The inhibitor of ethylene action, silver thiosulfate, had no significant effect on mycorrhiza formation by P. tinctorius, but it did show a trend toward decreased mycorrhiza formation by L. laccata when applied at concentrations of 10 μM or higher. Silver thiosulfate at 100 or 500 μM slightly increased dichotomous root branching of seedlings inoculated with either fungus, but these concentrations also caused blackening of root meristems and inhibition of root growth. These results are consistent with the interpretation that endogenous ethylene may influence mycorrhiza formation and associated changes in root morphology.

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