Light-Induced Production of Singlet Oxygen and Superoxide by the Fungal Toxin, Cercosporin

Daub, Margaret E.; Hangarter, Roger P.

doi:10.1104/pp.73.3.855

Cited by 148 publications

(87 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…After subtracting the background luminosity including endogenous singlet oxygen, it is possible to measure the luminosity intensity generated by the respective concentration of cercosporin which give rise to the individual calibration curves as shown in Figure 4. The luminosity of each parasite The singlet oxygen content was calculated according to the quantum yield of 0.84À0.97 as determined before (17).…”

Section: Quantifying Singlet Oxygen Induced By Cercosporin In P Falcmentioning

confidence: 99%

See 1 more Smart Citation

Cytometric quantification of singlet oxygen in the human malaria parasitePlasmodium falciparum

et al. 2012

View full text Add to dashboard Cite

The malaria parasite Plasmodium falciparum proliferates within human erythrocytes and is thereby exposed to a variety of reactive oxygen species (ROS) such as hydrogen peroxide, hydroxyl radical, superoxide anion, and highly reactive singlet oxygen ( 1 O 2 ). While most ROS are already well studied in the malaria parasite, singlet oxygen has been neglected to date. In this study we visualized the generation of 1 O 2 by live cell fluorescence microscopy using 3-(p-aminophenyl) fluorescein as an indicator dye. While 1 O 2 is found restrictively in the parasite, its amount varies during erythrocytic schizogony. Since the photosensitizer cercosporin generates defined amounts of 1 O 2 we have established a new cytometric method that allows the stage specific quantification of 1 O 2 . Therefore, the parasites were first classified into three main stages according to their respective pixel-area of 200-600 pixels for rings, 700-1,200 pixels for trophozoites and 1,400-2,500 pixels for schizonts. Interestingly the highest mean concentration of endogenous 1 O 2 of 0.34 nM is found in the trophozoites stage, followed by 0.20 nM (ring stage) and 0.10 nM (schizont stage) suggesting that 1 O 2 derives predominantly from the digestion of hemoglobin. ' 2012 International Society for Advancement of Cytometry

show abstract

Section: Quantifying Singlet Oxygen Induced By Cercosporin In P Falcmentioning

confidence: 99%

“…To produce a defined amount of the highly reactive 1 O 2 molecules we used cercosporin, a singlet oxygen producer naturally occurring in the plant pathogenic fungus Cercospora nicotinae (17,18).…”

mentioning

confidence: 99%

Cytometric quantification of singlet oxygen in the human malaria parasitePlasmodium falciparum

et al. 2012

View full text Add to dashboard Cite

show abstract

“…When the unsaturated acyl chains are oxidized, spin labelling experiments showed that the membranes become more rigid at all temperatures and that the membrane phase transformation temperature increased from 12.7° to 20.8°C. In 1983, Daub and Hangarter (118), reported that cercosporin produced superoxide radicals as well as singlet oxygen upon exposure to light in the presence of oxygen. Cercosporin reacted with cholesterol to form the 5 alpha-hydroperoxide of cholesterol.…”

Section: Alpha-terthienyl and Polyacetylenesmentioning

confidence: 99%

Development of Photoactivated Compounds as Pesticides

Heitz

1987

ACS Symposium Series

View full text Add to dashboard Cite

Although light has been known to enhance certain toxic reactions since 1888, the principle was not exploited until after 1970 to any great extent. The greatest concentration of effort has been in the study of photodynamically active dyes, primarily the halogenated fluorescein series, as prospective insecticides. More recently, compounds of plant origin have been isolated, identified, and studied as phototoxins against a wide range of pests, including insects, fungi, and weeds. The main classes studied to this time are the furanocoumarins, thiophenes, acetylenes, extended quinones, and the chlorophyll a intermediates popularized as "laser herbicides." It is apparent that this area of research will expand in the coming years rather than retrench.The expenditure of energy frequently helps to enhance the probability of successfully reaching one's goals in this universe. For as long as chemistry has existed as a science, we have input energy, most frequently heat energy, into chemical reactions to make the molecules or to produce the effects which we wanted. The use of light energy has remained quantitatively a minor component as a means of energy input. This has also been the case with the development of the pesticide industry. Light energy has not been used to drive toxicological reactions or to provide specificity for those reactions to any great extent until the decade of the 70's. Several review chapters have been written covering individual aspects of photodynamically active pesticides (1-8). The purpose of this chapter is to provide a chronological treatment of the development of light as an integral part of the toxicological action of several classes of pesticides; and also, to show the development of the various classes of light activated pesticides relative to each other.

show abstract

“…Photochemical reduction of nitrotetrazolium blue chloride (NTB) was used to determine production by elsinochromes (Daub & Hangarter, 1983). Reactions were carried out in a solution containing 5 mM 3-(N-morpholino) propanesulfonic acid (MOPS), 10 mM methionine (as a reducing agent), 2.5 mM NTB, 2 µM riboflavin or 10 µM of elsinochromes or cercosporin, and/or superoxide dismutase (SOD, 1 mg ml -1 ) or DABCO (1 mM).…”

Section: Detection Of Singlet Oxygen and Superoxide Ionsmentioning

confidence: 99%

“…Production of by elsinochromes was evaluated with a superoxide scavenging assay (Beruchamp & Fridovich, 1971;Daub & Hangarter, 1983) based on its ability to reduce …”

Section: Production Of Reactive Oxygen Species By Elsinochromesmentioning

confidence: 99%

Cellular toxicity of elsinochrome phytotoxins produced by the pathogenic fungus, Elsinoë fawcettii causing citrus scab

Liao

Chung

2007

New Phytologist

View full text Add to dashboard Cite

Summary• Elsinochromes are the red/orange pigments produced by many Elsinoë fungal species and are structurally similar to the phytotoxin, cercosporin. Here, pigments were extracted from cultures of a citrus pathogen, Elsinoë fawcettii and tested for cellular toxicity.• On irradiation with light, elsinochromes rapidly killed suspension cultured citrus and tobacco cells. The toxicity was decreased by adding the singlet oxygen ( 1 O 2 ) quenchers (bixin (carotenoid carboxylic acid), DABCO (1, 4-diazabicyco octane), ascorbate or reduced glutathione). Application of elsinochromes onto rough lemon leaves resulted in necrotic lesions, whereas lesion development was inhibited by the addition of bixin, DABCO or ascorbate, but not α -tocopherol. Incubation of rough lemon leaf discs with elsinochromes in the light induced a steady increase of electrolyte leakage.• Compared with two photosensitizing compounds, hematoporphyrin and cercosporin, the accumulation of 1 O 2 induced by elsinochromes after irradiation was indicated by successful detection of the cholesterol oxidation product, 5 α -hydroperoxide. Addition of a potent quencher, β -carotene prevented 5 α -hydroperoxide production. Elsinochromes generated superoxide ions ( ), whereas accumulation of was blocked by addition of the superoxide dismutase, a scavenger of , but not the 1 O 2 -quencher, DABCO. Our study indicated that elsinochromes are functioning as photosensitizing compounds that produce 1 O 2 and , and exert toxicity to plant cells.

show abstract

Light-Induced Production of Singlet Oxygen and Superoxide by the Fungal Toxin, Cercosporin

Cited by 148 publications

References 12 publications

Cytometric quantification of singlet oxygen in the human malaria parasitePlasmodium falciparum

Cytometric quantification of singlet oxygen in the human malaria parasitePlasmodium falciparum

Development of Photoactivated Compounds as Pesticides

Cellular toxicity of elsinochrome phytotoxins produced by the pathogenic fungus, Elsinoë fawcettii causing citrus scab

Contact Info

Product

Resources

About