| cellular toxicity of elsinochrome phytotoxins produced by the pathogenic fungus, elsinoë fawcettii causing citrus scab. | 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 ... | 2008 | 17953652 |
| inhibitory activity against plant pathogenic fungi of extracts from myoporum bontioides a. gray and indentification of active ingredients. | in order to understand the bioactivity of myoporum bontioides a. gray against plant pathogens and determine its active ingredients, the inhibitory activities of methanol extracts from m. bontioides against fusarium oxysporum f. sp. niveum (e. f. smith) snyder & hansen, pestalotia mangiferae p. henn., thielaviopsis paradoxa (de seynes) v. hohnel, colletotrichum musae (berk. & m. a. curtis) v. arx, alternaria alternata (fr.) keissler, mycosphaerella sentina (fr.) schroter and sphaceloma fawcettii ... | 2008 | 18069657 |
| genetic dissection defines the roles of elsinochrome phytotoxin for fungal pathogenesis and conidiation of the citrus pathogen elsinoë fawcettii. | elsinochrome pigments produced by many phytopathogenic elsinoë spp. are nonhost-selective toxins which react with oxygen molecules after light activation to produce highly toxic reactive oxygen species. the structures and chemical properties of four derivatives are well known. however, the biological roles of elsinochromes in fungal pathogenesis are poorly understood. many isolates of elsinoë fawcettii causing citrus scab are able to produce elsinochromes under axenic conditions. in this article ... | 2008 | 18321192 |
| elsinoë fawcettii and elsinoë australis: the fungal pathogens causing citrus scab. | elsinoë fawcettii and e. australis are important pathogens of citrus. both species are known to produce red or orange pigments, called elsinochrome. elsinochrome is a nonhost-selective phytotoxin and is required for full fungal virulence and lesion formation. this article discusses the taxonomy, epidemiology, genetics and pathology of the pathogens. it also provides a perspective on the cellular toxicity, biosynthetic regulation and pathological role of elsinochrome phytotoxin. taxonomy: elsinoë ... | 2010 | 21199563 |
| nonhost-associated proliferation of intrahyphal hyphae of citrus scab fungus elsinoe fawcettii: refining the perception of cell-within-a-cell organization. | ultrastructural aspects of intrahyphal hyphae formation were investigated in elsinoe fawcettii by transmission electron microscopy. desiccated and hydrated cultures of e. fawcettii hyphae in liquid and solid media were prepared to determine the effects of water/nutrient availability and media fluidity on the formation of intrahyphal hyphae of the fungus. in all the culture conditions, intrahyphal hyphae were observed in enclosing hyphae. electron-transparent hyphal cell walls clearly delimited i ... | 2007 | 17137785 |
| transcriptional regulation of elsinochrome phytotoxin biosynthesis by an efste12 activator in the citrus scab pathogen elsinoë fawcettii. | elsinochrome (esc), produced by the citrus pathogen elsinoë fawcettii, is a nonhost-selective, light-dependent, polyketide-derived phytotoxin and plays a crucial role for full virulence. the biosynthesis of esc is regulated by a wide array of environmental stimuli and is primarily governed by the pathway-specific tsf1 transcription regulator whose coding gene is clustered with the efpks1 gene encoding a polyketide synthase and other biosynthetic genes in the genome. in this report, an efste12 ge ... | 2010 | 20965063 |
| pathotypes and genetic relationship of worldwide collections of elsinoë spp. causing scab diseases of citrus. | two scab diseases are recognized currently on citrus: citrus scab, caused by elsinoë fawcettii, and sweet orange scab, caused by e. australis. because the two species cannot be reliably distinguished by morphological or cultural characteristics, host range and molecular methods must be used to identify isolates. four pathotypes of e. fawcettii and two of e. australis have been described to date based on host range. the host specificity and genetic relationships among 76 isolates from argentina, ... | 2009 | 19453232 |
| determination of a transcriptional regulator-like gene involved in biosynthesis of elsinochrome phytotoxin by the citrus scab fungus, elsinoë fawcettii. | elsinochromes are nonhost-selective, light-activated, polyketide-derived toxins produced by many phytopathogenic elsinoë species. we recently showed that the polyketide synthase-encoding gene efpks1 is essential for elsinochrome biosynthesis in the citrus scab fungus elsinoë fawcettii. sequence analysis beyond the efpks1 gene identified nine putative orfs: four genes, designated rdt1, tsf1, prf1 and ect1, all encode polypeptides likely to have biosynthetic or efflux functions; five additional ge ... | 2008 | 18957608 |