biosynthetic relationships among the secalonic acids. isolation of emodin, endocrocin and secalonic acids from pyrenochaeta terrestris and aspergillus aculeatus.cynodontin, emodin, endocrocin and secalonic acids a, e and g have been isolated from five strains of pyrenochaeta terrestis. aspergillus aculeatus produces emodin, endocrocin and secalonic acids b, d and f. no cynodontin was detected. isolation of emodin in small amounts supports previous evidence that it is an intermediate in secalonic acid biosynthesis. isolation of cynodontin and endocrocin, which are co-produced with secalonic acids in other organisms, suggests that these compounds are form ...1979541252
antibiotic activity of the pyrenocines.pyrenocine a, a phytotoxin produced by pyrenochaeta terrestris (hansen) gorenz, walker and larson, possesses general antibiotic activity against plants, fungi, and bacteria. effective doses for 50% inhibition (ed50s) are 4 micrograms/ml for onion seedling elongation; 14, 20, 20, and 25 micrograms/ml for the germination of asexual spores of fusarium oxysporum f. sp. cepae, fusarium solani f. sp. pisi, mucor hiemalis, and rhizopus stolonifer, respectively. pyrenocine a also inhibits the linear myc ...19873594310
ultrastructure and lipid changes in pyrenochaeta terrestris during aging. 19734700352
ultrastructural comparisons of fungus hyphal cells using frozen-etched replicas and thin sections of the fungus pyrenochaeta terrestris. 19684871973
regulation of induced cellulase synthesis in pyrenochaeta terrestris gorenz et al. by utilizable carbon compounds. 19665929151
induction and repression of endopolygalacturonase synthesis by pyrenochaeta terrestris. 19665962580
post-aromatic deoxygenation in polyketide biosynthesis: reduction of aromatic rings in the biosyntheses of fungal melanin and anthraquinone.two enzyme reactions involved in the post-aromatic deoxygenation process of fungal melanin and pigments were studied from the viewpoint of enzymic reduction of aromatic rings. hydroxynaphthalene reductase that catalyzes reduction of the aromatic rings of 1,3,6,8-tetrahydroxynaphthalene and 1,3,8-trihydroxynapthalene was partially purified from phialophora lagerbergii and characterized. emodin deoxygenase of pyrenochaeta terrestris that catalyzes deoxygenation of emodin to afford chrysophanol was ...19938293526
the pigment of phoma terrestris hansen. 196013786771
the biosynthesis of the pyrenocines in cultures of pyrenochaeta terrestris.[(14)c]acetate, [(14)c]formate, and methyl[(14)c]methionine all serve as precursors of pyrenocines a, b, and c when added to cultures of pyrenochaeta terrestris (hansen) gorenz, walker, and larson, the pathogen responsible for disease known as pink root of onion (allium cepa l.). this information supports the hypothesis that these metabolites are methyl-substituted polyketides in origin. pyrenocine a arises from acetate via uncharacterized intermediates and is subsequently converted to pyrenocin ...198516664393
segregation (?) in phoma terrestris. 193017790516
fungal parasitism of heterodera glycines eggs as influenced by egg age and pre-colonization of cysts by other fungi.the objective of this study was to determine the effect of egg age and pre-colonization of cysts by a saprophytic or parasitic fungus on parasitism of heterodera glycines eggs by other parasitic fungi. in agar and in soil tests, fungi generally parasitized more eggs in early developmental stages than eggs containing a juvenile. the effect of pre-colonization of cysts by a fungus on parasitism of eggs by other fungi depended on the fungi involved. in most cases, pre-colonization of cysts by an un ...200319262761
viability of heterodera glycines exposed to fungal filtrates.filtrates from nematode-parasitic fungi have been reported to be toxic to plant-parasitic nematodes. our objective was to determine the effects of fungal filtrates on second-stage juveniles and eggs of heterodera glycines. eleven fungal species that were isolated from cysts extracted from a soybean field in florida were tested on j2, and five species were tested on eggs in vitro. each fungal species was grown in czapek-dox broth and malt extract broth. no toxic activity was observed for fungi gr ...200019270965
pathogenicity of fungi to eggs of heterodera glycines.twenty-one isolates of 18 fungal species were tested on water agar for their pathogenicity to eggs of heterodera glycines. an egg-parasitic index (epi) for each of these fungi was recorded on a scale from 0 to 10, and hatch of nematode eggs was determined after exposure to the fungi on water agar for 3 weeks at 24 c. the epi for verticillium chlamydosporium was 7.6, and the fungus reduced hatch 74%. pyrenochaeta terrestris and two sterile fungi also showed a high epi and reduced hatch 42-73%. ar ...199619277130
fungi associated with females and cysts of heterodera glycines in a florida soybean field.fungal colonization was determined for females and cysts of heterodera glycines on soybean roots or in rhizosphere soil from a florida soybean field. a total of 1,620 females and cysts were examined in 1991, and 1,303 were examined in 1992. more than 35 species of fungi were isolated from females and cysts. the frequency of fungi colonizing white and yellow females was low, but a high frequency of fungi was encountered in brown cysts, which increased with time of exposure of the cysts to the soi ...199419279895
studies on the host-finding mechanisms of neotylenchus linfordi.the plant-parasitic nematode, neotylenchus linlordi, congregated around colonies or filtrates from mycelia of gliocladium roseum, rhizoctonia solani, pyrenochaeta terrestris and chaetomium indicum. the average time required for the nematodes to reach the fungal colonies ranged from less than 4 hr for g. roseum to 20 hr for r. solani. nematodes first circled near the point of introduction, then moved toward the fungus or filtrate. several methods of measuring the response of n. linfordi to g. ros ...197019322281
a rapid method for isolation of total dna from pathogenic filamentous plant fungi.dna isolation from some fungal organisms of agronomic importance is difficult because they have cell walls or capsules that are relatively unsusceptible to lysis. we have developed a fast dna isolation protocol for fusarium oxysporum, which causes fusarium wilt disease in more than 100 plant species, and for pyrenochaeta terrestris, which causes pink root in onions. this protocol was based on the sodium dodecyl sulfate/phenol method, without beta-mercaptoethanol and without maceration in liquid ...201020198572
systematic reappraisal of species in phoma section paraphoma, pyrenochaeta and pleurophoma.sequence data from the 18s nrdna (ssu) and 28s nrdna (lsu) regions of isolates of phoma section paraphoma were compared with those of representative isolates of the morphologically similar anamorph genera pleurophoma and pyrenochaeta and of the type species of phoma sections phoma, pilosa and plenodomus. phoma section paraphoma was found to be highly polyphyletic within the pleosporales and only distantly related to phoma section phoma. the genus paraphoma, which is based on paraphoma radicina, ...201020943506
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