| fungal fimbriae. i. structure, origin, and synthesis. | fine hair-like appendages on the cell walls of the another smut ustilago violacea are described. these hairs are termed fimbriae because of their close similarity to the fimbriae (pili) found on certain gram-negative bacteria. cells of u. violacea may carry more than 200 fimbriae varying in length from about 0.5 mum to over 10 mum, and having a diameter of about 60-70 a. some fimbriae produce knobs similar to those found on bacterial sex fimbriae. log-phase cells are the most densely fimbriated, ... | 1975 | 47260 |
| genetic and cell cycle analysis of a smut fungus (ustilago violacea). | | 1977 | 875744 |
| fungal fimbriae. ii. their role in conjugation in ustilago violacea. | during conjugation in the anther smut fungus ustilago violacea cells of opposite mating type first pair tightly and then develop a conjugation tube or bridge between them. the cells of both mating types are covered in long fine hairs or fimbriae, some of which appear to end in knobs. experiments involving enzyme treatments of the cell surface indicate that these fimbriae do not play an essential role in cell pairing, instead pairing seems to be initiated when one or both mating types produce amo ... | 1975 | 1122428 |
| evidence for a new kind of regulatory gene controlling expression of genes for morphogenesis during the cell cycle in ustilago violacea. | | 1975 | 1183810 |
| somatic nuclear division in the sporidia of ustilago violacea. iii. ultrastructural observations. | the paper provides detailed ultrastructural observations on nuclear division in the smut fungus ustilago violacea and is based on previous light-microscopic work outlining the division in living and stained cells. the division as in many other basidiomycetes is not intranuclear, but occurs within a partially disrupted membrane. the division takes place after migration of most of the nucleus into the bud cell, after limited breakdown of the nuclear membrane, and after the formation of a spindle b ... | 1976 | 1260542 |
| somatic nuclear division in the sporidia of ustilago violacea. iv. microtubules and the spindle-pole body. | in unbudded cells of the anther smut fungus ustilago violacea there is a dome-shaped spindle-pole body (spb) consisting of a core 0.1 mum in diameter surrounded by a ribosome-free region 0.3-0.4 mum in diameter lying in a pocket of the nuclear membrane. after budding the nucleus moves towards the bud and begins to rotate rapidly. at about this stage the spb divides into two parallel bars each about 0.1-0.15 mum in diameter and 0.3 mum long, separated by a distance of about 0.3 mum. microtubules ... | 1976 | 1260543 |
| transmission of mitochondrial dna in ustilago violacea. | mitochondrial dna (mtdna) restriction fragment length polymorphisms (rflps) were used as genetic markers for following mitochondrial transmission in the basidiomycete ustilago violacea. yeast-like cells of opposite mating types (a1 and a2) were mated on 2% water agar and were treated with alpha-tocopherol to induce formation of dikaryotic hyphae. upon depletion of the alpha-tocopherol, the hyphae budded off haploid cells with parental nuclear genotypes. these cells were examined for mitochondria ... | 1992 | 1358468 |
| introduction and maintenance of prokaryotic dna in ustilago violacea. | a strain of the basidiomycete, ustilago violacea, was transformed with a prokaryotic plasmid, pmp4-1, which confers resistance to neomycin. u. violacea transformants were selected at a frequency of 5 per microgram pmp4-1 dna. such transformants were at least 8-fold more resistant to neomycin than was the untransformed recipient u. violacea. enzyme activity associated with the neomycin resistance gene was also found in the transformants. southern dna-dna hybridization detected pmp4-1-derived sequ ... | 1990 | 1366759 |
| acquisition of mitochondrial dna by a transformation vector for ustilago violacea. | plasmid puch1 is a 5.2-kb puc18 construct bearing the hygb gene fused to a promoter from cochliobolus heterostrophus. haploid cells of the basidiomycete, ustilago violacea, were transformed with this plasmid. in addition to multiple integrations of plasmid sequences into u. violacea nuclear dna, vector sequences independent of the nuclear genome were indicated by southern-blot analysis using all or part of puch1 as a probe. hybridization also revealed intact puch1 and several larger derivatives ... | 1991 | 2013405 |
| preparation of protoplasts of ustilago violacea for transformation and pulse-field electrophoresis. | | 1989 | 2631789 |
| a high efficiency transformation system for the basidiomycete ustilago violacea employing hygromycin resistance and lithium-acetate treatment. | a basidiomycete phytopathogenic fungus, ustilago violacea, was transformed with puch1, a bacterial plasmid containing the hygromycin (hyg)-resistance hygb gene fused to a promoter from the ascomycete cochliobolus heterostrophus. after lithium acetate/polyethylene glycol treatment of whole sporidial cells, u. violacea transformants appeared on hyg-agar at a frequency of 60-80 per microgram puch1 dna. the hyg phenotype was 100% stable in these transformants for at least 30 generations of mitotic g ... | 1989 | 2792770 |
| protection of ustilago violacea from toluidine blue photosensitization and hydrogen peroxide induced killing and mitotic recombination by carotenes. | | 1988 | 3222340 |
| somatic nuclear division in the sporidia of ustilago violacea. i. acetic orcein staining. | | 1972 | 4113457 |
| somatic nuclear division in the sporidia of ustilago violacea. ii. observations on living cells with phase-contrast and fluorescence microscopy. | | 1974 | 4134060 |
| transcription and translation of the sex message in the smut fungus ustilago violacea. ii. the effects of inhibitors. | | 1974 | 4424117 |
| the control of karyogamy in somatic cells of ustilago violacea. | | 1974 | 4426926 |
| conjugation in ustilago violacea. i. morphology. | | 1974 | 4822787 |
| transcription and translation of the sex message in the smut fungus, ustilago violacea. i. the effect of ultraviolet light. | | 1974 | 4830830 |
| 'fimbriae' in the fungus ustilago violacea. | | 1974 | 4847938 |
| recombination in ustilago violacea after liquid nitrogen refrigeration. | | 1972 | 5086105 |
| sexual and parasexual analysis of ustilago violacea. | | 1969 | 5367373 |
| ultraviolet light sensitive mutants of ustilago violacea. | | 1970 | 5512564 |
| effect of ultraviolet light on nuclear fusion in ustilago violacea. | | 1969 | 5803404 |
| the genetics an biochemistry of urease in ustilago violacea. | two complementing loci in different linkage groups of the basidiomycete ustilago violacea are involved in urease activity: a structural one (ure-1) and a second inferred to involve a permease (ure-2) locus. two types of complementing mutations occur in the structural locus: null activity (ure-la) and obviously reduced activity (ure-1b). the ure-2 mutants lacked urease activity in vivo on the phenol red-urea est medium, but gave extracts with wild-type activity. extracts from wild-type strains ga ... | 1981 | 7337690 |
| evidence that fimbriae of the smut fungus microbotryum violaceum contain rna. | the cells of the fungus microbotryum violaceum produce many long, fine surface hairs that are similar in size and morphology to bacterial pili or fimbriae. these fungal fimbriae are assembled from 74 kda glycoprotein subunits. we now present evidence that these fimbriae also have a rna component. isopycnic centrifugation of fimbriae in caesium chloride produced one band at a density intermediate to that of protein and nucleic acid. the absorbance spectrum of the intact fimbriae was consistent wi ... | 1994 | 7528083 |
| the gamma-tubulin-encoding gene from the basidiomycete fungus, ustilago violacea, has a long 5'-untranslated region. | the gene (gamma-tub) encoding gamma-tubulin (gamma-tub) was isolated from a cosmid library constructed for ustilago violacea by using a pcr-amplified dna fragment as a probe. about 2.8 kb of dna sequence was analyzed and found to encode a protein of 469 amino acids highly homologous to the gamma-tub from other organisms. there were eight introns interrupting the coding sequence. a 'tata'-like sequence was found 389 bp upstream from the initial met codon. no polyadenylation signal was found in th ... | 1993 | 8299946 |
| fungal fimbriae are composed of collagen. | fungal fimbriae are surface appendages that were first described on the haploid cells of the smut fungus, microbotryum violaceum. they are long (1-20 microm), narrow (7 nm) flexuous structures that have been implicated in cellular functions such as mating and pathogenesis. since the initial description, numerous fungi from all five phyla have been shown to produce fimbriae on their extracellular surfaces. the present study analyses the protein component of m.violaceum fimbriae. the n-terminus an ... | 1996 | 8887535 |
| sex determination in dioecious silene latifolia. effects of the y chromosome and the parasitic smut fungus (ustilago violacea) on gene expression during flower development. | we have embarked on a molecular cloning approach to the investigation of sex determination in silene latifolia poiret, a dioecious plant species with morphologically distinguishable sex chromosomes. one of our key objectives was to define a range of genes that are up-regulated in male plants in response to y chromosome sex-determination genes. here we present the characterization of eight male-specific cdna sequences and classify these according to their expression dynamics to provide a range of ... | 1997 | 9232878 |
| spatial expression dynamics of men-9 delineate the third floral whorl in male and female flowers of dioecious silene latifolia. | sex determination in silene latifolia is controlled by heteromorphic sex chromosomes. female flowers have five fused carpels and ten arrested stamen primordia. the male-determining y chromosome overrides female development to suppress carpel formation and promote stamen development. the isolation and characterization of two s. latifolia. male enhanced cdnas, men-9a and men-9b, which probably represent different alleles of a novel gene are reported here. men-9a and men-9b share 91.8% coding seque ... | 1997 | 9263457 |
| isolation and characterization of microsatellite loci in the anther smut fungus microbotryum violaceum. | | 1998 | 9633108 |
| host and parasite population structure in a natural plant-pathogen system | we investigated the genetic population structure in a metapopulation of the plant silene latifolia (caryophyllaceae) and its fungal pathogen microbotryum violaceum (ustilaginales), a pollinator-borne disease. population structure of the host plant was estimated using allozyme markers and that of the fungus by microsatellites. both host and parasite showed significant differentiation, but parasite populations were 12 times more strongly differentiated than those of the hosts. we found significant ... | 1999 | 10336705 |
| random amplified polymorphic dna analysis of ustilago violacea. | isolates of the two mating type strains of the basidiomycete phytopathogen ustilago violacea (pers.) roussel [a.k.a microbotryum violaceum (pers.:pers.) deml and oberw] are restricted in their host range to one or a few species of caryophyllaceae (pinks). molecular genetics maps in this species are commonly constructed by analyzing the segregation of restriction fragment length polymorphisms (rflps) among the progeny of a sexual cross and more recently through electrophoretic karyotypes and chro ... | 1999 | 10415498 |
| genetic isolation among host races of the anther smut fungus microbotryum violaceum on three host plant species. | genetic isolation among strains of the plant pathogenic fungus microbotryum violaceum on three species of its host plants was examined. fungal strains collected from a sympatric population of all three host plant species were examined for their ability to infect the other host plant species and to cross-conjugate among each other. genetic isolation was investigated from the distribution of neutral microsatellite alleles. since this is a pollinator-transmitted disease, we examined movement patter ... | 1999 | 10506472 |
| use of internal transcribed spacer primers and fungicide treatments to study the anther-smut disease, microbotryum violaceum (=ustilago violacea), of white campion silene alba (=silene latifolia). | we report the construction and use of polymerase chain reaction (pcr) primers for detection of microbotryum violaceum in silene alba. such primers show that the pathogen is present in the aboveground bud meristems, flower pedicels, and flower-stem internodes but not in the flowering-stem leaves and roots of flowering plants. use of primers also showed that the pathogen was absent from plants that had been inoculated with the fungus but remained healthy. the fungicides folicur and bayleton cured ... | 1999 | 10568785 |
| genetics of ustilago violacea. xxxv. transposition in haploid and diploid sporidia and germinating teliospores. | ustilago violacea sporidia of the white (w) mad strain (a-2 w lys-3 ino-1 thi) incubated on minimal medium containing 100 mm kclo3 (potassium chlorate) produced only colonies with the pink phenotype. sporidia from these colonies retained their pink color on complex medium. sporidia of the diploid d1 strain (a-1 y nic-1 thi/a-2 w met-1 arg-f chl70 thi) and of the diploid d2 strain (a-1 y his-1 glu-1 thi/a-2 w lys-3 ino-1 thi) produced pink colonies on complex medium. streaks of diploid d1 sporidi ... | 2000 | 10777446 |
| intratetrad mating, heterozygosity, and the maintenance of deleterious alleles in microbotryum violaceum (=ustilago violacea). | the mating system of microbotryum violaceum was investigated in populations that are polymorphic for mating-type bias, where individuals produce viable haploids of only one of the two required mating types. the cause of mating-type bias was identified as deleterious recessive alleles linked to mating type. maintenance of the deleterious alleles was promoted by early conjugation among products of single meioses, such that the duration of the free-living haploid stage is minimized. this developmen ... | 2000 | 11012726 |
| differences in population structure of the anther smut fungus microbotryum violaceum on two closely related host species, silene latifolia and s. dioica. | we investigated the genetic population structure of the sexually transmitted plant pathogen, the fungus microbotryum violaceum, on the two closely related host species silene latifolia and s. dioica using microsatellite markers. we found strong deviations from hardy-weinberg expectations, with significant heterozygote deficiency in almost all populations. fungal strains from the two host species were differentiated, and these host races differed in amount of variation within populations and diff ... | 2001 | 11298945 |
| the beta-tubulin-encoding gene from microbotryum violaceum: unusual in a variety of ways. | the beta-tubulin gene of microbotryum violaceum was sought originally for its potential use in improving the transformation of this organism. the gene was cloned and its nucleotide sequence was determined. the gene was predicted to encode a 444-residue protein with strong sequence similarity to other beta-tubulins. the coding region was 2.85 kb, much larger than the corresponding genes from other organisms. this was due to the large number of introns in this gene, as determined by comparison of ... | 2001 | 11453255 |
| dimorphic mating-type chromosomes in the fungus microbotryum violaceum. | fungi often mate as haploids, and sex chromosomes (i.e., mating-type chromosomes) that are dimorphic for their size or overall dna content have never been reported in this kingdom. using electrophoretic techniques for karyotype analysis, a highly dimorphic chromosome pair that determines mating compatibility is shown to occur in populations of the fungus microbotryum violaceum. this substantiates the evolution of such dimorphism as a general feature associated with haploid determination of matin ... | 2002 | 11861552 |
| isolates of microbotryum violaceum from north american host species are phylogenetically distinct from their european host-derived counterparts. | microbotryum violaceum is a basidiomycete that infects the anthers of its caryophyllaceae host species. individual fungal isolates are host limited, though they are not morphologically distinct. this study used variable regions of the highly conserved gamma-tubulin, beta-tubulin, and ribosomal rna-encoding genes to determine the relationships among m. violaceum fungal isolates from different host species and different geographical locations. phylogenetic trees from intron nucleotide sequences in ... | 2002 | 12069548 |
| transmission genetics of microbotryum violaceum (ustilago violacea): a case history. | | 2002 | 12236055 |
| a plant pathogen reduces the enemy-free space of an insect herbivore on a shared host plant. | an important mechanism in stabilizing tightly linked host-parasitoid and prey-predator interactions is the presence of refuges that protect organisms from their natural enemies. however, the presence and quality of refuges can be strongly affected by the environment. we show that infection of the host plant silene latifolia by its specialist fungal plant pathogen microbotryum violaceum dramatically alters the enemy-free space of a herbivore, the specialist noctuid seed predator hadena bicruris, ... | 2002 | 12427312 |
| intraspecific competition and mating between fungal strains of the anther smut microbotryum violaceum from the host plants silene latifolia and s. dioica. | we studied intraspecific competition and assortative mating between strains of the anther smut fungus microbotryum violaceum from two of its host species, silene latifolia and s. dioica. specifically, we investigated whether strains from allopatric host populations have higher competitive ability on their native host species and show positive assortative mating. in general, strains isolated from s. latifolia outcompeted strains isolated from s. dioica on both host species, but in female hosts, h ... | 2003 | 12778546 |
| karyotypic similarity identifies multiple host-shifts of a pathogenic fungus in natural populations. | the detection of incipient host-shifts is important to the study of emergent diseases because it allows the examination of ecological and genetic conditions that favor novel inter-species transmission. mixed populations of silene latifolia and silene vulgaris were investigated for the putative occurrence of host-shifts by the fungal plant pathogen microbotryum violaceum (the cause of anther-smut disease) between s. latifolia (a common host for the pathogen) and s. vulgaris (a rare host). samples ... | 2003 | 12797978 |
| dynamics of multiple infection and within-host competition by the anther-smut pathogen. | infection of one host by multiple pathogen genotypes represents an important area of pathogen ecology and evolution that lacks a broad empirical foundation. multiple infection of silene latifolia by microbotryum violaceum was studied under field and greenhouse conditions using the natural polymorphism for mating-type bias as a marker. field transmission resulted in frequent multiple infection, and each stem of the host was infected independently. within-host diversity of infections equaled that ... | 2003 | 12856241 |
| isolation and characterization from pathogenic fungi of genes encoding ammonium permeases and their roles in dimorphism. | nutrient sensing plays important roles in fungal development in general, and specifically in critical aspects of pathogenicity and virulence, for both animal and plant pathogens. dimorphic pathogens such as the phytopathogenic smut fungi, ustilago maydis and microbotryum violaceum, must switch from a yeast-like to a filamentous form in order to cause disease. two genes encoding methylammonium permeases (meps) were identified from each of these latter fungi and all the encoded proteins were most ... | 2003 | 14507379 |
| morphological development of anthers induced by the dimorphic smut fungus microbotryum violaceum in female flowers of the dioecious plant silene latifolia. | when inoculated with the dimorphic smut fungus microbotryum violaceum (pers.) g. deml and oberwinkler, the female flower of the dioecious plant silene latifolia (miller) e.h.l. krause develops anther-like structures filled with spores instead of pollen grains. using natural scanning electron microscopy, nomarski interference microscopy, and fluorescence microscopy, we investigated the morphological modifications of the host plant resulting from this parasitism and the localization of smut hyphae ... | 2003 | 14551772 |
| analysis of members of the silene latifolia cys2/his2 zinc-finger transcription factor family during dioecious flower development and in a novel stamen-defective mutant ssf1. | sex determination in dioecious silene latifolia poir. is governed by the inheritance of heteromorphic sex chromosomes. in male plants the y chromosome influences two aspects of male organogenesis, the continued differentiation of stamen primordia and male fertility, and one aspect of female organogenesis, the arrest of development of the pistil. s. latifolia is susceptible to infection by the parasitic smut fungus ustilago violacea, which induces stamen development in genetically female plants. ... | 2004 | 15703927 |
| expression of the floral b-function gene slm2 in female flowers of silene latifolia infected with the smut fungus microbotryum violaceum. | silene latifolia is a dioecious plant in which sex is determined by x and y chromosomes. expression of the b-function gene slm2, an ortholog of pistillata (pi) in arabidopsis, was examined by in situ hybridization. slm2 was not expressed in suppressed stamens of female flowers, but was expressed in developing stamens of smut-infected female flowers. these results indicate that the control of slm2 is independent of the presence of the y chromosome. smut-infected females provide a useful system fo ... | 2005 | 15755743 |
| maintenance of sex-linked deleterious alleles by selfing and group selection in metapopulations of the phytopathogenic fungus microbotryum violaceum. | microbotryum violaceum is a fungus that causes the sterilizing anther smut disease in many caryophyllaceae. its diploid teliospores are heterozygous at the mating-type locus, normally producing equal proportions of haploid sporidia of the two mating types. however, natural populations contain high frequencies of individuals producing sporidia of only one mating type. this mating-type ratio bias is caused by the presence of deleterious alleles at haploid phase ("haplo-lethals") linked to the mati ... | 2005 | 15795854 |
| siderophore accumulation and phytopathogenicity in microbotryum violaceum. | we investigated the role of the siderophore rhodotorulic acid (ra) accumulation in the host-pathogen interaction of microbotryum violaceum and silene latifolia. while the wild-type m. violaceum accumulated ra in the culture medium in response to iron stress, the monogenic mutant 45 of m. violaceum did not accumulate detectable amounts of ra under limiting iron supply. genetic analysis showed the mutant 45 locus to be 3.8 cm from the centromere, endorsing the pericentric gene clustering of m. vio ... | 2005 | 15896989 |
| differential expression of mepa, mepc and smte during growth and development of microbotryum violaceum. | many fungi require a dimorphic switch from budding to filamentous growth to cause infection. although the control of dimorphism has been elucidated for organisms such as saccharomyces cerevisiae and ustilago maydis, almost nothing is known about the control of mating and dimorphism in microbotryum violaceum. m. violaceum mepa, mepc and smte are homologs of genes whose encoded products act as, or interact with, components of the mapk and camp-pka pathways, conserved pathways that regulate mating ... | 2005 | 16392249 |
| mimicry in plant-parasitic fungi. | mimicry is the close resemblance of one living organism (the mimic) to another (the model), leading to misidentification by a third organism (the operator). similar to other organism groups, certain species of plant-parasitic fungi are known to engage in mimetic relationships, thereby increasing their fitness. in some cases, fungal infection can lead to the formation of flower mimics (pseudo flowers) that attract insect pollinators via visual and/or olfactory cues; these insects then either tran ... | 2006 | 16553849 |
| a gravity model for the spread of a pollinator-borne plant pathogen. | many pathogens of plants are transmitted by arthropod vectors whose movement between individual hosts is influenced by foraging behavior. insect foraging has been shown to depend on both the quality of hosts and the distances between hosts. given the spatial distribution of host plants and individual variation in quality, vector foraging patterns may therefore produce predictable variation in exposure to pathogens. we develop a "gravity" model to describe the spatial spread of a vector-borne pla ... | 2006 | 16947105 |
| antagonistic pleiotropy may help population-level selection in maintaining genetic polymorphism for transmission rate in a model phytopathogenic fungus. | it has been shown theoretically that the conditions for the maintenance of polymorphism at pleiotropic loci with antagonistic effects on fitness components are rather restrictive. here, we use a metapopulation model to investigate whether antagonistic pleiotropy could help maintain polymorphism involving common deleterious alleles in the phytopathogenic fungus microbotryum violaceum. this fungus causes anther smut disease of the caryophyllaceae. a previous model has shown that the sex-linked del ... | 2007 | 17021614 |
| evolution of reproductive isolation within a parasitic fungal species complex. | despite important advances in the last few years, the evolution of reproductive isolation (ri) remains an unresolved and critical gap in our understanding of speciation processes. in this study, we investigated the evolution of ri among species of the parasitic fungal species complex microbotryum violaceum, which is responsible for anther smut disease of the caryophyllaceae. we found no evidence for significant positive assortative mating by m. violaceum even over substantial degrees of genetic ... | 2007 | 17598756 |
| expressed sequences tags of the anther smut fungus, microbotryum violaceum, identify mating and pathogenicity genes. | the basidiomycete fungus microbotryum violaceum is responsible for the anther-smut disease in many plants of the caryophyllaceae family and is a model in genetics and evolutionary biology. infection is initiated by dikaryotic hyphae produced after the conjugation of two haploid sporidia of opposite mating type. this study describes m. violaceum ests corresponding to nuclear genes expressed during conjugation and early hyphal production. | 2007 | 17692127 |
| multiple infections by the anther smut pathogen are frequent and involve related strains. | population models of host-parasite interactions predict that when different parasite genotypes compete within a host for limited resources, those that exploit the host faster will be selected, leading to an increase in parasite virulence. when parasites sharing a host are related, however, kin selection should lead to more cooperative host exploitation that may involve slower rates of parasite reproduction. despite their potential importance, studies that assess the prevalence of multiple genoty ... | 2007 | 18020704 |
| antimicrobial prenylated dihydrochalcones from eriosema glomerata. | two new natural dihydrochalcones exhibiting antimicrobial properties together with six known compounds were isolated from the cameroonian medicinal plant eriosema glomerata. the structures of the new dihydrochalcones were elucidated as 2',4'-dihydroxy-4-methoxy-3'-( gamma, gamma-dimethylallyl)dihydrochalcone and 2',4'-dihydroxy-3'-( gamma, gamma-dimethylallyl)dihydrochalcone by detailed spectroscopic analysis. the two new dihydrochalcones, named erioschalcones a ( 1) and b ( 2), demonstrated sig ... | 2008 | 18203062 |
| new mono- and dimeric members of the secalonic acid family: blennolides a-g isolated from the fungus blennoria sp. | blennolides a-g (2-8), seven unusual chromanones, were isolated together with secalonic acid b (1) from blennoria sp., an endophytic fungus from carpobrotus edulis. this is the first reported isolation of the blennolides 2 and 3 (hemisecalonic acids b and e), the existence of which as the monomeric units of the dimeric secalonic acids had long been postulated. a compound of the proposed structure 4 (beta-diversonolic ester) will need to be revised, as its reported data do not fit those of the es ... | 2008 | 18425741 |
| bioactive isocoumarins isolated from the endophytic fungus microdochium bolleyi. | three new isocoumarin derivatives ( 2- 4) were isolated together with monocerin ( 1) from microdochium bolleyi, an endophytic fungus from fagonia cretica, a herbaceous plant of the semiarid coastal regions of gomera. compounds 2 and 3 are both 12-oxo epimers of 1, and 4 is a ring-opened derivative of 1. the structures were elucidated by detailed spectroscopic analysis and comparison with reported data. the absolute configurations were determined by a modified mosher's method. compounds 1, 3, and ... | 2008 | 18510362 |
| disease status and population origin effects on floral scent:: potential consequences for oviposition and fruit predation in a complex interaction between a plant, fungus, and noctuid moth. | in the silene latifolia-hadena bicruris nursery pollination system, the hadena moth is both pollinator and seed predator of its host plant. floral scent, which differs among s. latifolia individuals and populations, is important for adult hadena to locate its host. however, the success of moth larvae is strongly reduced if hosts are infected by the anther smut fungus microbotryum violaceum, a pathogen that is transmitted by flower visitors. there were no qualitative differences between the scent ... | 2009 | 19241105 |
| a superman-like gene is exclusively expressed in female flowers of the dioecious plant silene latifolia. | to elucidate the mechanism(s) underlying dioecious flower development, the present study analyzed a superman (sup) homolog, slsup, which was identified in silene latifolia. the sex of this plant is determined by heteromorphic x and y sex chromosomes. it was revealed that slsup is a single-copy autosomal gene expressed exclusively in female flowers. introduction of a genomic copy of slsup into the arabidopsis thaliana sup (sup-2) mutant complemented the excess-stamen and infertile phenotypes of s ... | 2009 | 19406862 |
| ring b aromatic steroids from an endophytic fungus, colletotrichum sp. | the new (22e,24r)-3-acetoxy-19(10-->6)-abeo-ergosta-5,7,9,22-tetraen-3beta-ol (1) and the known (22e,24r)-19(10-->6)-abeo-ergosta-5,7,9,22-tetraen-3beta-ol (2), two interesting ergosteroids with rare aromatized ring b, together with seven known derivatives, namely (22e,24r)-ergosta-5,7,22-trien-3beta-ol (3), (22e,24r)-ergosta-4,7,22-trien-3-one (4), (22e,24r)-ergosta-4,6,8(14),22-tetraen-3-one (5), (22e,24r)-5alpha,8alpha-epidioxyergosta-6,22-dien-3beta-ol (6), (22e,24r)-ergosta-7,22-dien-3beta, ... | 2009 | 19967971 |
| hybrid sterility and inviability in the parasitic fungal species complex microbotryum. | microbotryum violaceum, the anther-smut fungus, forms a complex of sibling species which specialize on different plants. previous studies have shown the presence of partial ecological isolation and f1 inviability, but did not detect assortative mating apart from a high selfing rate. we investigated other post-mating barriers and show that f1 hybrid sterility, the inability of gametes to mate, increased gradually with the increasing genetic distance between the parents. f2 hybrids showed a reduce ... | 2009 | 19228274 |
| diversonol and blennolide derivatives from the endophytic fungus microdiplodia sp.: absolute configuration of diversonol. | chemical investigation of the fungal strain microdiplodia sp. isolated from the shrub lycium intricatum led to the isolation of four new compounds: a hexahydroxanthone (2), a 2,3-dihydrochroman-4-one (3), a 7-oxoxanthone derivative (4), and a 1,4-oxazepan-7-one (5). the relative configurations of the new compounds were determined by intensive nmr investigations, notably noesy experiments at different temperatures. the absolute configurations of the well-known fungal metabolite diversonol (1) and ... | 2011 | 21244021 |
| [genetic polymorphism of microbotryum violaceum s. i. isolates collected from different plant species on the territory of russia]. | the present-day studies in the field of systematics and phylogeny of microorganisms, fungi, in particular, are characterized by a wide use of new approaches and methods of molecular biology. the use of a diversity of genetic markers permits a distinct differentiation of closely related species into individual evolutionary independent lines. it is shown in this work that all microbotryum violaceum s. l. isolates studied by us are divided into five evolutionary groups according to the host plant. | 2010 | 21261069 |
| bioactive aromatic derivatives from endophytic fungus, cytospora sp. | two new benzyl gamma-butyrolactone analogues, (r)-5-((s)-hydroxy(phenyl)-methyl)dihydrofuran-2(3h)-one (1) and its 6-acetate (2), and a new naphthalenone derivative (8), together with eight additional known aromatic derivatives, (s)-5-((s)-hydroxy(phenyl)-methyl)dihydrofuran-2(3h)-one (3), (s)-5-benzyl-dihydrofuran-2(3h)-one (4), 5-phenyl-4-oxopentanoic acid (5), gamma-oxo-benzenepentanoic acid methyl ester (6), 3-(2,5-dihydro-4-hydroxy-5-oxo-3-phenyl-2-furyl)propionic acid (7), (3r)-5-methylmel ... | 2011 | 21615028 |
| anther smuts of caryophyllaceae: molecular analyses reveal further new species. | recent collections of microbotryum (pucciniomycotina, basidiomycota) specimens inhabiting anthers of different caryophyllaceous host plants were analysed using lm and electron microscopy, as well as molecular phylogenetic analyses using rdna (its and lsu) sequences. the phylogenetic relationships of caryophyllaceous anther parasites are discussed. three new species, microbotryum adenopetalae, m. minuartiae, and m. silenes-acaulis, are described based on morphological, ecological, and molecular c ... | 2008 | 18951773 |
| the ecology and genetics of a host shift: microbotryum as a model system. | the need to prevent and cure emerging diseases often precludes their continuing study in situ. we present studies on the process of disease emergence by host shifts using the model system of anther-smut disease (microbotryum violaceum) on the plant genus silene (caryophyllaceae). this system has little direct social impact, and it is readily amenable to experimental manipulation. our microevolutionary studies have focused on the host shift of microbotryum from silene alba (=latifolia; white camp ... | 2002 | 18707452 |
| spatial and temporal heterogeneity explain disease dynamics in a spatially explicit network model. | there is an increasing recognition that individual-level spatial and temporal heterogeneity may play an important role in metapopulation dynamics and persistence. in particular, the patterns of contact within and between aggregates (e.g., demes) at different spatial and temporal scales may reveal important mechanisms governing metapopulation dynamics. using 7 years of data on the interaction between the anther smut fungus (microbotryum violaceum) and fire pink (silene virginica), we show how the ... | 2008 | 18662121 |
| mating system of the anther smut fungus microbotryum violaceum: selfing under heterothallism. | | 2008 | 18281603 |
| phylogenetic evidence of host-specific cryptic species in the anther smut fungus. | cryptic structure of species complexes confounds an accurate accounting of biological diversity in natural systems. also, cryptic sibling species often become specialized to different ecological conditions, for instance, with host specialization by cryptic parasite species. the fungus microbotryum violaceum causes anther smut disease in plants of caryophyllaceae, and the degree of specialization and gene flow between strains on different hosts have been controversial in the literature. we conduc ... | 2007 | 17300424 |
| pathogen relatedness affects the prevalence of within-host competition. | although the evolutionary consequences of within-host competition among pathogens have been examined extensively, there exists a critical gap in our understanding of factors determining the prevalence of multiple infections. here we examine the effects of relatedness among strains of the anther-smut pathogen microbotryum violaceum on the probability of multiple infection in its host, silene latifolia, after sequential inoculations. we found a significantly higher probability of multiple infectio ... | 2006 | 16874619 |
| tithoniamarin and tithoniamide: a structurally unique isocoumarin dimer and a new ceramide from tithonia diversifolia. | tithoniamarin (1), a new isocoumarin dimer and a new ceramide, named tithoniamide (2a), have been isolated from tithonia diversifolia, in addition to the known beta-sitosterol and beta-sitosterol glucopyranoside. the structures were elucidated on the basis of spectroscopic and chemical evidence. preliminary studies showed that 1 has antifungal and herbicidal activities against microbotryum violaceum and chlorella fusca. | 2006 | 16753922 |
| common sex-linked deleterious alleles in a plant parasitic fungus alter infection success but show no pleiotropic advantage. | microbotryum violaceum is a fungus that causes the sterilizing anther smut disease in caryophyllaceae. its diploid teliospores normally produce equal proportions of haploid sporidia of its two mating types. however natural populations contain high frequencies of individuals producing sporidia of only one mating type ('biased strains'). this mating type-ratio bias is caused by deleterious alleles at haploid phase ('haplo-lethals') linked to the mating type locus that can be transmitted only by in ... | 2006 | 16674592 |
| male-fertility genes expressed in male flower buds of silene latifolia include homologs of anther-specific genes. | when the female plant of silene latifolia is infected with the smut fungus microbotryum violaceum, its rudimentary stamens develop into anthers which contain fungus teliospores instead of pollen. to identify genes required for maturation of anthers in s. latifolia, we performed a cdna subtraction approach with healthy male buds and female buds infected with m. violaceum. we isolated five cdna clones, which were preferentially expressed in healthy male buds during stages associated with a burst i ... | 2005 | 16501309 |
| seed fitness of hermaphrodites in areas with females and anther smut disease: silene acaulis and microbotryum violaceum. | sex-dependent infection rates could change the effective sex ratio of a population. here, i tested whether females and hermaphrodites of silene acaulis were equally likely to be infected by microbotryum violaceum, a fungus that sterilizes the host, and whether sex allocation in hermaphrodites differed between low and high disease plots. sex ratios of healthy and diseased plants were estimated in five natural plots. fitness gained through seed production was estimated by measuring seed quantity a ... | 2006 | 16441755 |
| natural selection on floral traits of female silene dioica by a sexually transmitted disease. | floral traits endowing high reproductive fitness can also affect the probability of plants contracting sexually transmitted diseases. we explore how variations in floral traits influence the fitness of silene dioica females in their interactions with pollinators carrying pollen or spores of the sterilizing anther-smut fungus microbotryum violaceum. we collected healthy and infected plants in a highly diseased population and grew them under conditions that 'cure' infected individuals, and used st ... | 2006 | 16441754 |
| coping with third parties in a nursery pollination mutualism: hadena bicruris avoids oviposition on pathogen-infected, less rewarding silene latifolia. | in nursery pollination systems, pollinator offspring usually feed on pollinated fruits or seeds. costs and benefits of the interaction for plant and pollinator, and hence its local outcome (antagonism-mutualism), can be affected by the presence of 'third-party' species. infection of silene latifolia plants by the fungus microbotryum violaceum halts the development of fruits that provide shelter and food for larvae of the pollinating moth hadena bicruris. we investigated whether the moth secures ... | 2006 | 16441753 |
| ultrastructural analysis of the behavior of the dimorphic fungus microbotryum violaceum in fungus-induced anthers of female silene latifolia flowers. | the development of male organs is induced in female flowers of the dioecious plant silene latifolia by infection with the fungus microbotryum violaceum. stamens in a healthy female flower grow only to stage 6, whereas those in an infected female flower develop to the mature stage (stage 12), at which the stamens are filled with fungal teliospores instead of pollen grains. to investigate these host-parasite interactions, young floral buds and fungus-induced anthers of infected female flowers were ... | 2005 | 16333578 |
| the anther smut disease on gypsophila repens: a case of parasite sub-optimal performance following a recent host shift? | the study of how parasites adapt to new hosts is of great importance for understanding the emergence of new diseases. here, we report a study of the anther smut disease on gypsophila repens (caryophyllaceae). in contrast to what is usually found on other host species, infected natural populations of g. repens are extremely rare. moreover, symptoms of diseased plants are incomplete and highly variable over the time. these results suggest that the fungus infecting g. repens is a case of a parasite ... | 2005 | 16135124 |
| repetitive dna in the automictic fungus microbotryum violaceum. | the small genomes of fungi are expected to have little repetitive content other than rdna genes. moreover, among asexual or highly selfing lineages, the diversity of repetitive elements is also expected to be very low. however, in the automictic fungus microbotryum violaceum, a very large proportion of random dna fragments from the autosomes and the fungal sex chromosomes are repetitive in nature, either as retrotransposon or helicase sequences. among the retrotransposon sequences, examples were ... | 2005 | 16010998 |
| repeat-induced point mutation and the population structure of transposable elements in microbotryum violaceum. | repeat-induced point mutation (rip) is a genome defense in fungi that hypermutates repetitive dna and is suggested to limit the accumulation of transposable elements. the genome of microbotryum violaceum has a high density of transposable elements compared to other fungi, but there is also evidence of rip activity. this is the first report of rip in a basidiomycete and was obtained by sequencing multiple copies of the integrase gene of a copia-type transposable element and the helicase gene of a ... | 2005 | 15911572 |
| host-related genetic differentiation in the anther smut fungus microbotryum violaceum in sympatric, parapatric and allopatric populations of two host species silene latifolia and s. dioica. | we investigated genetic diversity in west european populations of the fungal pathogen microbotryum violaceum in sympatric, parapatric and allopatric populations of the host species silene latifolia and s. dioica, using four polymorphic microsatellite loci. in allopatric host populations, the fungus was highly differentiated by host species, exhibiting high values of f(st) and r(st), and revealed clear and distinct host races. in sympatric and parapatric populations we found significant populatio ... | 2005 | 15669977 |
| shared forces of sex chromosome evolution in haploid-mating and diploid-mating organisms: microbotryum violaceum and other model organisms. | it is usually posited that the most important factors contributing to sex chromosome evolution in diploids are the suppression of meiotic recombination and the asymmetry that results from one chromosome (the y) being permanently heterozygous and the other (the x) being homozygous in half of the individuals involved in mating. to distinguish between the roles of these two factors, it would be valuable to compare sex chromosomes in diploid-mating organisms and organisms where mating compatibility ... | 2004 | 15454533 |
| patterns of within population dispersal and mating of the fungus microbotryum violaceum parasitising the plant silene latifolia. | this study explores the patterns of dispersal and mating of the anther smut microbotryum violaceum, a model species in genetics and evolutionary biology. a french metapopulation of the fungus collected from its caryophyllaceous host silene latifolia was analysed using microsatellites. the genetic diversity was low, populations were strongly differentiated, and there was no pattern of isolation by distance among populations. there was a strong deficit in heterozygotes, confirming the high self-fe ... | 2004 | 15292913 |
| plant species descriptions show signs of disease. | it is well known that diseases can greatly influence the morphology of plants, but often the incidence of disease is either too rare or the symptoms too obvious for the 'abnormalities' to cause confusion in systematics. however, we have recently come across several misinterpretations of disease-induced traits that may have been perpetuated into modern species inventories. anther-smut disease (caused by the fungus microbotryum violaceum) is common in many members of the caryophyllaceae and relate ... | 2003 | 14667368 |
| dna polymorphism in recombining and non-recombing mating-type-specific loci of the smut fungus microbotryum. | the population-genetic processes leading to the genetic degeneration of non-recombining regions have mainly been studied in animal and plant sex chromosomes. here, we report population genetic analysis of the processes in the non-recombining mating-type-specific regions of the smut fungus microbotryum violaceum. m. violaceum has a1 and a2 mating types, determined by mating-type-specific 'sex chromosomes' that contain 1-2 mb long non-recombining regions. if genetic degeneration were occurring, th ... | 2010 | 21081967 |
| using phylogenies of pheromone receptor genes in the microbotryum violaceum species complex to investigate possible speciation by hybridization. | several cases of speciation by hybridization have been reported in fungi, mostly involving recent hybridization between closely related species. in the basidiomycete genus microbotryum by contrast some species were suspected to have arisen by hybridization between moderately distant species. in particular two species, m. lagerheimii and m. silenes-acaulis, had different placements in phylogenetic trees depending on the genes considered. microbotryum species exhibit bipolar heterothallism, and he ... | 2010 | 20524600 |
| the impact of genome defense on mobile elements in microbotryum. | repeat induced point mutation (rip), a mechanism causing hypermutation of repetitive dna sequences in fungi, has been described as a 'genome defense' which functions to inactivate mobile elements and inhibit their deleterious effects on genome stability. here we address the interactions between rip and transposable elements in the microbotryum violaceum species complex. ten strains of m. violaceum, most of which belong to different species of the fungus, were all found to contain intragenomic po ... | 2010 | 19898943 |
| evolutionary strata in a small mating-type-specific region of the smut fungus microbotryum violaceum. | dna sequence analysis and genetic mapping of loci from mating-type-specific chromosomes of the smut fungus microbotryum violaceum demonstrated that the nonrecombining mating-type-specific region in this species comprises approximately 25% ( approximately 1 mb) of the chromosome length. divergence between homologous mating-type-linked genes in this region varies between 0 and 8.6%, resembling the evolutionary strata of vertebrate and plant sex chromosomes. | 2009 | 19448270 |
| antifungal metabolites from fungal endophytes of pinus strobus. | the extracts of five foliar fungal endophytes isolated from pinus strobus (eastern white pine) that showed antifungal activity in disc diffusion assays were selected for further study. from these strains, the aliphatic polyketide compound 1 and three related sesquiterpenes 2-4 were isolated and characterized. compound 2 is reported for the first time as a natural product and the e/z conformational isomers 3 and 4 were hitherto unknown. additionally, the three known macrolides; pyrenophorol (5), ... | 2011 | 21632082 |
| herbarium studies on the distribution of anther-smut fungus (microbotryum violaceum) and silene species (caryophyllaceae) in the eastern united states. | we used herbarium specimens of silene virginica, s. caroliniana, s. rotundifolia, and s. latifolia to survey the incidence of anther-smut disease (caused by microbotryum violaceum sensu lato) in the eastern usa. we found no evidence of a collector bias against diseased specimens. diseased specimens were frequently found in collections of s. virginica and s. caroliniana, but not in those of s. rotundifolia or s. latifolia. disease incidence in s. virginica and s. caroliniana increased significant ... | 2003 | 21659105 |
| sex-specific effect of microbotryum violaceum (uredinales) spores on healthy plants of the gynodioecious gypsophila repens (caryophyllaceae). | females of gynodioecious species need to have reproductive advantages to compensate for their lack of male function and assure their maintenance in natural populations. females may be more fecund than hermaphrodites because they reallocate resources from male to female function, avoid selfing and inbreeding depression, or produce higher quality offspring by screening arriving pollen better. a novel type of female advantage is proposed that may be important for several species of gynodioecious ca ... | 2005 | 21652472 |