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In this paper, we demonstrate the ability of Arabidopsis thaliana to detect different mixtures of volatile organic compounds (VOCs) emitted by the common indoor fungus, Aspergillus versicolor, and demonstrate the potential usage of the plant as a bioindicator to monitor fungal VOCs in indoor air. We evaluated the volatile production of Aspergillus versicolor strains SRRC 108 (NRRL 3449) and SRRC 2559 (ATCC 32662) grown on nutrient rich fungal medium, and grown under conditions to mimic the substrate encountered in the built environment where fungi would typically grow indoors (moist wallboard and ceiling tiles). Using headspace solid phase microextraction/gas chromatography-mass spectrometry, we analyzed VOC profiles of the two strains. The most abundant compound produced by both strains on all three media was 1-octen-3-ol. Strain SRRC 2559 made several terpenes not detected from strain SRRC 108. Using a split-plate bioassay, we grew Arabidopsis thaliana in a shared atmosphere with VOCs from the two strains of Aspergillus versicolor grown on yeast extract sucrose medium. The VOCs emitted by SRRC 2559 had an adverse impact on seed germination and plant growth. Chemical standards of individual VOCs from the Aspergillus versicolor mixture (2-methyl-1-butanol, 3-methyl-1-butanol, 1-octen-3-ol, limonene, and β-farnesene), and β-caryophyllene were tested one by one in seed germination and vegetative plant growth assays. The most inhibitory compound to both seed germination and plant growth was 1-octen-3-ol. Our data suggest that Arabidopsis is a useful model for monitoring indoor air quality as it is sensitive to naturally emitted fungal volatile mixtures as well as to chemical standards of individual compounds, and it exhibits relatively quick concentration- and duration-dependent responses.

Summary The domestication of animals, plants, and microbes fundamentally transformed the lifestyle and demography of the human species [1]. Although the genetic and functional underpinnings of animal and plant domestication are well understood, little is known about microbe domestication [2–6]. Here, we systematically examined genome-wide sequence and functional variation between the domesticated fungus Aspergillus oryzae , whose saccharification abilities humans have harnessed for thousands of years to produce sake, soy sauce, and miso from starch-rich grains, and its wild relative A. flavus , a potentially toxigenic plant and animal pathogen [7]. We discovered dramatic changes in the sequence variation and abundance profiles of genes and wholesale primary and secondary metabolic pathways between domesticated and wild relative isolates during growth on rice. Our data suggest that, through selection by humans, an atoxigenic lineage of A. flavus gradually evolved into a "cell factory" for enzymes and metabolites involved in the saccharification process. These results suggest that whereas animal and plant domestication was largely driven by Neolithic "genetic tinkering" of developmental pathways, microbe domestication was driven by extensive remodeling of metabolism.

Production of carcinogenic aflatoxins has been reported from members of Aspergillus section Flavi, Aspergillus section Nidulantes and a newly proposed Aspergillus section Ochraceorosei that consists of Aspergillus ochraceoroseus and A. rambellii. Unlike members of section Flavi, A. ochraceoroseus and A. rambellii have been shown to accumulate both aflatoxin (AF) and the aflatoxin precursor sterigmatocystin (ST). Alhough morphologically distinct from A. nidulans, molecular characterization of A. ochraceoroseus AF/ST genes and physiological characteristics of AF/ST production indicated that A. ochraceoroseus is more closely related to A. nidulans than to A. flavus. Knowing that the A. nidulans ST gene cluster is organized differently from the A. flavus AF gene cluster, we determined the genetic organization of the AF/ST biosynthetic cluster in A. ochraceoroseus. Sequencing of overlapping lambda clones and genomic PCR fragments obtained by gene-walking techniques demonstrated that the A. ochraceoroseus AF/ST gene cluster is organized much like the A. nidulans ST gene cluster except that the region from aflN to aflW is located directly upstream of aflC and in reverse orientation such that aflW represents the distal end and aflY the proximal end of the cluster. The A. ochraceoroseus cluster genes demonstrated 62-76% nucleotide identity to their A. nidulans ST cluster gene homologs. Transformation of an A. nidulans aflR mutant with the A. ochraceoroseus aflR restored ST production in A. nidulans transformants. PCR amplification of A. rambellii genomic DNA demonstrated that the AF/ST gene cluster is organized in the same manner as that of A. ochraceoroseus.

As the number of cases of aspergillosis grows, the number of species reported to cause the disease is increasing. Historically, classification and identification of aspergilli was accomplished using morphological characteristics. A number of molecular, immunological and biochemical methods are now available. For the most part, the results of the various approaches concur, yielding similar results in identifying aspergilli, so the 'best' method for identification is the method that best suits the needs of the researcher or clinician. Each identification method has advantages and disadvantages which will be discussed herein. The paper contains a listing of some of the available identification systems from those that address the whole genus to those capable of separating intraspecific strains.

Most aspergilli that produce aflatoxin are members of Aspergillus section Flavi, however isolates of several Aspergillus species not closely related to section Flavi also have been found to produce aflatoxin. Two of the species, Aspergillus ochraceoroseus and an undescribed Aspergillus species SRRC 1468, are morphologically similar to members of Aspergillus section Circumdati. The other species have Emericella teleomorphs (Em. astellata and an undescribed Emericella species SRRC 2520) and are morphologically distinctive in having ascospores with large flanges. All these aflatoxin-producing isolates were from tropical zones near oceans, and none of them grew on artificial media at 37 C. Aflatoxins and sterigmatocystin production were quantified by high-pressure liquid chromatography (HPLC) and confirmed by HPLC-mass spectrometry (LC-MS) detection. Phylogenetic analyses were conducted on these four species using A. parasiticus and Em. nidulans, (which produce aflatoxin and the aflatoxin precursor sterigmatocystin, respectively) for comparison. Two aflatoxin/sterigmatocystin biosynthesis genes and the beta tubulin gene were used in the analyses. Results showed that of the new aflatoxin-producers, Aspergillus SRRC 1468 forms a strongly supported clade with A. ochraceoroseus as does Emericella SRRC 2520 with Em. astellata SRRC 503 and 512.

Based on counts of Aspergillus species reported in over 250 studies of microfungi from soils and litter, chi-square analyses were conducted on species occurrence in five biomes and five latitude ranges to determine variations from expected distributions. There was no overall trend in distribution of the members of the entire genus by biome, however, individual sections of the genus appeared to have distinct distribution patterns. Most members of sections Aspergillus, Nidulantes, Flavipedes and Circumdati occurred at greater than expected frequencies in desert soils. There was no distinct pattern of species occurrence for forest, wetland, or cultivated soils, although members of section Nidulantes were quite rare in cultivated soils. Most species occurred at or below expected frequencies in grassland soils. Members of the genus tended to occur at greater than expected frequencies at latitudes in the subtropical/warm temperate zone between 26 and 35 degrees. Most species occurred at expected frequencies in the lower latitudes, and below expected frequencies in latitudes greater than 35 degrees.

Twenty-four species placed in Aspergillus section Versicolores were examined for macromorphological and micromorphological characteristics. Based on these characters, an identification key to the species was created. A cluster analysis of the data indicated that five of the species, A. silvaticus, A. speluneus, A. floriformis, A. pseudodeflectus, and A. pulvinus were only weakly aligned with other members of the section.

Based on counts of Aspergillus species reported in over 250 studies of microfungi from soils and litter, chi-square analyses were conducted on species occurrence in five biomes and five latitude ranges to determine variations from expected distributions. There was no overall trend in distribution of the members of the entire genus by biome, however, individual sections of the genus appeared to have distinct distribution patterns. Most members of sections Aspergillus, Nidulantes, Flavipedes and Circumdati occurred at greater than expected frequencies in desert soils. There was no distinct pattern of species occurrence for forest, wetland, or cultivated soils, although members of section Nidulantes were quite rare in cultivated soils. Most species occurred at or below expected frequencies in grassland soils. Members of the genus tended to occur at greater than expected frequencies at latitudes in the subtropical/warm temperate zone between 26 and 35 degrees. Most species occurred at expected frequencies in the lower latitudes, and below expected frequencies in latitudes greater than 35 degrees.

Aspergillus ochraceoroseus produces the yellow-gold conidia and other characteristics of Aspergillus subgenus Circumdati section Circumdati. However, this species produces aflatoxin, a secondary metabolite characteristic of some members of subgenus Circumdati section Flavi and sterigmatocystin, a related secondary metabolite usually associated with subgenus Nidulantes sections Nidulantes and Versicolores, as well as members of several other genera. Our morphological data support the placement of A. ochraceoroseus in subgenus Circumdati. Sequence data from A. ochraceoroseus aflatoxin and sterigmatocystin genes aflR and nor-1/stcE, as well as 5.8S ITS and beta tubulin genes, were compared to those of aspergilli in sections Circumdati, Flavi, Nidulantes and Versicolores. In the sequence comparisons, A. ochraceoroseus was related more closely to the species in subgenus Nidulantes than to species from subgenus Circumdati.

SUMMARY Aspergillus flavus is an opportunistic pathogen of crops. It is important because it produces aflatoxin as a secondary metabolite in the seeds of a number of crops both before and after harvest. Aflatoxin is a potent carcinogen that is highly regulated in most countries. In the field, aflatoxin is associated with drought-stressed oilseed crops including maize, peanut, cottonseed and tree nuts. Under the right conditions, the fungus will grow and produce aflatoxin in almost any stored crop seed. In storage, aflatoxin can be controlled by maintaining available moisture at levels below that which will support growth of A. flavus. A number of field control measures are being utilized or explored, including: modification of cultural practices; development of resistant crops through molecular and proteomic techniques; competitive exclusion using strains that do not produce aflatoxin; and development of field treatments that would block aflatoxin production. Taxonomy: Aspergillus flavus Link (teleomorph unknown) kingdom Fungi, phyllum Ascomycota, order Eurotiales, class Eurotiomycetes, family Trichocomaceae, genus Aspergillus, species flavus. Host range: Aspergillus flavus has a broad host range as an opportunistic pathogen/saprobe. It is an extremely common soil fungus. The major concern with this fungus in agriculture is that it produces highly carcinogenic toxins called aflatoxins which are a health hazard to animals. In the field, A. flavus is predominantly a problem in the oilseed crops maize, peanuts, cottonseed and tree nuts. Under improper storage conditions, A. flavus is capable of growing and forming aflatoxin in almost any crop seed. It also is a pathogen of animals and insects. In humans it is predominantly an opportunistic pathogen of immunosuppressed patients. Useful websites: http://www.aspergillusflavus.org, http://www.aflatoxin.info/health.asp, plantpathology.tamu.edu/aflatoxin, http://www.aspergillus.org.uk

5 pages; International audience; This article documents the addition of 411 microsatellite marker loci and 15 pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Acanthopagrus schlegeli, Anopheles lesteri, Aspergillus clavatus, Aspergillus flavus, Aspergillus fumigatus, Aspergillus oryzae, Aspergillus terreus, Branchiostoma japonicum, Branchiostoma belcheri, Colias behrii, Coryphopterus personatus, Cynogolssus semilaevis, Cynoglossus semilaevis, Dendrobium officinale, Dendrobium officinale, Dysoxylum malabaricum, Metrioptera roeselii, Myrmeciza exsul, Ochotona thibetana, Neosartorya fischeri, Nothofagus pumilio, Onychodactylus fischeri, Phoenicopterus roseus, Salvia officinalis L., Scylla paramamosain, Silene latifo, Sula sula, and Vulpes vulpes. These loci were cross-tested on the following species: Aspergillus giganteus, Colias pelidne, Colias interior, Colias meadii, Colias eurytheme, Coryphopterus lipernes, Coryphopterus glaucofrenum, Coryphopterus eidolon, Gnatholepis thompsoni, Elacatinus evelynae, Dendrobium loddigesii Dendrobium devonianum, Dysoxylum binectariferum, Nothofagus antarctica, Nothofagus dombeyii, Nothofagus nervosa, Nothofagus obliqua, Sula nebouxii, and Sula variegata. This article also documents the addition of 39 sequencing primer pairs and 15 allele specific primers or probes for Paralithodes camtschaticus.

There is a large and rapidly growing market for fresh-cut fruit. Microbial volatile organic compounds indicate the presence of fungal or bacterial contamination in fruit. In order to determine whether microbial volatile organic compounds can be used to detect contamination before fruit becomes unmarketable, pieces of cantaloupe, apple, pineapple, and orange were inoculated with a variety of fungal species, incubated at 25 degrees C, then sealed in glass vials. The volatiles were extracted by headspace solid-phase microextraction and analyzed by gas chromatography-mass spectrometry. Forty-five compounds were identified that might serve as unique identifiers of fungal contamination. Fungal contamination can be detected as early as 24 h after inoculation.

In greenhouse and field studies, cotton ( Gossypium hirsutum L.) flowers were inoculated with Aspergillus flavus at the involucral nectaries. Bolls developing from early-season flowers had significantly higher percentages of A. flavus -infected seed than did bolls from flowers formed later in the season. Seeds from bolls inoculated 2 weeks after anthesis had the same infection levels as those from flowers inoculated at anthesis. These results indicate that early-season flowers are predisposed to A. flavus infection and that the degree of susceptibility at anthesis is retained through early boll development.

Cotton dust associated with high pulmonary function decrements contains relatively high levels of mannitol. In this study, cotton leaf and bract tissue and dust isolated from cotton leaf tissue were examined by optical microscopy, scanning electron microscopy, and capillary gas chromatography. Alternaria alternata, Cladosporium herbarum, Epicoccum purpurascens , and Fusarium pallidoroseum were isolated from cotton leaf dust. The fungal samples, cotton dust, and cotton leaf contained mannitol. This study demonstrates that fungi from a late-fall harvest of cotton leaf material produce mannitol and are a probable source of the mannitol found in cotton dust.

Delinted, surface-sterilized cotton seeds from Regional Cotton Variety Test locations in the southern USA were assessed for presence of filamentous fungi. There were no consistent differences in fungal flora among the cultivars examined. Of the thirty-seven taxa isolated, only Alternaria spp., Colletotrichum gossypii, Fusarium equiseti, and F. pallidoroseum (F. semitectum) were present in more than 10% of the seed at any sampling location in a given year. Infection levels varied greatly between locations and in different years within a location. Changes in infection levels for some of the species were attributable to precipitation and temperature variations during the growing season.

Fusarium semitectum Berkeley and Ravenel and other nonpathogenic fungi appear to contaminate immature cottonseed but cannot express themselves until immediately after seed maturation. It is hypothesized that catechin prevents fungal outgrowth and that inhibition is released when catechin is polymerized during seed maturation.

Aspergillus flavus was introduced into several natural openings in cotton plants at or before anthesis and the subsequent infection rate in the mature seed determined. Cotyledonary leaf scars of seedlings, unopened flower buds, and involucral nectaries or stigmata of newly opened flowers were inoculated with dry fungal spores. Seeds from plants inoculated at the cotyledonary node, involucral nectaries, and flower buds had significantly higher A. flavus infection rates than uninoculated control plants.

Cotton flowers in replicate plots in two fields near Phoenix, Ariz., were tagged in June at the beginning of the flowering period. Flowers or developing bolls from these tagged flowers were inoculated on the involucral (bracteal) nectaries with dry spores of Aspergillus flavus. The bolls were harvested as they matured in August, and the seeds were assessed for the presence of the fungus. The number of infected seed from flowers and bolls inoculated up to 25 days after anthesis was significantly higher than that in uninoculated controls. Seeds from bolls inoculated after 25 days postanthesis did not differ significantly from controls in degree of infection. We postulate that the sharp decline in the ability of the fungus to infect the plant and seed is a result of physical or biochemical changes in the boll as it reaches physiological maturity or biochemical changes in the entire plant as it develops.

(1989). Use of a Bleomycin-Containing Medium to Distinguish Aspergillus Parasiticus from A. Sojae. Mycologia: Vol. 81, No. 1, pp. 159-160.

Thousands of fungal species are classified as hyphomycetes. Many of these species have a significant impact on moder society as pathogens, both plant and animal, as producers ofmycotoxins, as food spoilage and fermentation organisms, and as potential candidates for manipulation in the biotechnological industries. However, with few exceptions, i.e., Aspergillus nidulans and the anamorph of Neurospora crassa, little genetic information is available on the majority of filamentous fungi. Several developmentally regulated genes have been cloned from A. nidulans including SpoCI (Timberlake and Barnard, 1981; Gwynne et al., 1984) and tubC (May et al., 1985). SpoCI is a gene cluster that codes for several poly(A) + RNAs that are preferentially expressed during conidiophore development. Beta3-tubulin (tubC) functions in the development of microtubules during conidial mitosis and is either absent or found in only trace levels in the vegetative state. The non-developmentally regulated (i.e., is present in vegetative cultures) benA gene codes for two other beta-tubulin polypeptides, betal and beta2, in A. nidulans. Except for a survey of representatives of the genus Aspergillus (Mullaney and Klich, 1987), no information exists regarding the analogous genes in other filamentous fungi. The widespread distribution of similar genes outside the aspergilli would enhance the use of A. nidulans as a model to study other fungal species. Such a model would facilitate developmental regulation studies in many economically important hyphomycetes. As an initial step in determining if other filamentous fungi have similar developmental genes to those of A. nidulans, several hyphomycetes