Publications (60) View all
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Article: Comparison of ectomycorrhizal communities in natural and cultivated Tuber melanosporum truffle grounds.
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ABSTRACT: Truffles are hypogeous ectomycorrhizal (EM) fungi belonging to the genus Tuber. Although outplanting of truffle-inoculated host plants has enabled the realization of productive orchards, truffle cultivation is not yet standardized. Therefore, monitoring the distribution of fungal species in different truffle fields may help us to elucidate the factors that shape microbial communities and influence the propagation and fruiting of Tuber spp. In this study, we compared the fungal biodiversity in cultivated and natural Tuber melanosporum truffle fields located in Central Italy. To this end, ectomycorrhizas (ECM) and soil samples were molecularly analyzed, and an inventory of the fungi associated with Quercus pubescens plants colonized by T. melanosporum, Tuber aestivum or Tuber brumale was compiled. T. melanosporum and T. aestivum were dominant on the cultivated plants, and the number of EM species was markedly lower in the cultivated sites than in the natural sites. However, in the same site, EM biodiversity was higher in T. brumale-colonized plants than in T. melanosporum-colonized plants. These results suggest that different Tuber spp. may have different competitive effects on the other mycobionts. Additionally, in keeping with our previous findings, we found that the number of T. melanosporum genotypes recovered from the soil samples was higher than that of the underlying ECM.FEMS Microbiology Ecology 04/2012; 81(3):547-61. · 3.41 Impact Factor -
Article: Distribution and localization of microsatellites in the Perigord black truffle genome and identification of new molecular markers.
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ABSTRACT: The level of genetic diversity and genetic structure in the Perigord black truffle (Tuber melanosporum Vittad.) has been debated for several years, mainly due to the lack of appropriate genetic markers. Microsatellites or simple sequence repeats (SSRs) are important for the genome organisation, phenotypic diversity and are one of the most popular molecular markers. In this study, we surveyed the T. melanosporum genome (1) to characterise its SSR pattern; (2) to compare it with SSR patterns found in 48 other fungal and three oomycetes genomes and (3) to identify new polymorphic SSR markers for population genetics. The T. melanosporum genome is rich in SSRs with 22,425 SSRs with mono-nucleotides being the most frequent motifs. SSRs were found in all genomic regions although they are more frequent in non-coding regions (introns and intergenic regions). Sixty out of 135 PCR-amplified mono-, di-, tri-, tetra, penta, and hexa-nucleotides were polymorphic (44%) within black truffle populations and 27 were randomly selected and analysed on 139 T. melanosporum isolates from France, Italy and Spain. The number of alleles varied from 2 to 18 and the expected heterozygosity from 0.124 to 0.815. One hundred and thirty-two different multilocus genotypes out of the 139 T. melanosporum isolates were identified and the genotypic diversity was high (0.999). Polymorphic SSRs were found in UTR regulatory regions of fruiting bodies and ectomycorrhiza regulated genes, suggesting that they may play a role in phenotypic variation. In conclusion, SSRs developed in this study were highly polymorphic and our results showed that T. melanosporum is a species with an important genetic diversity, which is in agreement with its recently uncovered heterothallic mating system.Fungal Genetics and Biology 10/2010; 48(6):592-601. · 3.74 Impact Factor -
Article: Isolation and characterization of polymorphic microsatellite loci in white truffle (Tuber magnatum)
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ABSTRACT: Tuber spp. are fungi that establish symbiosis with several trees and shrubs. Some of these fungal species produce edible ascomata, also known as truffles, which are highly appreciated for their taste and odour. We isolated and characterized eight polymorphic microsatellite loci from Tuber magnatum, the finest white truffle species, and assessed their variability in 370 individuals collected from all over the species range of distribution. Although two to 18 alleles per locus were found, no heterozygous individuals were observed. The availability of simple sequence repeat loci provides valuable tools for assessment of the genetic structure and population dynamics in this species.Molecular Ecology Notes 02/2004; 4(1):116 - 118. · 2.38 Impact Factor -
Article: Expression patterns of endothelial and inducible nitric oxide synthase isoforms in corpora lutea of pseudopregnant rabbits at different luteal stages.
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ABSTRACT: Total activity of nitric oxide (NO) synthase (NOS) and expression of both endothelial (eNOS) and inducible (iNOS) isoforms were examined in corpora lutea (CL) of rabbits across pseudopregnancy by quantitative RT-PCR analysis, Western blot and immunohistochemistry. CL were collected at early- (day 4), mid- (day 9) and late- (day 13) luteal phases of pseudopregnancy. The PCR product of rabbit luteal eNOS was cloned and its direct sequence exhibited 90% homology with those of other species. The steady-state mRNA levels encoding eNOS remained fairly constant throughout both early- and mid-luteal stages of pseudopregnancy but dropped almost to half (P</=0.05) by day 13. By contrast, luteal eNOS proteins increased 2-fold (P</=0.05) from the early- to late-luteal phase. Independently of CL age, iNOS mRNA was very poorly expressed while protein levels gradually declined from the early- to late-luteal stage. Intense eNOS-like immunoreactivity was detected in large luteal cells, while iNOS staining was targeted to a few, isolated cells, probably macrophages. Basal NOS activity was greater in day 4 CL than in both day 9 and day 13 CL. These data are the first to characterize in rabbit CL the temporal expression patterns of NOS isoforms across different luteal stages of pseudopregnancy and, collectively, suggest the existence of an expressional control for this constitutive isoform, which might have a physiological role in regulating CL function during development.Journal of Endocrinology 06/2002; 173(2):285-96. · 3.55 Impact Factor -
Article: The volatile organic compounds from the mycelium of Tuber borchii Vitt.
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ABSTRACT: The mycelium of T. borchii (characterized by DNA analysis) grown in sterile liquid medium produced some VOCs. The VOCs were retained on carbographs by passing a flow of helium, isolated and characterized in a GC-MS equipment after a thermal desorption. The compounds present in the VOCs from the mycelium cultures, but not in the VOCs from the control cultures, contained 29 compounds. The main compounds were 1,3-ditertbutylbenzene (16.1 ng/l), 3-methylheptane (9.2 ng/l), butan-2-one (8.8 ng/l), ethynylbenzene (5.6 ng/l), and octan-3-one (4.9 ng/l).Phytochemistry 01/2001; 55(8):983-5. · 3.35 Impact Factor
