Tuber spp. are ascomycetes that grow in ectomycorrhizal symbioses with some tree and shrub specie... more Tuber spp. are ascomycetes that grow in ectomycorrhizal symbioses with some tree and shrub species and produce ascomata, known as truffles. Some truffles are edible and marketed world-wide. Tuber magnatum produces white truffles and is the most prestigious Tuber spp., harvested in Italy and in some Balkan areas only. In the present study we aimed at assessing the within- and among-populations genetic variability in T. magnatum by means of Tuber specific microsatellite markers and an extensive sampling across the species distributional range. We show, for the first time, that some white truffle populations are genetically traceable and that an extensive gene flow occurs within populations. Thus new perspectives are now open concerning the studies aimed at shedding light on Tuber spp. reproductive systems; our results suggest that molecular markers could be successfully used to characterize and trace white truffles according to their geographic provenance. The consequences of our find...
The invention concerns a method for determining the Tuber species and fertility of a truffle samp... more The invention concerns a method for determining the Tuber species and fertility of a truffle sample, said method comprising: - identifying whether said truffle sample comprises a first nucleotide sequence associated with a first mating type idiomorph (MAT1-2); and - identifying whether said truffle sample comprises a second nucleotide sequence associated with a second mating type idiomorph (MAT1-1); the fertility of said truffle sample requiring the presence of both the first and the second nucleotide sequences
The Boletus edulis species complex includes ectomycorrhizal fungi producing edible mushrooms appr... more The Boletus edulis species complex includes ectomycorrhizal fungi producing edible mushrooms appreciated worldwide. However, species delineation is very difficult in these fungi, because it is based exclusively on a few, highly variable morphological features. As a consequence, a high number of taxa--including several varieties, subspecies and/or species sensu stricto--have been described in this species complex. In this paper we report on an extensive analysis of internal transcribed spacer of the nuclear rDNA region on a large sample of species of the B. edulis complex, mainly harvested in Italy, and representative of the European variability of this group. The molecular analysis allowed us to discriminate among and within B. edulis, B. aestivalis, B. pinophilus and B. aereus spp. and resolve their phylogenetic relationship.
ABSTRACT Tuber melanosporum Vittad. is the symbiotic ascomycete that produces the Périgord truffl... more ABSTRACT Tuber melanosporum Vittad. is the symbiotic ascomycete that produces the Périgord truffle, one of the most expensive foods worldwide. Although basic research on symbiotic ascomycetes lags behind that on symbiotic basidiomycetes, some progress has been made in the last few years on key questions concerning the biology and ecology of Tuber spp. In particular, the recent release of the T. melanosporum genome was a breakthrough that helped improve our understanding of the reproductive biology of this species. It also provided insight into the gene repertoires underlying the symbiotic relationship with host plants and the production of the distinctive truffle aroma. Genome mining has provided mycologists with a plethora of microsatellite markers that may be highly informative for population genetics studies. These recent advances in T. melanosporum research are discussed here in the context of fundamental research questions and the cultivation and marketing of truffle species.
Lotus corniculatus plants transformed with a maize cDNA (G1L) encoding a sulphur-rich γ-zein were... more Lotus corniculatus plants transformed with a maize cDNA (G1L) encoding a sulphur-rich γ-zein were obtained by using two fusion genes: one with the CaMV 35S promoter, the other with the ribulose bisphosphate carboxylase small subunit (rbcS) promoter. The highest expression of G1L mRNA was found in plants transformed with G1L under the rbcS promoter. The steady state level of G1L
A highly repeated sequence (C300) was cloned from Medicago coerulea and its organization in the M... more A highly repeated sequence (C300) was cloned from Medicago coerulea and its organization in the M. sativa-coerulea-falcata complex, M. arborea, and three somatic hybrids involving M. sativa, was investigated. Southern-blot analysis revealed a tandemly repeated array and a species-specificity of the sequence to those species belonging to the complex. Various degrees of amplification of C300 were detected among the species
... all require the presence of a cytokinin (BA or 2iP) and an auxin (NAA or IAA); L. japoni-cus ... more ... all require the presence of a cytokinin (BA or 2iP) and an auxin (NAA or IAA); L. japoni-cus (Handberg & Stougaard, 1992) and L ... The main feature of L. angustissimus that makes this species very different from the others was the absence of morphogenesis in calli induced and ...
ABSTRACT Seven widely-cultivated alfalfa varieties and three ecotypes adapted to Central Italy we... more ABSTRACT Seven widely-cultivated alfalfa varieties and three ecotypes adapted to Central Italy were used to evaluate the extent of polymorphism in that species. Twenty plants per accession were analysed with 16 RFLP probes combined with three restriction enzymes (48 probe/enzyme combination in total) and the data were used to compute the Nei's similarity index taken as a measure of inter- and intra-population RFLP variability. The varieties were, in general, more homogeneous than the ecotypes and the cultivars ‘Adriana’ and ‘Florida’ could be differentiated more easily than the others. Few accession-specific hybridizing fragments were scored and seven populations could be distinguished from the others on the basis of significant differences in the frequencies of specific fragments. The DNA of plant populations of several sizes was bulked and the ability to detect a given fragment in pooled samples was related to the fraction of plants having that fragment among the plants forming the bulk. The results are discussed with special emphasis on the practical utilization of RFLPs for varietal identification.
The mycelium of T. borchii (characterized by DNA analysis) grown in sterile liquid medium produce... more 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).
Tuber spp. are ascomycetes that grow in ectomycorrhizal symbioses with some tree and shrub specie... more Tuber spp. are ascomycetes that grow in ectomycorrhizal symbioses with some tree and shrub species and produce ascomata, known as truffles. Some truffles are edible and marketed world-wide. Tuber magnatum produces white truffles and is the most prestigious Tuber spp., harvested in Italy and in some Balkan areas only. In the present study we aimed at assessing the within- and among-populations genetic variability in T. magnatum by means of Tuber specific microsatellite markers and an extensive sampling across the species distributional range. We show, for the first time, that some white truffle populations are genetically traceable and that an extensive gene flow occurs within populations. Thus new perspectives are now open concerning the studies aimed at shedding light on Tuber spp. reproductive systems; our results suggest that molecular markers could be successfully used to characterize and trace white truffles according to their geographic provenance. The consequences of our find...
The invention concerns a method for determining the Tuber species and fertility of a truffle samp... more The invention concerns a method for determining the Tuber species and fertility of a truffle sample, said method comprising: - identifying whether said truffle sample comprises a first nucleotide sequence associated with a first mating type idiomorph (MAT1-2); and - identifying whether said truffle sample comprises a second nucleotide sequence associated with a second mating type idiomorph (MAT1-1); the fertility of said truffle sample requiring the presence of both the first and the second nucleotide sequences
The Boletus edulis species complex includes ectomycorrhizal fungi producing edible mushrooms appr... more The Boletus edulis species complex includes ectomycorrhizal fungi producing edible mushrooms appreciated worldwide. However, species delineation is very difficult in these fungi, because it is based exclusively on a few, highly variable morphological features. As a consequence, a high number of taxa--including several varieties, subspecies and/or species sensu stricto--have been described in this species complex. In this paper we report on an extensive analysis of internal transcribed spacer of the nuclear rDNA region on a large sample of species of the B. edulis complex, mainly harvested in Italy, and representative of the European variability of this group. The molecular analysis allowed us to discriminate among and within B. edulis, B. aestivalis, B. pinophilus and B. aereus spp. and resolve their phylogenetic relationship.
ABSTRACT Tuber melanosporum Vittad. is the symbiotic ascomycete that produces the Périgord truffl... more ABSTRACT Tuber melanosporum Vittad. is the symbiotic ascomycete that produces the Périgord truffle, one of the most expensive foods worldwide. Although basic research on symbiotic ascomycetes lags behind that on symbiotic basidiomycetes, some progress has been made in the last few years on key questions concerning the biology and ecology of Tuber spp. In particular, the recent release of the T. melanosporum genome was a breakthrough that helped improve our understanding of the reproductive biology of this species. It also provided insight into the gene repertoires underlying the symbiotic relationship with host plants and the production of the distinctive truffle aroma. Genome mining has provided mycologists with a plethora of microsatellite markers that may be highly informative for population genetics studies. These recent advances in T. melanosporum research are discussed here in the context of fundamental research questions and the cultivation and marketing of truffle species.
Lotus corniculatus plants transformed with a maize cDNA (G1L) encoding a sulphur-rich γ-zein were... more Lotus corniculatus plants transformed with a maize cDNA (G1L) encoding a sulphur-rich γ-zein were obtained by using two fusion genes: one with the CaMV 35S promoter, the other with the ribulose bisphosphate carboxylase small subunit (rbcS) promoter. The highest expression of G1L mRNA was found in plants transformed with G1L under the rbcS promoter. The steady state level of G1L
A highly repeated sequence (C300) was cloned from Medicago coerulea and its organization in the M... more A highly repeated sequence (C300) was cloned from Medicago coerulea and its organization in the M. sativa-coerulea-falcata complex, M. arborea, and three somatic hybrids involving M. sativa, was investigated. Southern-blot analysis revealed a tandemly repeated array and a species-specificity of the sequence to those species belonging to the complex. Various degrees of amplification of C300 were detected among the species
... all require the presence of a cytokinin (BA or 2iP) and an auxin (NAA or IAA); L. japoni-cus ... more ... all require the presence of a cytokinin (BA or 2iP) and an auxin (NAA or IAA); L. japoni-cus (Handberg & Stougaard, 1992) and L ... The main feature of L. angustissimus that makes this species very different from the others was the absence of morphogenesis in calli induced and ...
ABSTRACT Seven widely-cultivated alfalfa varieties and three ecotypes adapted to Central Italy we... more ABSTRACT Seven widely-cultivated alfalfa varieties and three ecotypes adapted to Central Italy were used to evaluate the extent of polymorphism in that species. Twenty plants per accession were analysed with 16 RFLP probes combined with three restriction enzymes (48 probe/enzyme combination in total) and the data were used to compute the Nei's similarity index taken as a measure of inter- and intra-population RFLP variability. The varieties were, in general, more homogeneous than the ecotypes and the cultivars ‘Adriana’ and ‘Florida’ could be differentiated more easily than the others. Few accession-specific hybridizing fragments were scored and seven populations could be distinguished from the others on the basis of significant differences in the frequencies of specific fragments. The DNA of plant populations of several sizes was bulked and the ability to detect a given fragment in pooled samples was related to the fraction of plants having that fragment among the plants forming the bulk. The results are discussed with special emphasis on the practical utilization of RFLPs for varietal identification.
The mycelium of T. borchii (characterized by DNA analysis) grown in sterile liquid medium produce... more 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).
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Papers by Francesco Paolocci