In vitro interactions between Bradyrhizobium spp. and Tuber magnatum mycelium

Tuber magnatum is the most expensive truffle, but its large-scale cultivation is still a challenge compared to other valuable Tuber species. T. magnatum mycelium has never been grown profitably until now, which has led to difficulties to studying it in vitro. This study describes beneficial interactions between T. magnatum mycelium and never before described bradyrhizobia, which allows the in vitro growth of T. magnatum mycelium. Three T. magnatum strains were co-isolated on modified Woody Plant Medium (mWPM) with aerobic bacteria and characterised through microscopic observations. The difficulties of growing alone both partners, bacteria and T. magnatum mycelium, on mWPM demonstrated the reciprocal dependency. Three bacterial isolates for each T. magnatum strain were obtained and molecularly characterised by sequencing the 16S rRNA, glnII, recA and nifH genes. Phylogenetic analyses showed that all nine bacterial strains were distributed among five subclades included in a new monophyletic lineage belonging to the Bradyrhizobium genus within the Bradyrhizobium jicamae supergroup. The nifH genes were detected in all bacterial isolates, suggesting nitrogen-fixing capacities. This is the first report of consistent T. magnatum mycelium growth in vitro conditions. It has important implications for the development of new technologies in white truffle cultivation and for further studies on T. magnatum biology and genetics

The first record of Densocarpa crocea in Italy

The first record of Densocarpa crocea (Quél.) Healy & M.E. Sm in Italy is reported. The specimen was morphologically described and the ITS sequence was deposited in GenBank

The role of wild boars in spore dispersal of hypogeous fungi

Wild boars (Sus scrofa L.) are well-known for soil disturbance in natural and cultivated truffières but their role in spore dispersal is poorly investigated. In the present work we studied the occurrence of hypogeous fungal spores in faecal contents of 14 wild boars randomly hunted in “Parco dei Gessi e Calanchi dell’Abbadessa” Regional Park (North of Italy) where truffle production has been previously investigated for three years. Six methods for spore analysis in faeces were compared and the suspension of faeces in ZnSO4 (70%) solution resulted to be the most reliable. Hypogeous fungal spores, including Tuber magnatum and Tuber aestivum spores, were detected in 9 animals. This result suggests that the detection of fungal spores in faeces of wild boars may provide information on the presence of hypogeous fungi in an area. However, the poor abundance of spores suggests that the wild boar can be considered an opportunistic mycophagist, ingesting truffles only occasionally, as a seasonal source of food. Considering the magnitude of wild boar movements during seasonal migrations, it is possible to speculate that they play a key role in truffle long distance dispersal

Characterization and pathogenicity of Colletotrichum spp. causing citrus anthracnose in Tunisia

In the winter and spring of 2014–2015, typical anthracnose symptoms were detected on different citrus varieties in Cap-Bon and Morneg-Tunis regions of Northern Tunisia. Surveys were conducted to determine the casual agents of these symptoms. A total of seven monosporic isolates were obtained from dark lesions on fruits, flowers, leaves and twigs of citrus from six orchards. One Colletotrichum karstii (from the C. boninense species complex) and six C. gloeosporioides isolates were identified through morphological analysis and sequencing of their ITS rDNA sequences. Pathogenicity tests with the seven isolates were performed on symptomless, detached citrus fruits (Valencia orange and Eureka lemon). All tested isolates caused anthracnose lesions after 1 week of incubation. Koch’s postulates were fulfilled by re-isolation of pathogens from the inoculated fruits. This report elucidates the diversity of anthracnose pathogens in Tunisia. This is the first report of C. karstii from citrus in Tunisia

Tuber balkanicum – new taxon defined by molecular, ecological and biogeographical methods

Truffle diversity of Balkan Peninsula does not stop to surprise the scientific community with three new species from the melanosporum clade described in last year's (Mereny et al 2017, Milenković at al 2015, Slavova et al 2023). Out of large set of ITS sequences, Mereny at al. (2017) described T. cryptobrumale as connected to Pannonian region, but two other genetically quite distinctive populations were not distinguished as species. In this contribution, we have analyzed larger set of sequences and their habitats and detected strong connection between specimens with specific ITS/LSU region variants to ecologically specific habitats of Balkan peninsula. Soils and vegetation where these specimens have been detected rather resemble descriptions of T. melanosporum sites in Italy, while habitats of T. cryptobrumale resemble those of T. magnatum. Additionally, we have detected numerous populations of T. melanosporum in the coastal regions of Croatia, while this species has never been officially detected eastern from Dinaric alps in Balkan peninsula. We hypothesize that T. melanosporum could never overcome low temperatures of high and long Dinaric massive and is therefore localized in the western Mediterranean regions. This could be the reason why the melanosporum clade has been highly diversifying in Balkan regions. Moreover, the genetic variant widely distributed all over Europe and described as “T. brumale” has never been detected in the Balkans. Therefore, we propose that ecologically and genetically specific taxon that is widespread only in Balkan peninsula (and to some extent northwards) should be recognized as a different species - Tuber balkanicum

O poder e a luta pela propriedade da terra no vale do rio Iconha/Piúma: o caso Thomaz Dutton Junior (1870-1906)

Ao chegar ao povoado de Piúma, região sul capixaba, por volta dos anos iniciais da década de 1870, Thomaz Dutton Junior, inglês de nascimento e mais tarde naturalizado brasileiro, desejava fazer parte da boa sociedade e ter direito a todas as prerrogativas que o grupo proporcionaria. No território de Piúma, adquiriu boa parte da massa falida de João Baptista Rodocanachi, um comerciante grego de grosso trato que explorava madeiras de lei e as comercializava para construção civil e naval. Na fazenda Monte Bello, após instalar colonos ingleses, Thomaz Dutton se envolveu em querelas jurídico-fundiárias com mandões do lugar com quem tinha relações interdependentes, sobretudo com Alexandrino Pires Martins e José Gonçalves Costa Beiriz, que ocultavam, ao fim e ao cabo, um complexo jogo por disputas políticas locais, por prestígio, por boa reputação e poder. No seio dessas disputas estava a propriedade da terra, símbolo de poder e mando, que o levou à insolvência. Este estudo investiga a trajetória de Thomaz Dutton, pautando-se na teoria da Configuração de Norbert Elias associada à teoria do Poder Simbólico de Pierre Bourdier. Objetiva compreender a maneira como as práticas do poder são materializadas nas relações sociais, identificando a aprendizagem extraída de relações interdependentes bem como os valores construídos a partir delas. Parte de análises de fontes documentais, como relatórios presidenciais provinciais, requerimentos, atas, cartas e artigos de jornais corpus documental, dominante nesta investigação , buscando vestígios no conteúdo dos discursos ali inseridos para poder descortinar as tramas do tecido social com lentes de objetivas aumentadas. Desse modo, torna possível trazer à tona a história local do território do vale do Iconha/Piúma no espaço de tempo entre 1870 e 1906 e assim expor suas particularidades e singularidades, inserindo-a no contexto da história regional capixaba e nacional. Destarte, usando o alicerce teórico-metodológico já apresentado, destaca as particularidades e feitos do passado da sociedade piumense que ainda estavam fora do campo de experiência e precisavam ser conhecidas para fazer parte da História do Espírito Santo

Périgord black truffle genome uncovers evolutionary origins and mechanisms of symbiosis

LetterInternational audienceThe Périgord black truffle ($Tuber\ melanosporum$ Vittad.) and the Piedmont white truffle dominate today's truffle market. The hypogeous fruiting body of $T.\ melanosporum$ is a gastronomic delicacy produced by an ectomycorrhizal symbiont endemic to calcareous soils in southern Europe. The worldwide demand for this truffle has fuelled intense efforts at cultivation. Identification of processes that condition and trigger fruit body and symbiosis formation, ultimately leading to efficient crop production, will be facilitated by a thorough analysis of truffle genomic traits. In the ectomycorrhizal $Laccaria\ bicolor$, the expansion of gene families may have acted as a 'symbiosis toolbox'. This feature may however reflect evolution of this particular taxon and not a general trait shared by all ectomycorrhizal species. To get a better understanding of the biology and evolution of the ectomycorrhizal symbiosis, we report here the sequence of the haploid genome of $T.\ melanosporum$, which at $\sim$125 megabases is the largest and most complex fungal genome sequenced so far. This expansion results from a proliferation of transposable elements accounting for $\sim$58% of the genome. In contrast, this genome only contains $\sim$7,500 protein-coding genes with very rare multigene families. It lacks large sets of carbohydrate cleaving enzymes, but a few of them involved in degradation of plant cell walls are induced in symbiotic tissues. The latter feature and the upregulation of genes encoding for lipases and multicopper oxidases suggest that $T.\ melanosporum$ degrades its host cell walls during colonization. Symbiosis induces an increased expression of carbohydrate and amino acid transporters in both $L.\ bicolor$ and $T.\ melanosporum$, but the comparison of genomic traits in the two ectomycorrhizal fungi showed that genetic predispositions for symbiosis $-$'the symbiosis toolbox'$-$ evolved along different ways in ascomycetes and basidiomycete

The impact of chest CT body composition parameters on clinical outcomes in COVID-19 patients

We assessed the impact of chest CT body composition parameters on outcomes and disease severity at hospital presentation of COVID-19 patients, focusing also on the possible mediation of body composition in the relationship between age and death in these patients. Chest CT scans performed at hospital presentation by consecutive COVID-19 patients (02/27/2020-03/13/2020) were retrospectively reviewed to obtain pectoralis muscle density and total, visceral, and intermuscular adipose tissue areas (TAT, VAT, IMAT) at the level of T7-T8 vertebrae. Primary outcomes were: hospitalization, mechanical ventilation (MV) and/or death, death alone. Secondary outcomes were: C-reactive protein (CRP), oxygen saturation (SO2), CT disease extension at hospital presentation. The mediation of body composition in the effect of age on death was explored. Of the 318 patients included in the study (median age 65.7 years, females 37.7%), 205 (64.5%) were hospitalized, 68 (21.4%) needed MV, and 58 (18.2%) died. Increased muscle density was a protective factor while increased TAT, VAT, and IMAT were risk factors for hospitalization and MV/death. All these parameters except TAT had borderline effects on death alone. All parameters were associated with SO2 and extension of lung parenchymal involvement at CT; VAT was associated with CRP. Approximately 3% of the effect of age on death was mediated by decreased muscle density. In conclusion, low muscle quality and ectopic fat accumulation were associated with COVID-19 outcomes, VAT was associated with baseline inflammation. Low muscle quality partly mediated the effect of age on mortality.We assessed the impact of chest CT body composition parameters on outcomes and disease severity at hospital presentation of COVID-19 patients, focusing also on the possible mediation of body composition in the relationship between age and death in these patients. Chest CT scans performed at hospital presentation by consecutive COVID-19 patients (02/ 27/2020-03/13/2020) were retrospectively reviewed to obtain pectoralis muscle density and total, visceral, and intermuscular adipose tissue areas (TAT, VAT, IMAT) at the level of T7-T8 vertebrae. Primary outcomes were: hospitalization, mechanical ventilation (MV) and/or death, death alone. Secondary outcomes were: C-reactive protein (CRP), oxygen saturation (SO2), CT disease extension at hospital presentation. The mediation of body composition in the effect of age on death was explored. Of the 318 patients included in the study (median age 65.7 years, females 37.7%), 205 (64.5%) were hospitalized, 68 (21.4%) needed MV, and 58 (18.2%) died. Increased muscle density was a protective factor while increased TAT, VAT, and IMAT were risk factors for hospitalization and MV/death. All these parameters except TAT had borderline effects on death alone. All parameters were associated with SO2 and extension of lung parenchymal involvement at CT; VAT was associated with CRP. Approximately 3% of the effect of age on death was mediated by decreased muscle density. In conclusion, low muscle quality and ectopic fat accumulation were associated with COVID-19 outcomes, VAT was associated with baseline inflammation. Low muscle quality partly mediated the effect of age on mortality

Current status of truffle cultivation: recent results and future perspectives

In this review the current status of truffle cultivation in Europe and outside Europe is reported. While the cultivation of Tuber melanosporum (Périgord black truffle), Tuber aestivum (summer or Burgundy truffle) and Tuber borchii (bianchetto truffle) gave good results, only the Italian white truffle (Tuber magnatum), which is the most expensive, has yet to be successfully cultivated. In future a revolutionary approach to truffle cultivation would be the application of mycelial inoculation techniques for producing Tuber infected plants which will allow to select the fungal strains adapted to specific climatic, edaphic conditions and hosts. The new insights which will be gained by the extensive Tuber genome sequencing programme will also help to improve truffle cultivation techniques.I tartufi sono funghi ascomiceti appartenenti all’ordine delle Pezizales anche se molti ricercatori considerano “veri tartufi” solo le specie apparteneti al genere Tuber, che comprende le specie di maggiore interesse gastronomico e commerciale quali Tuber melanosporum (tartufo nero pregiato), Tuber magnatum (tartufo bianco pregiato), Tuber aestivum (tartufo estivo o uncinato) e Tuber borchii (tartufo bianchetto). L’elevato valore economico di questi tartufi ha suscitato grande interesse riguardo la loro coltivazione fin dal lontano rinascimento. La nascita della tartuficoltura moderna, tuttavia, risale agli anni 70 in seguito alla scoperta della naura ectomicorrizica del tartufo. Oggi la tartuficoltura è diventata un’importante attività agricola in Europa e nel mondo. In Europa la produzione di T. melanosporum nelle tartufaie coltivate supera addirittura quella delle tartufaie naturali, mentre in Australia, dove il tartufo non cresce naturalmente, si ritiene che la produzione nel 2015 abbia raggiunto le 8 tonnellate. Oltre al tartufo nero pregiato sono coltivati con successo anche T. aestivum e T. borchii, mentre la coltivazione del tartufo bianco pregiato è ancora problematica. Comunque, nonostante i significativi successi raggiunti, alcune tartufaie restano improduttive o producono pochi ascomi. Ciò è conseguenza anche della mancanza di un comune regolamento europeo di certificazione delle piantine tartufigene che garantisca ai tartuficoltori la presenza di un prodotto vivaistico di qualità in tutti i mercati europei. Attualmente le piantine micorrizate sono prodotte esclusivamente mediante inoculazione sporale; l’applicazione dell’inoculazione miceliare potrebbe migliorare le tecniche di coltivazione, rendendo possibile l’impiego di ceppi geneticamente selezionati per le loro caratteristiche ecologiche e/o produttive. Il sequenziamento del genoma del tartufo nero pregiato (T. melanosporum) ha permesso di chiarire alcune fasi del ciclo biologico del tartufo; in particolare, è stato scoperto che è un fungo eterotallico e, perciò, la produzione dei corpi fruttiferi è subordinata dall’incontro di due ceppi appartenenti a “mating type” (tipo sessuale) diverso. Il sequenziamento del genoma di altre specie di tartufo potrà fornirci altre informazioni sulla loro biologia contribuendo a migliorare le tecniche di coltivazione. La genetica potrà inoltre fornirci indicazioni utili a capire il ruolo dei microrganismi associati al tartufo e magari a suggerirci approcci biotecnologici alternativi per il loro utilizzo in tartuficoltura