Query: Mycorrization  tuber magnatum

title: Tuberomics: a molecular profiling for the adaption of edible fungi (Tuber magnatum Pico) to different natural environments
abstract: Truffles are symbiotic fungi that develop underground in association with plant roots, forming ectomycorrhizae. They are primarily known for the organoleptic qualities of their hypogeous fruiting bodies. Primarily, Tuber magnatum Pico is a greatly appreciated truffle species mainly distributed in Italy and Balkans. Its price and features are mostly depending on its geographical origin. However, the genetic variation within T. magnatum has been only partially investigated as well as its adaptation to several environments. Here, we applied an integrated omic strategy to T. magnatum fruiting bodies collected during several seasons from three different areas located in the North, Center and South of Italy, with the aim to distinguish them according to molecular and biochemical traits and to verify the impact of several environments on these properties. With the proteomic approach based on two dimensional electrophoresis (2 DE) followed by mass spectrometry, we were able to identify proteins specifically linked to the sample origin. We further associated the proteomic results to an RNA seq profiling, which confirmed the possibility to differentiate samples according to their source and provided a basis for the detailed analysis of genes involved in sulfur metabolism. Finally, geographical specificities were associated with the set of volatile compounds produced by the fruiting bodies, as quantitatively and qualitatively determined through proton transfer reaction mass spectrometry (PTR MS) and gas chromatography mass spectrometry (GC MS) In particular, a partial least squares discriminant analysis (PLS DA) model built from the latter data was able to return high confidence predictions of sample source. Results provide a characterization of white fruiting bodies by a wide range of different molecules, suggesting the role for specific compounds in the responses and adaptation to distinct environments.

title: Genetic Structure and Phylogeography of Tuber magnatum Populations
abstract: The ectomycorrhizal fungus Tuber magnatum produces the white truffle appreciated worldwide for its unique aroma. With respect to other Tuber spp. of economic interest, T. magnatum presents a narrower geographical range. This species has, in fact, long been considered endemic to Italy. However, over the last few decades several reports have documented the presence of white truffles in different Mediterranean countries and in particular in various areas of south east Europe. In this study, samples from several Pannonian and Balkan countries such as Hungary, Serbia, Romania, Bulgaria and Greece have been collected and genotyped with microsatellite markers and the data merged with those available for Italian populations. Our objectives were to test whether Italian and south east European populations are differentiated and to evaluate the genetic diversity of T. magnatum all over its distributional range. We show the genetic structure of T. magnatum populations with the differentiation of four main groups: northern Italy, central northern Italy, southern Italy and the Balkan/Pannonian region. The present study allowed us to refine the evolutionary history of T. magnatum and track the possible post glacial expansion route of this species. The assessment of T. magnatum's genetic structure is not only of scientific relevance, but it is also important for the conservation and market traceability of this prestigious fungus.

title: Geographical based variations in white truffle Tuber magnatum truffle aroma is explained by quantitative differences in key volatile compounds
abstract: The factors that vary the aroma of Tuber magnatum fruiting bodies are poorly understood. The study determined the headspace aroma composition, sensory aroma profiles, maturity, and microbiome composition from T. magnatum originating from Italy, Croatia, Hungary, and Serbia, and tested if truffle aroma is dependent on provenance and if fruiting body volatiles are explained by maturity and/or microbiome composition. Headspace volatile profiles were determined by gas chromatography mass spectrometry olfactometry (GC MS O) and aroma of fruiting body extracts were sensorially assessed. Fruiting body maturity were estimated through spore melanisation. Bacterial community was determined using 16S rRNA amplicon sequencing. Main odour active compounds were present in all truffles but varied in concentration. Aroma of truffle extracts were sensorially discriminated by sites. However, volatile profiles of individual fruiting bodies varied more within sites than across geographic area, while maturity level did not play a role. Microbiome composition varied highly and was partially explained by provenance. A few rare bacterial operational taxonomical units associated with select few non odour active volatile compounds. Specificities of the aroma of T. magnatum truffles are more likely linked to individual properties than provenance. Some constituents of the microbiome may provide biomarkers of provenance and be linked to non odour active volatiles.

title: Map of suitability for the spontaneous growth of Tuber magnatum in Emilia Romagna (Italy)
abstract: In this work we used an inductive and deductive approach to produce the map of suitability for the spontaneous growth of Tuber magnatum (white truffle) (SSGT) in Emilia Romagna region (northern Italy) This map was produced in order to identify the environments where appropriate actions should be applied to protect this threatened truffle species. The steps used to define the map were: 1) surveying and mapping the actual productive areas (APAs) in two provinces of Emilia Romagna (Bologna and Modena) 2) identification of some morphological, climatic, vegetational and pedological properties related to T. magnatum development; 3) production of digital maps representing the value (classified) that each property assumes in discrete land portions; 4) overlapping the map of APAs with each of the thematic maps and selection of the properties showing the strongest relationships with the presence of T. magnatum 5) creating the map of SSGT, covering the whole hilly area of Emilia Romagna region; 6) assessing the reliability of the SSGT map, by overlapping the APAs map and the areas of the provinces of Parma and Piacenza where the mycelium of T. magnatum was found using species specific primers. The relationships found by means of the inductive approach (comparison between selected properties and observed frequency of truffle) demonstrated its effectiveness in predicting deductively the areas with distinct suitability for truffle.

title: Beyaz truf mantarinda (Tuber magnatum) mikrosatelit markorlerinin tum genom duzeyinde tanimlanmasi ve anotasyonu
abstract: Ektomikoriza mantari Tuber magnatum Pico, en yuksek ekonomik degere sahip truf mantari turudur. Truf mantarlarinin talep goren aroma ozellikleri ve yuksek fiyatlar ile pazarlanmalari bu mantar turlerini onemli bir arastirma konusu haline getirmekte, truf mantari aroma bilesenleri, bu mantarlarin ureme mekanizmalari, truf mantari genomlarinin karakterizasyonu, ve genetik cesitlilik ve populasyon yapilarinin belirlenmesi konularinda calismalar gerceklestirilmektedir. Truf mantarlari onceden dogal ormanlik arazilerden toplanir iken, 1970'lerde fidan inokulasyon protokollerinin gelistirilmesi ile truf mantari yetistiriciligi sistematik bir tarimsal aktivite haline gelmistir. Ancak en degerli truf mantari olan T. magnatum ile fidan inokulasyonu, mikorizanin DNA temelli protokoller olmaksizin yalnizca morfolojik yontemler ile tanimlanmasindaki sorunlardan oturu yakin zamanda uygulamaya gecirilebilmistir. Bu calisma kapsaminda T. magnatum genomuna ozel mikrosatelit markorleri gelistirilmis ve fonksiyonel anotasyonlari gerceklestirilmistir. Calisma dahilinde biyoinformatik analiz yontemleri kullanilarak T. magnatum genom sekansinda mikrosatelit dizileri belirlenmis, diziler PCR markorlerine cevrilmis, markorler genom sekansinda haritalanarak alel buyuklukleri hesaplanmistir. Calisma sonucunda T.magnatum turune ozel 11 189 yeni mikrosatelit markoru gelistirilmistir. Anotasyon analizleri gerceklestirilerek T. magnatum proteinleri ile eslesen, bu sebeple fonksiyonel genomik calismalari icin ozellikle elverisli 3377 adet markor tanimlanmistir. Calisma sonucunda sunulan T. magnatum 'a ozel DNA markoru koleksiyonu bu degerli truf mantari turu icin onemli bir genomik arac kaynagi olusturmaktadir.

title: No radioactive contamination from the Chernobyl disaster in Hungarian white truffles (Tuber magnatum)
abstract: Despite being one of the most expensive gourmet foods, it remains unclear if the iconic White Truffle (Tuber magnatum Pico; hereinafter WT) accumulates radioactivity at harmful levels comparable to other fungal species. Here, we measure the active radiocaesium 137 concentration (137Cs) in ten hypogeous WT fruitbodies from southern Hungary, and the soils in which they were growing. All WTs reveal non significant 137Cs values, thus providing an 'all clear' for WT hunters in the species' northernmost habitats, where corresponding soil samples occasionally exhibit slight 137Cs concentrations. Our results are particularly relevant in the light of a rapidly increasing global demand for WTs and their subsequent trading extent and price inflation, because up to 600 kg of fresh fruitbodies are harvested each year in southern Hungary. Moreover, some of Europe's forest ecosystems, in which mushroom picking is common practise, are still contaminated with 137Cs from the Chernobyl fallout more than 30 years ago, posing a serious threat to human health.

title: First production of Italian white truffle (Tuber magnatum Pico) ascocarps in an orchard outside its natural range distribution in France.
abstract: Truffles are ectomycorrhizal species forming edible ascocarps. The Italian white truffle (Tuber magnatum Pico) is the most famous and expensive species harvested to date; it comes exclusively from natural habitats in European countries. The annual production of T. magnatum is generally insufficient to respond to the high demands making its cultivation a research hotspot. The first attempt to cultivate T. magnatum started in the 1970s without success; only recently have mycorrhized plants been successfully produced. The aims of this study were (1) to assess the persistence of T. magnatum in the soil of plantations realized with mycorrhized plants and (2) to characterize the first T. magnatum orchard that produced ascocarps outside the known natural geographic range of this species. In 2018, five orchards were sampled in France, and T. magnatum was investigated in the soil. We confirmed that T. magnatum survived in the soil 3 to 8 years after planting. The key finding of this study was the harvest of T. magnatum ascocarps in 2019 and 2020 from one orchard. The production of ascocarps started 4.5 years after planting, and the ascocarps were harvested under different trees and during two consecutive seasons. A detailed analysis of the productive orchards (i.e. soil features, soil water availability, cultivation techniques) is presented. These results demonstrate the feasibility of T. magnatum cultivation worldwide by planting mycorrhized plants. The cultivation of T. magnatum could therefore become a real opportunity for farmers and could respond to the high demand of this high priced food.

title: Geographical based variations in white truffle Tuber magnatum aroma is explained by quantitative differences in key volatile compounds.
abstract: The factors that vary the aroma of Tuber magnatum fruiting bodies are poorly understood. The study determined the headspace aroma composition, sensory aroma profiles, maturity, and bacterial communities from T. magnatum originating from Italy, Croatia, Hungary, and Serbia, and tested if truffle aroma is dependent on provenance and if fruiting body volatiles are explained by maturity and/or bacterial communities. Headspace volatile profiles were determined by gas chromatography mass spectrometry olfactometry (GC MS O) and aroma of fruiting body extracts were sensorially assessed. Fruiting body maturity were estimated through spore melanisation. Bacterial community was determined using 16S rRNA amplicon sequencing. Main odour active compounds were present in all truffles but varied in concentration. Aroma of truffle extracts were sensorially discriminated by sites. However, volatile profiles of individual fruiting bodies varied more within sites than across geographic area, while maturity level did not play a role. Bacterial communities varied highly and was partially explained by provenance. A few rare bacterial operational taxonomical units associated with select few non odour active volatile compounds. Specificities of the aroma of T. magnatum truffles are more likely linked to individual properties than provenance. Some constituents of bacteria may provide biomarkers of provenance and be linked to non odour active volatiles.

title: Co occurrence of true truffle mycelia in Tuber magnatum fruiting sites.
abstract: Tuber magnatum (the white truffle) is the most precious species of the genus Tuber which comprises the hypogeous ectomycorrhizal species called "true truffle." Despite its high economic value, the knowledge on its ecology is scant, principally due to the difficulty to find its mycorrhizas in the soil. The possibility to detect its mycelium by DNA extracted from soil has given a new chance for studying this truffle species. In this work, the co occurrence of other Tuber species with T. magnatum mycelium was investigated by using species specific primers in several productive areas located in central and northern Italy. Most (82% of the examined soil samples showed at least one other Tuber species in addition to T. magnatum. The most common was T. maculatum (72% of soil samples) followed by T. borchii, T. rufum, T. brumale, T. dryophilum, T. macrosporum, and T. melanosporum (40% 37% 22% 19% 12% and 1% of soil samples, respectively) Tuber aestivum was never detected in T. magnatum productive patches. Analysis of species co occurrence showed that the pairwise associations between T. dryophilum T. brumale, T. brumale T. borchii, and T. borchii T. dryophilum was significant. The results suggest that Tuber mycelial network in white truffle grounds is much more extensive than the distribution of their ectomycorrhizas and competitive exclusion between different Tuber species seems to take place only for root colonization.

title: Heterogeneity of the white truffle Tuber magnatum in a limited geographic area of Central Southern Italy.
abstract: Molise region (Central Southern Italy) is one of the Italian richest areas of truffles and contributes significantly to the national production of the precious Tuber magnatum. Nevertheless, Molise truffle has received little scientific attention. Accordingly, in the present study, two T. magnatum populations collected in two different sites of Molise region were characterised from a morphological, genetic and microbiological point of view. A considerable variability between and within the two analysed groups emerged, suggesting an interesting heterogeneity of Molise white truffle populations. Ascocarps of the two groups significantly differed in size and maturation degree, although no linear correlation between weight and maturity was found. Genetic investigations focused on the Sequence Characterised Amplified Region SCAR A21 inf. Three haplotypes, randomly distributed within the two truffle groups regardless of their collection sites, were detected. The 16S rRNA gene amplicon high throughput sequencing provided an overview of the composition of the ascocarp associated bacterial communities. A predominance of a Proteobacteria was observed, with Bradyrhizobium among the main genera. However, some truffles showed unusual microbial profiles, with Pedobacter, Polaromonas and other bacterial genera as dominant taxa.