François Le Tacon's research while affiliated with University of Lorraine and other places

Publications (243)

Article
Full-text available
Trees are able to colonize, establish and survive in a wide range of soils through associations with ectomycorrhizal (EcM) fungi. Proper functioning of EcM fungi implies the differentiation of structures within the fungal colony. A symbiotic structure is dedicated to nutrient exchange and the extramatricular mycelium explores soil for nutrients. Ev...
Article
Full-text available
The Périgord black truffle (Tuber melanosporum Vittad.) is an ectomycorrhizal fungus forming edible fructifications. The production of T. melanosporum relies mainly on man-made plantations. T. melanosporum is a heterothallic species requiring the meeting of two partners of opposite mating types to fruit. It is common to have productive and non-prod...
Article
Full-text available
Tuber aestivum, also known as the summer or Burgundy truffle, is an ectomycorrhizal Ascomycete associated with numerous trees and shrubs. Its life cycle occurs in the soil, and thus soil parameters such as temperature and water availability could influence it. T. aestivum cultivation has started in several countries, but ecological and agronomic re...
Article
Full-text available
The molecular mechanisms underlying mycorrhizal symbioses, the most ubiquitous and impactful mutualistic plant–microbial interaction in nature, are largely unknown. Through genetic mapping, resequencing and molecular validation, we demonstrate that a G-type lectin receptor-like kinase (lecRLK) mediates the symbiotic interaction between Populus and...
Article
Full-text available
According to isotopic labeling experiments, most of the carbon used by truffle (Tuber sp.) fruiting bodies to develop underground is provided by host trees, suggesting that trees and truffles are physically connected. However, such physical link between trees and truffle fruiting bodies has never been observed. We discovered fruiting bodies of Tube...
Article
Full-text available
Ecto- and endo-mycorrhizal colonization of Populus roots have a positive impact on the overall tree health and growth.A complete molecular understanding of these interactions will have important implications for increasing agricultural or forestry sustainability using plant: microbe-based strategies. These beneficial associations entail extensive m...
Article
Full-text available
From 1903–1904 to 1988–1989, the two World Wars and sociological factors as rural desertification and changes in land uses mainly explained the decline of black truffle production in the Vaucluse department, which well reflects that of the whole of France. These can be correlated with the annual climatic variations as well as, from 1924–1925 to 194...
Article
Full-text available
Tuberaceae is one of the most diverse lineages of symbiotic truffle-forming fungi. To understand the molecular underpinning of the ectomycorrhizal truffle lifestyle, we compared the genomes of Piedmont white truffle (Tuber magnatum), Périgord black truffle (Tuber melanosporum), Burgundy truffle (Tuber aestivum), pig truffle (Choiromyces venosus) an...
Poster
Full-text available
Ectomycorrhizal (ECM) fungi are essential for forest ecosystems. In exchange for carbohydrates, ECM fungi offer an improved mineral supply to trees. Proper functioning of ECM implies differentiation as well as communication and nutrition exchange within the fungal colony. Fungal hyphae surround root tips of host trees and penetrate between their ro...
Article
Fungi as a Source of Food, Page 1 of 2 Abstract In this article, we review some of the best-studied fungi used as food sources, in particular, the cheese fungi, the truffles, and the fungi used for drink fermentation such as beer, wine, and sake. We discuss their history of consumption by humans and the genomic mechanisms of adaptation during art...
Article
The P?rigord black truffle (Tuber melanosporum Vittad.) is a heterothallic ascomycete that establishes ectomycorrhizal symbiosis with trees and shrubs. Small-scale genetic structures of female genotypes in truffle orchards are known, but it has not yet been studied in male genotypes. In this study, our aim was to characterize the small-scale geneti...
Article
Full-text available
Quelques considérations sur le réensemencement par ascospores des truffières à [i]Tuber melanosporum[/i]
Article
Full-text available
The Périgord black truffle, Tuber melanosporum Vittad., is an ectomycorrhizal fungus that forms edible hypogeous ascomata. It is now harvested in plantations and is recognized as an agricultural product by European policy. Empirical techniques without scientific demonstration of their efficiency are often used to improve the production of truffles...
Article
Full-text available
Fungi display a rich variety of sexual reproduction systems and are therefore good models to investigate sex evolution. Moreover, understanding the investment in sexual reproduction of edible fungi is a critical challenge for improving their cultivation. The Perigord black truffle (Tuber melanosporum Vittad.) is a heterothallic ascomycete associate...
Chapter
Tuber aestivum Vittad. is characterized by a broad ecological amplitude and geographical distribution. It is the most widespread truffle species found in Europe. Tuber aestivum is mainly harvested in natural habitats and in previously cultivated soils recolonized by ectomycorrhizal tree species. Production in orchards is less common. In this chapte...
Chapter
The European species Tuber melanosporum and the Asian species T. indicum are phylogenetically and morphologically very close. T. indicum is formed by a complex of cryptic species or ecotypes spread from India to Japan, while T. melanosporum is a well-defined species localised in South of Europe. T. melanosporum has been harvested and consumed in Eu...
Chapter
In China, Tuber indicum occurs naturally in subtropical evergreen oak forests and in deciduous broad-leaved forests. Most of these forests, however, have been replaced by Pine plantations, which currently represent the major habitats where T. indicum is found. Pinus yunnanensis, Pinus armandii and Keteleeria evelyniana are currently the most common...
Chapter
In this chapter, the past migrations of the genus Tuber are first analysed. Then the current natural distribution of the main commercialised species related to current climatic characteristics is described. Very little data exists concerning the relationship between ascoma production and climatic conditions in natural forests or plantations. An ana...
Article
Full-text available
Ectomycorrhizae create a multitrophic ecosystem formed by the association between tree roots, mycelium of the ectomycorrhizal fungus, and a complex microbiome. Despite their importance in the host tree’s physiology and in the functioning of the ectomycorrhizal symbiosis, detailed studies on ectomycorrhiza-associated bacterial community composition...
Data
Figure S1. Multivariate analyses of the bacterial communities associated with T. melanosporum ectomycorrhizal root tip, bulk soil and ascocarps (peridium and gleba) in November (A), December (B) and January (C). MBS: bulk soil, MYCO: ectomycorrhizal root tip, AIN: gleba, AOUT: peridium.
Article
Full-text available
Background and aims We previously showed by 13CO2 host labelling that almost all of the constitutive carbon allocated to the truffles originated from the host. The objective of this present work was to determine the putative capacity of T. melanosporum ectomycorrhizas and ascocarps to use soil carbon and to uptake or assimilate soil nitrate. Method...
Article
Full-text available
Key message Several aspects of the life cycle of the Périgord black truffle have been elucidated only recently, while others remain either controversial or unstudied. In this paper, we present a revised life cycle of this fungus and highlight key aspects that have yet to be addressed or require further understanding.• ContextThe hypogeous sporophor...
Article
La localisation ultrastructurale des activités phosphatasiques acides est recherchée dans deux associations ectomycorhiziennes à Basidiomycètes, obtenues en conditions contrôlées.
Article
Production of the black truffle (Tuber melanosporum Vittad.) has experienced a decline in France over the last century. Different sociological factors as well as climate change have been suggested as possible explanations for this decline. The aims of this study were to assess the effects of annual climatic variations on black truffle sales by anal...
Article
Full-text available
Although truffles are cultivated since decades, their life cycle and the conditions stimulating ascocarp formation still remain mysterious. A role for bacteria in the development of several truffle species have been suggested but few is known regarding the natural bacterial communities of Périgord Black truffle. Thus, the aim of this study was to d...
Article
Full-text available
Truffles ascocarps need carbon to grow, but it is not known whether this carbon comes directly from the tree (heterotrophy) or from soil organic matter (saprotrophy). The objective of this work was to investigate the heterotrophic side of the ascocarp nutrition by assessing the allocation of carbon by the host to Tuber melanosporum mycorrhizas and...
Article
Full-text available
Almost all terrestrial plant species form mutualistic associations with soil fungi. Their roots are infected with mycorrhizal fungi which contribute to their mineral nutrition and benefit the plants in a number of other ways. This type of association is one aspect of the serial symbiosis theory which Is now considered as an essential mechanism of e...
Article
The development of high-throughput methods such as pyrosequencing and microarrays has greatly improved our understanding of the microbial diversity in complex environments such as soils. Nevertheless, albeit advancements in such techniques, the first major step is to obtain high quantity and good quality genomic DNA (gDNA). The work presented here...
Article
Full-text available
The genetic structure of ectomycorrhizal (ECM) fungal populations results from both vegetative and sexual propagation. In this study, we have analysed the spatial genetic structure of Tuber melanosporum populations, a heterothallic ascomycete that produces edible fruit bodies. Ectomycorrhizas from oaks and hazels from two orchards were mapped and g...
Book
L’arboretum d’Amance est situé à 13 kilomètres à l’Est de Nancy, sur le territoire de la commune d’Amance. Il a été créé en 1900 par l’Ecole forestière avec deux objectifs : la connaissance du comportement d’espèces exotiques en lorraine et la mise en place d’un outil de reconnaissance dendrologique. Cet ouvrage, nouvellement mis en page et richeme...
Data
Table showing the percentage of identity of multiple alignment of TE copies corresponding to 175 consensus TE families identified by the RMBLR procedure. (DOCX)
Article
Full-text available
Background The publicly available Laccaria bicolor genome sequence has provided a considerable genomic resource allowing systematic identification of transposable elements (TEs) in this symbiotic ectomycorrhizal fungus. Using a TE-specific annotation pipeline we have characterized and analyzed TEs in the L. bicolor S238N-H82 genome. Methodology/Pr...
Article
Full-text available
A Populus deltoides × Populus trichocarpa F1 pedigree was analyzed for quantitative trait loci (QTLs) affecting ectomycorrhizal development and for microarray characterization of gene networks involved in this symbiosis. A 300 genotype progeny set was evaluated for its ability to form ectomycorrhiza with the basidiomycete Laccaria bicolor. The perc...
Article
Full-text available
Container-grown Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings were inoculated at the time of sowing with a Laccariabicolor (Maire) Orton mycelial suspension produced in a fermentor. They were grown in a peat moss–vermiculite substrate under four levels of N fertilization (7.2, 14.4, 21.6, and 28.7 mg/seedling per season (N1, N2, N3, a...
Article
Epigeous saprotrophic and ectomycorrhizal (ECM) fungal sporocarps were assessed during 7 yr in a French temperate experimental forest site with six 30-year-old mono-specific plantations (four coniferous and two hardwood plantations) and one 150-year-old native mixed deciduous forest. A total of 331 fungal species were identified. Half of the fungal...
Article
In a nursery in the centre of France, we have compared the effect of different forms of an ectomycorrhizal fungus inoculum (Hebeloma cylindrosporum) on growth and mycorrhizal development of Douglas-fir and Norway spruce after soil fumigation. Compared with inoculum produced on peat and vermiculite, the inoculum produced in a fermentor and entrapped...
Article
Survival of Hebeloma crustuliniforme (Bulliard ex Fries) Quelet, grown in a liquid medium and subsequently entrapped in beads of calcium alginate, was tested under different conditions. Mycelium viability was not affected either by curing the beads for up to 22 h in 0.7 M CaCl2 or by the addition of either peat or bentonite to the alginate gel. Bot...
Article
The objective of this study was to determine the different effects of three ectomycorrhizal fungi (Laccaria laccata, Hebeloma crustuliniforme, and Thelephora terrestris) on the growth and mineral nutrition of Pinus silvestris at different levels of soluble phosphorus. Even a low intensity of infection by Laccaria laccata stimulated Pinus silvestris...
Article
Full-text available
It is becoming clear that simple sequence repeats (SSRs) play a significant role in fungal genome organization, and they are a large source of genetic markers for population genetics and meiotic maps. We identified SSRs in the Laccaria bicolor genome by in silico survey and analyzed their distribution in the different genomic regions. We also compa...
Article
Full-text available
The impact of ectomycorrhiza formation on the secretion of exoenzymes by the host plant and the symbiont is unknown. Thirty-eight F(1) individuals from an interspecific Populus deltoides (Bartr.)×Populus trichocarpa (Torr. & A. Gray) controlled cross were inoculated with the ectomycorrhizal fungus Laccaria bicolor. The colonization of poplar roots...
Article
The fungal symbionts forming ectomycorrhizas, as well as their associated bacteria, benefit forest trees in a number of ways although the most important is enhancing soil nutrient mobilization and uptake. This is reciprocated by the allocation of carbohydrates by the tree to the fungus through the root interface, making the relationship a mutualist...
Article
Les boutures d'épicéa commun peuvent être mycorhizées artificiellement par la souche S 238 de Laccaria laccata, au repiquage sur planche désinfectée. Un des premiers essais effectué en pépinière montre que ces plants ont été rapidement, fortement et durablement mycorhizés par la souche inoculée. De plus, l'inoculation a amélioré la survie, la crois...
Article
A fertilization experiment was set up in 1969 in a mature fir forest (Abies alba Mill.) in the Vosges Mountains in France, at an elevation of 800 m, on poor granites. It consists of 65 plots (250 m2), divided into 8 treatments: control, N, P, Ca, N+P, N+Ca, P+Ca, N+P+Ca. The quantities of fertilizers were: 200 kg.ha-1 N, 150 kg.ha-1 P2O5, 1500 kg.h...
Article
Georges Louis LECLERC, Comte de Buffon, a certainement été un des premiers, sinon le premier, à comprendre la nécessité d'une recherche forestière et cela. au début du 18e siècle. Il a non seulement posé les grands principes de la recherche forestière, mais il a lui-même entrepris pendant quarante ans toute une série d'expériences. Il a ainsi ouver...