Transcript Profiling Reveals Novel Marker Genes Involved in Fruiting Body Formation in Tuber borchii

Abstract

cDNA arrays were used to explore mechanisms controlling fruiting body development in the truffle Tuber borchii. Differences in gene expression were higher between reproductive and vegetative stage than between two stages of fruiting body maturation. We suggest hypotheses about the importance of various physiological processes during the development of fruiting bodies.Irrespective of their nutritional strategies, most saprotrophic and mycorrhizal fungi produce conspicuous fruiting bodies where hyphae aggregate, produce pseudotissues with differentiated compartments, develop specialized structures, and eventually differentiate meiotic spores. Among them, the ectomycorrhizal truffles (Tuber spp.) produce hypogeous ascocarps which are highly appreciated and commercialized for their delicate organoleptic properties. Since truffle fruiting bodies cannot yet be obtained under controlled conditions, our knowledge of the morphogenetic events leading to ascocarp development and maturation (3), as well as their underlying molecular bases (1,4,8,12), is quite limited. Elucidating the spatiotemporal control of gene expression during the successive stages of the truffle life cycle will improve our knowledge of processes that initiate and coordinate the formation of hypogeous truffles. Here, we describe changes in gene expression during the formation of the ascomata of Tuber borchii.Unripe (CF05; 0 to 5% mature spores) and ripe (CF70; 70 to 100% mature spores) T. borchii fruiting bodies were collected under hazelnut trees from a natural truffle ground near Alba in Piedmont (Italy) during the 2000 to 2001 production seasons. RNA was extracted as described by Lacourt et al. (4). cDNA libraries were constructed using the PCR-based SMART cDNA library construction kit in TriplEx2 (Clontech, Palo Alto, CA) (2). A cDNA array containing 2,041 elements was produced, hybridized, and analyzed according to Duplessis et al. (2). Six cDNA complex probes were then prepared from total RNA of two CF05 ascomata, two CF70 ascomata, and vegetative mycelium (4).During fruiting body development, the vast majority of genes were not significantly regulated among the different stages. However, comparisons between fruiting bodies and mycelium indicated that 69 nonredundant transcripts (i.e., 3%) showed significant changes in expression (analysis of variance, P Ͻ 0.01) ( (Table S1 in the supplemental material) showed an increased synthesis (Ն2.5) in unripe (CF05) compared to ripe (CF70) fruiting bodies, while none was more expressed in CF70 than CF05. These genes are highly similar to fungal hypothetical proteins of unknown function from other ascomycete species, e.g., Aspergillus nidulans, Gibberella zeae, and Magnaporthe grisea. They likely belong to a set of genes of unknown function involved in sexual development in ascomycetous fungi.Differential expression of four differentially expressed genes representing genes related to lipid metabolism (HMG-CoA synthase, acetyl-CoA acetyltransferase [ACAT], isopentenyl diphosphate isomerase [IPPI]), and str...

The Perigord black truffle responds to cold temperature with an extensive reprogramming of its transcriptional activity

“…The membrane lipids change their desaturation degree, length, configuration and the degree of cyclization of the acyl chains in the presence of temperature stress ( Feofilova et al, 2000) in order to maintain membrane fluidity (Steels et al, 1994). Previous works on T. borchii demonstrated that the lipid metabolism plays a key role in the reproductive stage ( Lacourt et al, 2002 andGabella et al, 2005); in particular, genes involved in the synthesis of ergosterol have been up-regulated in fruiting bodies (Gabella et al, 2005).…”

Mining gene expression data with pattern structures in formal concept analysis

“…The fruit-body is a specific fungal organ that differentiate in order to produce spores and that further ensure spore dispersal in nature [30]. Previous gene expression analyses of the fruit-body development conducted in the ectomycorrhizal fungus Tuber borchii also reported the strong induction of several genes involved in carbon and nitrogen metabolisms [13] as well as in lipid metabolism [32]. The present results are consistent with these observations and supports an important mobilization of nutrient sources from the mycelium to the fruit-body.…”

Cloning of glyceraldehyde-3-phosphate dehydrogenase genes from the basidiomycete mushroom Pleurotus ostreatus and analysis of their expression during fruit-body development

“…In order to elucidate the precise molecular mechanism of fruitbody development, previous studies have used various molecular techniques to identify and characterize a large number of genes that are differentially expressed at various developmental stages among several mushrooms. These mushrooms include Agaricus bisporus (Ospina-Giraldo et al 2000), Agrocybe aegerita (Wang et al 2013), Antrodia cinnamomea (Chu et al 2008), Coprinopsis cinerea (Cheng et al 2013), Lentinula edodes (Chum et al 2011), Ganoderma lucidum (Luo et al 2010), Flammulina velutipes (Yamada et al 2006), P. ostreatus (Joh et al 2007), and Tuber borchii (Gabella et al 2005). The comprehensive analyses of these genes have provided valuable genetic and biochemical information for future studies on fruit-body differentiation in basidiomycetes.…”