No Evidence Was Found for the Presence of Terreolides, Terreumols or Saponaceolides H-S in the Fruiting Bodies of Tricholoma terreum (Basidiomycota, Agaricales).

Two different collections of the gilled wild fungus Tricholoma terreum, collected in Italy, were subjected to phytochemical analysis. The fungal material was confidently identified by analysis of the ITS genomic sequences. Using both HR-LC-MS and NMR techniques, no evidence was found for the presence in the fruiting bodies of terreolides, terreumols or saponaceolides H-S, in striking contrast with the isolation of these terpenoids by Chinese authors from a mushroom collected in France and identified as T. terreum. The main cytotoxic terpenoid identified and isolated from the extracts of the specimens investigated in this work was the C30 derivative saponaceolide B, which had been previously isolated from T. saponaceum and other T. terreum collections. Although saponaceolide B is a rather labile molecule, easily degradable by heat or in acidic conditions, our study indicated that none of the extraction protocols used produced saponaceolide H-S or terreolide/terreumol derivatives, thus excluding the possibility that the latter compounds could be extraction artifacts. Considered together, these findings point to the need for the unambiguous identification of mushroom species belonging to the complex genus Tricholoma, characterized by high variability in the composition of metabolites. Moreover, based on our data, T. terreum must be considered an edible mushroom.

New Tricholomalides D-G from the Mushroom Tricholoma ustaloides Grown in an Italian Beech Wood.

Four novel seconeodolastane diterpenoids, named tricholomalides D-G, were isolated, together with the known tricholomalide C, from the fruiting bodies of Tricholoma ustaloides Romagn., a species belonging to the large Tricholoma genus of higher mushrooms (Basidiomycota, family Tricholomataceae). They were isolated through multiple chromatographic separations, and the structures, including the absolute configuration, were established through a detailed analysis of MS, NMR, and CD spectral data and comparison with related compounds reported in the literature, which has been thoroughly revised.

Near-complete de novo assembly of Tricholoma bakamatsutake chromosomes revealed the structural divergence and differentiation of Tricholoma genomes.

Tricholoma bakamatsutake, which is an edible ectomycorrhizal fungus associated with Fagaceae trees, may have diverged before the other species in Tricholoma section Caligata. We generated a highly contiguous whole-genome sequence for T. bakamatsutake SF-Tf05 isolated in an Oak (Quercus salicina) forest in Japan. The assembly of high-fidelity long reads, with a median read length of 12.3 kb, resulted in 13 chromosome-sized contigs comprising 142,068,211 bases with an average guanine and cytosine (GC) content of 43.94%. The 13 chromosomes were predicted to encode 11,060 genes. A contig (122,566 bases) presumably containing the whole circular mitochondrial genome was also recovered. The chromosome-wide comparison of T. bakamatsutake and Tricholoma matsutake (TMA_r1.0) indicated that the basic number of chromosomes (13) was conserved, but the structures of the corresponding chromosomes diverged, with multiple inversions and translocations. Gene conservation and cluster analyses revealed at least 3 phylogenetic clades in Tricholoma section Caligata. Specifically, all T. bakamatsutake strains belonged to the "bakamatsutake" clade, which is most proximal to the "caligatum" clade consisting of Tricholoma caligatum and Tricholoma fulvocastaneum. The constructed highly contiguous nearly telomere-to-telomere genome sequence of a T. bakamatsutake isolate will serve as a fundamental resource for future research on the evolution and differentiation of Tricholoma species.

New Tricholidic Acid Triterpenoids from the Mushroom Tricholoma ustaloides Collected in an Italian Beech Wood.

The secondary metabolites produced by Tricholoma ustaloides Romagn., a mushroom species belonging to the large Tricholoma genus (Basidiomycota, Tricholomataceae), are unknown. Therefore, encouraged by the interesting results obtained in our previous chemical analyses of a few Tricholoma species collected in Italian woods, we aimed to investigate the secondary metabolites of Tricholoma ustaloides. The chemical analysis involved the isolation and characterization of secondary metabolites through an extensive chromatographic study. The structures of isolated metabolites, including the absolute configuration, were established based on a detailed analysis of MS, NMR spectroscopic, optical rotation, and circular dicroism data, and on comparison with those of related compounds reported in the literature. Two novel lanostane triterpenoids, named tricholidic acids B and C, together with triglycerides, a mixture of free fatty acids, five unidentified metabolites, and the known rare saponaceolides F and J, tricholidic acid, and tricholomenyn C, were isolated from an EtOAc extract of fruiting bodies of Tricholoma ustaloides that were collected in an Italian beech wood. This is the second example of isolation of tricholidic acid derivatives from a natural source. Saponaceolides F and J exhibited high cytotoxicity (IC50 values ≤ 10 µM) against a panel of five human cancer cell lines. The toxicity against myeloid leukemia (HL-60), lung cancer (A-549), hepatocellular cancer (HepG2), renal cancer (Caki-1), and breast cancer (MCF-7) cells was higher than that shown by the very well-known cytotoxic drug cisplatin.

Encapsulation of lycopene into electrospun nanofibers from whey protein isolate-Tricholoma lobayense polysaccharide complex stabilized emulsions: Structural characterization, storage stability, in vitro release, and cellular evaluation.

In this study, lycopene-loaded nanofibers were successfully fabricated by electrospinning of oil-in-water (O/W) emulsions stabilized by whey protein isolate-polysaccharide TLH-3 (WPI-TLH-3) complexes. The lycopene encapsulated in the emulsion-based nanofibers exhibited enhanced photostability and thermostability, and achieved improved targeted small intestine-specific release. The release of lycopene from the nanofibers followed Fickian diffusion mechanism in simulated gastric fluid (SGF) and first-order model in simulated intestinal fluid (SIF) with the enhanced release rates. The bioaccessibility and cellular uptake efficiency of lycopene in micelles by Caco-2 cells after in vitro digestion were significantly improved. The intestinal membrane permeability and transmembrane transport efficiency of lycopene in micelles across Caco-2 cells monolayer were greatly elevated, thus promoting the effective absorption and intracellular antioxidant activity of lycopene. This work opens a potential approach for electrospinning of emulsions stabilized by protein-polysaccharide complexes as a novel delivery system for liposoluble nutrients with enhanced bioavailability in functional food industries.

Insights into health promoting effects and myochemical profiles of pine mushroom Tricholoma matsutake.

Tricholoma matsutake (TM) is a valuable edible mushroom that has attracted increasing attention due to its potential medicinal values and functional uses. However, the chemical composition and molecular mechanisms behinds TM are not specifically summarized yet. Hence, this review aims to systematically analyze the research progress on the characterization of chemical compositions and the reported health effects of TM in the last 20 years. The myochemical profiles of TM consist of proteins with amino acids, fatty acids, nucleic acids with their derivatives, polysaccharides, minerals, volatile components, phenolic compounds, and steroids. The bioactive substances in TM exert their health effects mainly by regulating body immunity and restoring the balance of the redox system. NF-κB signaling pathway and its downstream cytokines such as TNF-α and IL-6 are the key molecular mechanisms. In addition, MAPK, PI3K-Akt, and JAK-STAT are also involved. NF-κB, MAPK, and PI3K-Akt are also highly related to cancer regulation and thus TM has great anticancer potential. Considering that most studies have only investigated the dosage and inhibition rate of TM on cancer cell lines, more extensive studies need to focus on the specific molecular mechanisms behind these anticancer effects in the future.

Tricholosterols A-D, four new ergosterol derivatives from the mushroom Tricholoma terreum.

Four ergosterol derivatives, named tricholosterols A-D (1-4), have been isolated from the fruiting bodies of Tricholoma terreum. Their chemical structures have been determined using a combination of spectroscopic analysis as well as computational methods. Compound 1 possesses a rare D-ring opening ergosterol skeleton, while compounds 2-4 are rare degraded ergosterols. Compounds 1 and 4 exhibited moderate inhibitory activity against NO production with IC50 values of 27.6 and 31.8 µM, respectively. This is the first report of steroids from T. terreum.

Identification of upregulated genes in Tricholoma matsutake mycorrhiza.

Many plant roots associate with fungi to form mycorrhizae; tree roots especially associate with ectomycorrhizal fungi, such as Tricholoma species. Tricholoma matsutake is an economically important fungus in Asian countries and usually inhabits forests primarily composed of Pinus densiflora (Japanese red pine). In this study, to understand the mycorrhizal association between T. matsutake and P. densiflora, genes specifically expressed in mycorrhiza compared with those expressed in mycelia and fruiting bodies were identified by RNA-seq. This revealed that genes for chromatin, proteasomes, signal transduction, pheromones, cell surface receptors, cytoskeleton, RNA processing and transporters from T. matsutake were highly expressed in mycorrhiza. It also identified 35 mycorrhiza-induced small secreted proteins (MiSSPs) that were highly expressed in mycorrhiza. Meanwhile, genes for proteases, defence-related proteins, cell-wall degradation, signal transduction, pinene synthesis, plant hormones and transporters from P. densiflora were highly expressed in mycorrhiza. These genes may be involved in mycorrhizal formation and maintenance. A MiSSP, 1460819, was highly expressed in mycorrhiza, and this expression was maintained for 24 months. These results provide insight into the mycorrhizal association between T. matsutake and P. densiflora.

The ectomycorrhizal association of Tricholoma matsutake and two allied species, T. bakamatsutake and T. fulvocastaneum, with native hosts in subtropical China.

Accurate identification of edible ectomycorrhizal (ECM) mushrooms and their host trees in nature is key to commercial production for consumption. For the first time we describe the ectomycorrhizal association of the three most common species of edible matsutake mushrooms with their native host trees in Yunnan Province in China. We collected ECM samples from three different localities in subtropical forests known to be highly productive areas of Tricholoma. Additionally, we collected basidiomata of Tricholoma from the field and markets in Yunnan. ECM samples were analyzed using morphological and molecular methods. We conducted phylogenetic analyses of nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS) and analyzed the intergenic spacer of cpDNA psbA-trnH to identify basidiomata and plant hosts, respectively. Three species of Tricholoma were identified: T. bakamatsutake, T. fulvocastaneum, and T. matsutake. Four ECM associations in the study area were detected: Tricholoma bakamatsutake + Castanopsis tibetana, T. fulvocastaneum + C. tibetana, T. fulvocastaneum + Pinus yunnanensis, and T. matsutake + P. yunnanensis. Detailed descriptions and illustrations of the ECM associations are presented.

Tricholoma alpinum, sp. nov., under five-needle pines in alpine and subalpine zones in Japan.

Alpine regions in Japan are characterized by the Siberian dwarf pine, Pinus pumila. Although these regions are conserved as national parks due to their unique biome, few reports of the fungal biota are available. We examined mushroom fungi under such vegetation and found a unique yellowish-capped Tricholoma species. Multilocus molecular phylogenetic analyses and morphological observation of specimens showed that the Tricholoma species is very similar to T. fumosoluteum known in North America. The Japanese yellowish-capped T. aff. fumosoluteum had larger basidiospores and basidia and shorter pileipellis hyphae compared with T. fumosoluteum. Therefore, we describe the Japanese entity as a new species, T. alpinum.

Quantitative transcriptomic and metabolomic analyses reveal the changes in Tricholoma matsutake fruiting bodies during cold storage.

A combination of transcriptomic and metabolomic analyses was performed to systematically understand the metabolic changes in Tricholoma matsutake fruiting bodies during cold storage. In total, 800 metabolites were identified and 19,964 annotated unigenes were quantified. The unigenes related to the catabolism of proteins, carbohydrates, and lipids were mainly upregulated during cold storage, but the related primary metabolites were not accumulated, which indicated complete degradation and loss of nutrients. Concurrently, the synthesis and metabolism of the main components of the cell wall, chitin and ß-1,3-glucan, were regulated, indicating the dynamic remodeling of the T. matsutake cell wall structure. Additionally, indole-3-acetic acid and components of its synthesis pathway were found in T. matsutake, indicating their potential role as a communicator between T. matsutake and its symbiotic plants. The results provide new information to improve the understanding of the metabolic mechanism of T. matsutake fruit bodies during postharvest cold storage.

Radiocaesium in Tricholoma spp. from the Northern Hemisphere in 1971-2016.

A considerable amount of data has been published on the accumulation of radiocaesium (134Cs and particularly, 137Cs) in wild fungi since the first anthropogenically influenced releases into the environment due to nuclear weapon testing, usage and subsequently from major accidents at nuclear power plants in Chernobyl (1986) and Fukushima (2011). Wild fungi are particularly susceptible to accumulation of radiocaesium and contamination persists for decades after pollution events. Macromycetes (fruiting bodies, popularly called mushrooms) of the edible fungal species are an important part of the human and forest animal food-webs in many global locations. This review discusses published occurrences of 134Cs and 137Cs in twenty four species of Tricholoma mushrooms sourced from the Northern Hemisphere over the last five decades, but also includes some recent data from Italy and Poland. Tricholoma are an ectomycorrhizal species and the interval for contamination to permeate to lower soils layers which host their mycelial networks, results in a delayed manifestation of radioactivity. Available data from Poland, over similar periods, may suggest species selective differences in accumulation, with some fruiting bodies, e.g. T. portentosum, showing lower activity levels relative to others, e.g. T. equestre. Species like T. album, T. sulphurescens and T. terreum also show higher accumulation of radiocaesium, but reported observations are few. The uneven spatial distribution of the data combined with a limited number of observations make it difficult to decipher any temporal contamination patterns from the observations in Polish regions. When data from other European sites is included, a similar variability of 137Cs activity is apparent but the more recent Ukrainian data appears to show relatively lower activities. 40K activity in mushrooms which is associated with essential potassium, remains relatively constant. Further monitoring of 137Cs activity in wild mushrooms would help to consolidate these observations.

Geosmin synthase ges1 knock-down by siRNA in the dikaryotic fungus Tricholoma vaccinum.

Genetic manipulation for generating knock-out experiments is essential in deciphering the precise function of a gene. However, dikaryotic fungi pose the inherent challenge of having two allelic versions of each gene, one in each nucleus. In addition, they often are slow-growing and do not withstand protoplasting, which is why Agrobacterium tumefaciens-mediated transformation has been adapted. To obtain knock-out strains, however, is not feasible with a mere deletion construct transformation and screening for deletions in both nuclear copies. Hence, a convenient method using chemically synthesized dicer substrate interfering RNA (DsiRNA) for posttranscriptional interference of targeted mRNA was developed, based on the fungal dicer/argonaute system inherent in fungi for sequence recognition and degradation. A proof-of-principle using this newly established method for knock-down of the volatile geosmin is presented in the dikaryotic fungus Tricholoma vaccinum that is forming ectomycorrhizal symbiosis with spruce trees. The gene ges1, a terpene synthase, was transcribed with a 50-fold reduction in transcript levels in the knockdown strain. The volatile geosmin was slightly reduced, but not absent in the fungus carrying the knockdown construct pointing at low specificity in other terpene synthases known for that class of enzymes.

Dynamic evolution of eukaryotic mitochondrial and nuclear genomes: a case study in the gourmet pine mushroom Tricholoma matsutake.

Fungi, as eukaryotic organisms, contain two genomes, the mitochondrial genome and the nuclear genome, in their cells. How the two genomes evolve and correlate to each other is debated. Herein, taking the gourmet pine mushroom Tricholoma matsutake as an example, we performed comparative mitogenomic analysis using samples collected from diverse locations and compared the evolution of the two genomes. The T. matsutake mitogenome encodes 49 genes and is rich of repetitive and non-coding DNAs. Six genes were invaded by up to 11 group I introns, with one cox1 intron cox1P372 showing presence/absence dynamics among different samples. Bioinformatic analyses suggested limited or no evidence of mitochondrial heteroplasmy. Interestingly, hundreds of mitochondrial DNA fragments were found in the nuclear genome, with several larger than 500 nt confirmed by PCR assays and read count comparisons, indicating clear evidence of transfer of mitochondrial DNA into the nuclear genome. Nuclear DNA of T. matsutake showed a higher mutation rate than mitochondrial DNA. Furthermore, we found evidence of incongruence between phylogenetic trees derived from mitogenome and nuclear DNA sequences. Together, our results reveal the dynamic genome evolution of the gourmet pine mushroom.

Effects of Tricholoma matsutake (Agaricomycetes) Extracts on Promoting Proliferation of HaCaT Cells and Accelerating Mice Wound Healing.

Tricholoma matsutake is popular in Asian countries because of its edibility and medicinal use. T. matsutake is a precious natural medicinal fungus, and it is widely used in food and biological products. This study aimed to explore the mechanism of T. matsutake on promoting proliferation of human immortalized keratinocyte (HaCaT) cells and accelerating wound healing in mice. The MTT assay was used to test the effects of three different T. matsutake extracts (0, 62.5, 125, 250, 500, and 1000 µg/mL) on HaCaT cell viability. HaCaT cells were treated with the three T. matsutake extracts (100, 500 µg/mL) and morphological and biophysical properties were detected by atomic force microscopy with JPK data processing. Western blot analysis detected Notch signaling pathways of HaCaT cells treated with 50% ethanol extract of T. matsutake (50%T) for 24 h (100, 500 and 1000 µg/mL). Mouse wounds were treated with 50%T for 15 days. Wound healing effects were observed on the back skin of mice at different times. The quality of wound healing was estimated by histological staining (hematoxylin and eosin and Masson's trichrome). All data were counted by GraphPad Prism 5 software. The increased concentration of T. matsutake remarkably promoted HaCaT cell proliferation. The Young's modulus of HaCaT cells showed the biggest increase from 1.73 ± 0.13 kPa (0 µg/mL) to 4.57 ± 0.16 kPa (500 µg/mL) in the 50%T group. The Notch1/Jagged1 pathways were upregulated with an increase in concentration (0, 100, 500, and 1000 µg/mL). Moreover, compared with the negative and positive control groups, T. matsutake promoted wound healing in mice by epidermal regeneration, subepidermal tissue formation, and collagen deposition. The results showed that T. matsutake promotes not only proliferation of HaCaT cells but also wound healing in mice.

Climatic ecological suitability and potential distribution of Tricholoma matsutake in western Sichuan Plateau, China based on MaxEnt model.

Based on the distribution data of Tricholoma matsutake obtained from field investigation and literature, the ecological-niche factor analysis (ENFA) and the maximum entropy model (MaxEnt) were used to simulate the distribution law and suitable area of T. matsutake in the western Sichuan Plateau. The prediction was made for the future changes in the suitable area of T. matsutake by analyzing the relationship between climate factors and dynamic distribution. The results showed that the area under curve (AUC) values of both the model training set and validation set were greater than 0.90, indicating that the model prediction results were extremely accurate. The environmental variables affecting the potential distribution of T. matsutake were mainly the lowest temperature in the coldest month, the coldest season precipitation, annual temperature difference and soil type, with accumulative contribution of 90.3%. The niche parameters of suitable distribution areas of T. matsutake were as follows: the lowest temperature in the coldest month was -18.5--5.4 ℃, the coldest season precipitation was less than 15.7 mm, the annual temperature difference was 39.5-45 ℃, and soil type was semi-leached soil, including dry red soil, cinnamon soil, gray cinnamon soil, black soil and grey forest soil. The suitable areas of T. matsutake were distributed in the southwest, south, central and east of the plateau at an altitude range of 1900-3600 m. The highly suita-ble areas were mainly distributed in some towns of Yajiang, Xiangcheng, Kangding, Jiulong, Daocheng, Litang, Batang, Danba, Maerkang, Xiaojin, Jinchuan, Lixian, Maoxian, etc. The moderately and lowly suitable areas were located in some towns of Derong, Daofu, Xinlong, Luhuo, Baiyu, Luding, Rangtang, Wenchuan, Heishui, Jiuzhaigou. The highly suitable areas were discontinuously distributed according to the direction of rivers and mountains. The moderately suitable areas were connected with the highly suitable areas, while the lowly suitable areas were the extension of the highly and moderately suitable areas. Future climate change would be beneficial to the growth of T. matsutake on the western Sichuan Plateau, while the climate-suitable areas would show an overall increasing trend. Suitable areas in the low-altitude Minjiang River Basin would be more affected by climate change than those located in high-altitude areas.

Potential Mechanisms Mediating the Protective Effects of Tricholoma matsutake-Derived Peptides in Mitigating DSS-Induced Colitis.

Intestinal barrier dysfunction and inflammatory cytokine secretion play crucial roles in inflammatory bowel disease (IBD). Herein, we investigated the protective effects of Tricholoma matsutake-derived peptides SDIKHFPF and SDLKHFPF against dextran sulfate sodium-induced colitis. Both peptides alleviated colitis signs, including diarrhea, weight loss, bloody stools, colon shortening, and histopathological changes, while reducing mucus destruction, goblet cell exhaustion, and intestinal permeability. SDIKHFPF and SDLKHFPF protected the barrier function by promoting the expression of tight junction (TJ) zonula occludens-1 and occludin within the colon, as well as attenuating colonic inflammation through myeloperoxidase and pro-inflammatory cytokine suppression. Western blotting indicated that the peptides suppressed myosin light chain kinase (MLCK) and nuclear factor kappa B (NF-κB) levels, inhibiting MLC phosphorylation. SDLKHFPF was more potent than SDIKHFPF. These findings suggest that peptide SDLKHFPF mitigates colitis by regulating TJ protein expression and pro-inflammatory cytokine production via NF-κB/MLCK/p-MLC signaling, improving the barrier function.

Spore germination and ectomycorrhizae formation of Tricholoma matsutake on pine root systems with previously established ectomycorrhizae from a dikaryotic mycelial isolate of T. matsutake.

In vitro ectomycorrhizal synthesis of Tricholoma matsutake with host plants has been widely conducted to elucidate fungal symbiotic properties for future cultivation practices. Here, we report on the importance of basidiospore inocula for this fungus to provide ectomycorrhizal seedlings in vitro. Ectomycorrhizal pine seedlings synthesized in vitro with cultured mycelium of T. matsutake (isolate #45 or #84) in a 250-mL culture vessel (soil volume) were transplanted to a large 1-L culture vessel. Fresh basidiospores of this fungus were aseptically inoculated on the ectomycorrhizal root system. The ectomycorrhizal seedlings in the 1-L vessel were grown for 9 months, and some plants were further grown for 6 more months under non-aseptic conditions in 4.1-L jars. The ectomycorrhizal seedlings previously inoculated with isolate #84 in the 1-L vessel showed significant ectomycorrhizal biomass (mycorrhizal root length) after spore inoculation. The ectomycorrhizal seedlings in the 4.1-L vessel showed large shiro structures (> 10 cm in diameter). PCR amplification of intergenic spacer 1 of the rRNA gene and long terminal repeat retroelement of T. matsutake in ectomycorrhizal root tips in both the 1-L vessels and 4.1-L jars revealed the presence of amplicons of the previously inoculated culture isolate of T. matsutake and the new genet(s) that established via germination of the inoculated basidiospores. This is the first report that inoculated basidiospores of T. matsutake germinated and colonized the host root to generate ectomycorrhizae in vitro.

New acetylenic metabolites from the toxic mushroom Tricholoma pardinum.

Four unprecedented acetylenic alcohols, (Z)-non-7-en-5-yn-1,2,4-triol (1), (Z)-non-7-en-5-yn-1,4-diol (2), (Z)-1,2-dihydroxynon-7-en-5-yn-4-one (3), and (Z)-1-hydroxynon-7-en-5-yn-4-one (4) were isolated from the poisonous mushroom Tricholoma pardinum (Agaricales, Basidiomycota), together with the known compounds 1H-indole-3-carbaldehyde (5) and 6-hydroxy-1H-indole-3-carbaldehyde (6). Their structures were determined by NMR and IR spectroscopy, and mass spectrometry. The crude acetone extract of the mushroom showed potent anti-arthropod activity against Tetranychus urticae (Acarinae), a dangerous crop pest.[Figure: see text].

Phytohormones and volatile organic compounds, like geosmin, in the ectomycorrhiza of Tricholoma vaccinum and Norway spruce (Picea abies).

The ectomycorrhizospheric habitat contains a diverse pool of organisms, including the host plant, mycorrhizal fungi, and other rhizospheric microorganisms. Different signaling molecules may influence the ectomycorrhizal symbiosis. Here, we investigated the potential of the basidiomycete Tricholoma vaccinum to produce communication molecules for the interaction with its coniferous host, Norway spruce (Picea abies). We focused on the production of volatile organic compounds and phytohormones in axenic T. vaccinum cultures, identified the potential biosynthesis genes, and investigated their expression by RNA-Seq analyses. T. vaccinum released volatiles not usually associated with fungi, like limonene and ß-barbatene, and geosmin. Using stable isotope labeling, the biosynthesis of geosmin was elucidated. The geosmin biosynthesis gene ges1 of T. vaccinum was identified, and up-regulation was scored during mycorrhiza, while a different regulation was seen with mycorrhizosphere bacteria. The fungus also released the volatile phytohormone ethylene and excreted salicylic and abscisic acid as well as jasmonates into the medium. The tree excreted the auxin, indole-3-acetic acid, and its biosynthesis intermediate, indole-3-acetamide, as well as salicylic acid with its root exudates. These compounds could be shown for the first time in exudates as well as in soil of a natural ectomycorrhizospheric habitat. The effects of phytohormones present in the mycorrhizosphere on hyphal branching of T. vaccinum were assessed. Salicylic and abscisic acid changed hyphal branching in a concentration-dependent manner. Since extensive branching is important for mycorrhiza establishment, a well-balanced level of mycorrhizospheric phytohormones is necessary. The regulation thus can be expected to contribute to an interkingdom language.