Genetic variability and taxonomic position of ectomycorrhizal fungus Pisolithus from India

Eight ectomycorrhizal fungal isolates of Pisolithus associated with Eucalyptus species in different parts of India were collected and the genetic variability of these isolates was studied by ITS-RFLP and ITS sequencing. All the isolates showed same RFLP patterns with each restriction enzyme, indicating all these isolates of Pisolithus are of the same genotype. The sequence comparison of KN6 of Indian isolate showed high sequence similarities with the isolates of Pisolithus associated with Eucalyptus from Australia. Phylogeny analysis showed that all the isolates compared in this study clustered into four main groups The Indian isolate (KN6) clustered with Pisolithus albus isolates of group I, which are associated with Eucalyptus. These results suggested that Pisolithus isolates found in India are P. albus.     

Craterellus indicus sp. nov., a new species associated with Cedrus deodara from the western Himalayas, India

Craterellus indicus is proposed here as a new species, resulting from a morphological and molecular study on the diversity of Cantharellaceae in the western Himalayan region of India. The species is characterized by a pale brownish to creamish pileus and a smooth to folded hymenium that is distinctly detached from the stipe apex. There are no clamp connections. The combination of characters makes this species distinct from other known species of Craterellus. Molecular phylogenetic analysis of partial large subunit (LSU) and the ITS region of the nuclear ribosomal operon supports its position as a new species.     

Inoculum production of the ectomycorrhizal fungus Pisolithus microcarpus in an airlift bioreactor

Many important tree species in reforestation programs are dependent on ectomycorrhizal symbiosis in order to survive and grow, mainly in poor soils. The exploitation of this symbiosis to increase plant productivity demands the establishment of inoculum production methods. This study aims to propose an inoculum production method of the ectomycorrhizal fungus Pisolithus microcarpus (isolate UFSC-Pt116) using liquid fermentation in an airlift bioreactor with external circulation. The fungus grew as dark dense pellets during a batch fermentation at 25.5 degrees C and air inlet of 0.26-0.43 vvm. The maximum biomass (dry weight) achieved in the airlift bioreactor was approximately 5 g.l(-1) after 10-11 days. The specific growth rate (micro(x)) in the exponential phase was 0.576 day(-1), the yield factor (Y(X/S)) 0.418, and the productivity (P(X)) 0.480 g.l(-1).day(-1). This specific growth rate was higher than that observed by other authors during fermentation processes with other Pisolithus isolates. The method seems to be very suitable for biomass production of this fungus. However, new studies on the fungus growth morphology in this system, as well as on the efficiency of the process for the cultivation of other ectomycorrhizal fungi, are necessary. It is also necessary to test the infectivity and efficiency of the inoculum towards the hosts.     

Alachalasins A-G, new cytochalasins from the fungus Stachybotrys Podospora vesticola [corrected

Alachalasins A-G (1-7), seven new cytochalasin-type of metabolites, have been isolated from cultures of an isolate of Stachybotrys Podospora vesticola [corrected] The structures of these compounds were determined mainly by analysis of their NMR spectroscopic data, and the absolute configuration of 1 was assigned by application of the modified Mosher method. Alachalasin A (1) displayed inhibitory effect on HIV-1LAI replication in C8166 cells with an EC50 of 8.01 microM; alachalasins D (4) and G (7) showed modest antimicrobial activity.     

Lignosulfonate promotes the interaction between Scots pine and an ectomycorrhizal fungus Pisolithus tinctorius in vitro

Lignosulfonate (LS) is a lignin-based polymer obtained as a by-product from paper industry, which may have potential as an amendment with macronutrients. We studied effects of LS on the interaction between Scots pine (Pinus sylvestris L.) seedlings and hypocotyl cuttings and the ectomycorrhizal (ECM) fungusPisolithus tinctorius (Pers.) Coker and Couch. The experiments were performed in vitroon the MMN agar medium containing Fe–LS chelate at the concentrations of 0, 5, 10 and 25 mg/L. Inoculation with P. tinctoriusincreased root growth of the seedlings. Fe–LS enhanced P. tinctorius induced formation of lateral roots and had a dose-dependent positive effect on the establishment of mycorrhizas on the seedlings. The growth of the fungal mycelium was improved by Fe–LS, which might cause faster and more intensive contact with the roots and, thus, better root growth and mycorrhiza formation. P.tinctorius enhanced also adventitious root formation and subsequent root growth of the hypocotyl cuttings but without any synergistic effect with Fe–LS. Our study with P. tinctorius and Scots pine in vitro indicates that a low-cost by-product Fe–LS, obtained from paper industry, may be a potential tool to improve the efficiency of fungal inoculations, thus, facilitating the early interaction between an ECM fungus and host seedling.     

Three new species ofTrichogramma [Hymenoptera: Trichogrammatidae] from India

Three new species ofTrichogramma occurring in India are described. Two of these were reared from eggs of the sugarcane stem-borerChilotraea infuscatellus, while the third was found attacking eggs ofAchaea janata, Tiracola plagiata andHeliothis armigera. The diagnostic value of the male genitalia in this genus is emphasized and a discussion is presented justifying the consideration of these as new species.

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Résumé Trois nouvelles espèces deTrichogramma présentes en Inde sont décrites. Deux d'entre elles ont été obtenues d'œufs du foreur des tiges de la canne à sucre,Chilotraea infuscatellus, la troisième s'attaque aux œufs deAchaea janata, Tiracola plagiata etHeliothis armigera. La valeur pour la diagnose des genitalia males dans ce genre est soulignée et les arguments en faveur d'espèces nouvelles sont discutés.

     

Genetic population structure of the ectomycorrhizal fungus Pisolithus microcarpus suggests high gene flow in south-eastern Australia

Pisolithus are ectomycorrhizal fungi that associate with roots of numerous plant species in natural and plantation forests worldwide. Despite the fact that Pisolithus spp. are present in plantation forests in many countries, knowledge of the genetic population structure of Pisolithus spp. remains limited. In this study, we have tested the hypothesis that a propensity for long-distance spore dispersal in Pisolithus microcarpus, along with the widespread distribution of potential eucalypt and acacia plant hosts in south-eastern Australia facilitates gene flow that limits population differentiation. Five polymorphic simple sequence repeat markers were used to investigate the population structure of P. microcarpus. Isolates were grouped according to geographical origin and isolate genotypes were analysed among the geographical populations. Pairwise F _ST estimates indicated limited genetic differentiation among the geographical populations. Analysis of molecular variance revealed that most of the genetic variation present was within geographical populations, with only 1.3% of the genetic variation among P. microcarpus geographical populations. This was particularly pronounced for four geographical populations within a ca 7,000 km² area New South Wales, which were each separated by <100 km and appeared to be genetically homogeneous. The lack of population structure is suggested to be due to a high degree of gene flow, via basidiospores, between the New South Wales geographical populations.     

Intra-species genetic variability drives carbon metabolism and symbiotic host interactions in the ectomycorrhizal fungus Pisolithus microcarpus

Ectomycorrhizal (ECM) fungi are integral to boreal and temperate forest ecosystem functioning and nutrient cycling. ECM fungi, however, originate from diverse saprotrophic lineages and the impacts of genetic variation across species, and especially within a given ECM species, on function and interactions with the environment is not well understood. Here, we explore the extent of intra-species variation between four isolates of the ECM fungus Pisolithus microcarpus, in terms of gene regulation, carbon metabolism and growth, and interactions with a host, Eucalyptus grandis. We demonstrate that, while a core response to the host is maintained by all of the isolates tested, they have distinct patterns of gene expression and carbon metabolism, resulting in the differential expression of isolate-specific response pathways in the host plant. Together, these results highlight the importance of using a wider range of individuals within a species to understand the broader ecological roles of ECM fungi and their host interactions.     

Metabolism of 15N-labelled ammonium by the ectomycorrhizal fungus Pisolithus tinctorim (Pers.) Coker & Couch

Summary Glutamine was the major product accumulated following transfer of nitrogen-limited cultures of the ectomycorrhizal fungus Pisolithus tinctorius to an ammonium medium. Experiments in which mycelium was transferred to [¹⁵N]H ₄ ⁺ showed glutamine amide was the most heavily labelled product. Assimilation of ammonium into glutamate was markedly inhibited by azaserine. The kinetics of ¹⁵N-labelling and the effects of azaserine and methionine sulphoximine on the distribution of ¹⁵N-labelled products are entirely consistent with the operation of the glutamate synthase cycle. No evidence was found for ammonium assimilation via glutamate dehydrogenase. The labelling pattern observed in mycelium treated with aminooxyacetate suggests that transamination reactions are an important source of glutamate for the synthesis of glutamine.     

Profiling of differentially expressed genes in ectomycorrhizal fungus Pisolithus tinctorius responding to mycorrhiza helper Brevibacillus reuszeri MPt17

A cDNA library of the ectomycorrhizal (ECM) fungus Pisolithus tinctorius Pt2 after interaction with the mycorrhiza helper bacterium (MHB) Brevibacillus reuszeri MPt17 was constructed by suppression subtraction hybridization. Total RNA from B. reuszeri MPt17 exudates treated Pi. tinctorius Pt2 was used as a “tester” and total RNA from nonbacterial treated Pi. tinctorius Pt2 was used as a “driver.” Among the differentially expressed sequences, a BLASTX in the NCBI non-redundant protein sequence database revealed that 75% of the non-redundant sequences (147 out of 196) were highly similar to known proteins (E-value < e^?5). Twelve sequences were annotated as mycelium development function combining with a potential functional categories using gene ontology. Quantitative real-time PCR analysis showed that all of the 3 symbiosis regulated acidic polypeptide genes were all up-regulated in the MPt17-treated Pt2. These results provide evidence that the MHB B. reuszeri MPt17 could significantly change the expression of symbiosis-related genes and genes in mycelium development in ECM fungus, and also support the hypothesis that the MHB functions as helper though promotion on fungal mycelium.     

Chaenothecopsis quintralis, a new species of calicioid fungus

Chaenothecopsis quintralis from southwestern Argentina is described and illustrated as a new species in the family Mycocaliciaceae. It has been found in three localities in the Andean Patagonian temperate forests, growing strictly on dung of an endemic marsupial Dromiciops gliroides. The new species is distinguished by the hemispherical, black capitulum of ascoma, the presence of asci with croziers, one-celled brown ascospores, and its fimicolous habitat. Analysis of partial nuclear large subunit rDNA (LSU) sequences showed that this taxon is within Mycocaliciales.     

pTARGET [corrected] a new method for predicting protein subcellular localization in eukaryotes

MOTIVATION: There is a scarcity of efficient computational methods for predicting protein subcellular localization in eukaryotes. Currently available methods are inadequate for genome-scale predictions with several limitations. Here, we present a new prediction method, pTARGET that can predict proteins targeted to nine different subcellular locations in the eukaryotic animal species. RESULTS: The nine subcellular locations predicted by pTARGET include cytoplasm, endoplasmic reticulum, extracellular/secretory, golgi, lysosomes, mitochondria, nucleus, plasma membrane and peroxisomes. Predictions are based on the location-specific protein functional domains and the amino acid compositional differences across different subcellular locations. Overall, this method can predict 68-87% of the true positives at accuracy rates of 96-99%. Comparison of the prediction performance against PSORT showed that pTARGET prediction rates are higher by 11-60% in 6 of the 8 locations tested. Besides, the pTARGET method is robust enough for genome-scale prediction of protein subcellular localizations since, it does not rely on the presence of signal or target peptides. AVAILABILITY: A public web server based on the pTARGET method is accessible at the URL http://bioinformatics.albany.edu/~ptarget. Datasets used for developing pTARGET can be downloaded from this web server. Source code will be available on request from the corresponding author.     

Elaphomyces tropicalis sp. nov.: A new ectomycorrhizal fungus associated with dipterocarps from tropical Indonesia

A hypogeous, sequestrate, ectomycorrhizal fungus belonging to Elaphomyces was found in a Shorea plantation at Haurbentes Research Forest, West Java, Indonesia. Elaphomyces tropicalis is described as a new species based on morphological characters and molecular phylogenetic analysis of the ITS rDNA sequence. Sequences of E. tropicalis formed a distinct clade close to E. hassiacus, and sister to E. granulatus and E. asperulus. Elaphomyces tropicalis is not closely related to the E. papillatus clade. Morphologically, E. tropicalis is similar to E. (subsect Papillati) papillatus var. striatosporus with its crested spore ornamentation, but differs by having larger ascomata and different associated hosts. Shorea selanica and S. leprosula are the presumed hosts of E. tropicalis. This is the first report of an Elaphomyces species with Shorea species thus widening the previously known Elaphomyces host range.     

The Arabian scad Trachurus indicus, a new Indo-Pacific species in the Mediterranean Sea

The Arabian scad Trachurus indicus is recorded for the first time from the Mediterranean Sea (Iskenderun Bay, Turkey). The presence of this Indo-Pacific fish in the Mediterranean Sea is probably because of migration from the Red Sea via the Suez Canal.