The saprotrophic wood-degrading abilities of Rigidoporus microporus

Saprotrophic wood-decaying abilities ofRigidoporus microporus (Polyporales, Basidiomycota) syn. Rigidoporus lignosus and the structural alterations induced in wood blocks of Hevea bra-siliensis Muell. Arg were studied. Mass loss of wood blocks was analyzed after 3 and 6 months respectively and the patterns of decay by pathogenic and endophytic isolates of this fungus were investigated using light microscopy. Effects of temperature on growth of the isolates on malt extract agar were also investigated. The R. microporus isolated from a non-H. brasiliensis host caused the highest percentage mass loss (27.2% after 6 months), followed by isolates ED310 (21.1%) and M13 (15.7%), both collected from diseased H. brasiliensis plantations. The isolate initially identified as an endophyte showed very low saprotrophic wood decay capability (4.3% after 6 months). The optimal temperature for growth of the isolates was 30 °C; except for the endophytic isolate which showed highest growth at 25 °C. Wood samples degraded by the R. microporus isolates showed simultaneous attack of wood cell walls, typical of white rot fungi. Results of the study indicate variability in the wood degrading abilities of the isolates and the potential differences in their physiology are discussed. Our findings further support the need for a taxonomical revision of the Rigidoporus genus

Особливості трудового виховання і профорієнтації в умовах нової парадигми освіти

(uk) У статті розкривається проблема формування майбутнього учителя-предметника, готового до забезпечення трудового виховання у професійній діяльності у світлі нової освітньої парадигми

Transcriptional analysis of Pinus sylvestris roots challenged with the ectomycorrhizal fungus Laccaria bicolor

Peer reviewe

Secret lifestyles of Neurospora crassa

Peer reviewe

Transcriptional Responses Associated with Virulence and Defence in the Interaction between Heterobasidion annosum s. s. and Norway Spruce

Heterobasidion annosum sensu lato is a serious pathogen causing root and stem rot to conifers in the northern hemisphere and rendering the timber defective for sawing and pulping. In this study we applied next-generation sequencing to i) identify transcriptional responses unique to Heterobasidion-inoculated Norway spruce and ii) investigate the H. annosum transcripts to identify putative virulence factors. To address these objectives we wounded or inoculated 30-year-old Norway spruce clones with H. annosumand 454-sequenced the transcriptome of the interaction at 0, 5 and 15 days post inoculation. The 491860 high-quality reads were de novo assembled and the relative expression was analysed. Overall, very few H. annosum transcripts were represented in our dataset. Three delta-12 fatty acid desaturase transcripts and one Clavaminate synthase-like transcript, both associated with virulence in other pathosystems, were found among the significantly induced transcripts. The analysis of the Norway spruce transcriptional responses produced a handful of differentially expressed transcripts. Most of these transcripts originated from genes known to respond to H. annosum. However, three genes that had not previously been reported to respond to H. annosum showed specific induction to inoculation: an oxophytodienoic acid-reductase (OPR), a beta-glucosidaseand a germin-like protein (GLP2) gene. Even in a small data set like ours, five novel highly expressed Norway spruce transcripts without significant alignment to any previously annotated protein in Genbank but present in the P. abies (v1.0) gene catalogue were identified. Their expression pattern suggests a role in defence. Therefore a more complete survey of the transcriptional responses in the interactions between Norway spruce and its major pathogen H. annosumwould probably provide a better understanding of gymnosperm defence than accumulated until now.Peer reviewe

Expression analysis of Clavata1-like and Nodulin21-like genes from Pinus sylvestris during ectomycorrhiza formation

The ecology and physiology of ectomycorrhizal (EcM) symbiosis with conifer trees are well documented. In comparison, however, very little is known about the molecular regulation of these associations. In an earlier study, we identified three EcM-regulated Pinus expressed sequence tags (EST), two of which were identified as homologous to the Medicago truncatula nodulin MtN21. The third EST was a homologue to the receptor-like kinase Clavata1. We have characterized the expression patterns of these genes and of auxin- and mycorrhiza-regulated genes after induction with indole-3-butyric acid in Pinus sylvestris and in a time course experiment during ectomycorrhizal initiation with the co-inoculation of 2,3,5-triiodobenzoic acid, an auxin transport inhibitor. Our results suggest that different P. sylvestris nodulin homologues are associated with diverse processes in the root. The results also suggest a potential role of the Clv1-like gene in lateral root initiation by the ectomycorrhizal fungus

Expression and beta-glucan binding properties of Scots pine (Pinus sylvestris L.) antimicrobial protein (Sp-AMP)

Scots pine (Pinus sylvestris) secretes a number of small, highly-related, disulfide-rich proteins (Sp-AMPs) in response to challenges with fungal pathogens such as Heterobasidion annosum, although their biological role has been unknown. Here, we examined the expression patterns of these genes, as well as the structure and function of the encoded proteins. Northern blots and quantitative real time PCR showed increased levels of expression that are sustained during the interactions of host trees with pathogens, but not non-pathogens, consistent with a function in conifer tree defenses. Furthermore, the genes were up-regulated after treatment with salicylic acid and an ethylene precursor, 1-aminocyclopropane-1-carboxylic-acid, but neither methyl jasmonate nor H(2)O(2) induced expression, indicating that Sp-AMP gene expression is independent of the jasmonic acid signaling pathways. The cDNA encoding one of the proteins was cloned and expressed in Pichia pastoris. The purified protein had antifungal activity against H. annosum, and caused morphological changes in its hyphae and spores. It was directly shown to bind soluble and insoluble beta-(1,3)-glucans, specifically and with high affinity. Furthermore, addition of exogenous glucan is linked to higher levels of Sp-AMP expression in the conifer. Homology modeling and sequence comparisons suggest that a conserved patch on the surface of the globular Sp-AMP is a carbohydrate-binding site that can accommodate approximately four sugar units. We conclude that these proteins belong to a new family of antimicrobial proteins (PR-19) that are likely to act by binding the glucans that are a major component of fungal cell walls

Differentially expressed transcripts in inoculation and wounding treatment relative to the control at different time points.

<p>A Venn diagram showing the differentially expressed genes (<i>P</i>-value <0.05 after FDR [Benjamini-Hochberg procedure]) at 5 dpi inoculation with <i>H</i>. <i>annosum</i> (green) or wounding (yellow) and 15 dpi inoculation with <i>H</i>. <i>annosum</i> (red) or wounding (blue).</p

Annotation statistics of the assembled transcripts.

<p>^# Total number of isotigs (putative splice variants of genes) assembled with Newbler 2.6.</p><p>^§ Isotigs annotated with Blast2GO [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0131182#pone.0131182.ref018" target="_blank">18</a>]</p><p>^† Taxonomic assignation with MEGAN4 [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0131182#pone.0131182.ref019" target="_blank">19</a>]</p><p>^¥ Isotigs with best hit to <i>Picea sitchensis</i> proteins in Genbank</p><p>*Reciprocal best blastn hit with the <i>P</i>. <i>abies</i> 1.0 transcript database [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0131182#pone.0131182.ref027" target="_blank">27</a>]</p><p>^¤ Isotigs without a significant hit in the <i>P</i>. <i>abies</i> 1.0 transcript database, and of these likely <i>Pinaceae</i> and fungal genes are reported.</p><p>Annotation statistics of the assembled transcripts.</p