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The taxonomic position of an actinobacterium, designated CPCC 204380 T , which was isolated from a rhizosphere soil sample of the plant Calligonum mongolicum collected from Xinjiang Province, China, was established using a polyphasic approach. Vegetative hyphae developed well and globose bodies formed from aged hyphae. Spore chains that differentiated from the vegetative hyphae contained non-motile rod-shaped spores. The peptidoglycan contained meso-diaminopimelic acid and 3-hydroxydiaminopimelic acid as the diagnostic amino acids. The acyl type of the peptidoglycan was glycolyl. Glucose, mannose, ribose and xylose were detected in whole-cell hydrolysates. The predominant menaquinone was MK-10(H8), followed by MK-10(H6) and MK-10(H4). The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The major fatty acids were iso-C15 : 0, iso-C16 : 0 and C17 : 1ω9c. The genomic G+C content was 64.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CPCC 204380 T should be placed in the family Micromonosporaceae, in which it formed a distinct lineage next to the genera Rhizocola, Catellatospora, Catelliglobosispora, Hamadaea and Allocatelliglobosispora. It shared the highest 16S rRNA gene sequence similarities with Rhizocola hellebori K12-0602 T (96.1 %), Catellatospora chokoriensis 2-25/1 T (95.9 %), Catelliglobosispora koreensis DSM 44566 T (95.9 %), Hamadaea tsunoensis DSM 44101 T (95.3 %) and Allocatelliglobosispora scoriae Sco-B14 T (94.2 %), and less than 94.0 % sequence similarity with other validly described species. The combination of phylogenetic analysis and phenotypic characteristics supported the proposal of strain CPCC 204380 T as representing a novel species of a new genus in the family Micromonosporaceae, for which the name Allorhizocola rhizosphaerae gen. nov., sp. nov. is proposed. CPCC 204380 T (=DSM 102292 T =KCTC 39746 T ) is the type strain of the type species.

Ectomycorrhizal (ECM) fungi are important for efficient nutrient uptake of several widespread arctic plant species. Knowledge of temporal variation of ECM fungi, and the relationship of these patterns to environmental variables, is essential to understand energy and nutrient cycling in Arctic ecosystems. We sampled roots of Bistorta vivipara ten times over two years; three times during the growing-season (June, July and September) and twice during winter (November and April) of both years. We found 668 ECM OTUs belonging to 25 different ECM lineages, whereof 157 OTUs persisted throughout all sampling time-points. Overall, ECM fungal richness peaked in winter and species belonging to Cortinarius, Serendipita and Sebacina were more frequent in winter than during summer. Structure of ECM fungal communities was primarily affected by spatial factors. However, after accounting for spatial effects, significant seasonal variation was evident revealing correspondence with seasonal changes in environmental conditions. We demonstrate that arctic ECM richness and community structure differ between summer (growing-season) and winter, possibly due to reduced activity of the core community, and addition of fungi adapted for winter conditions forming a winter-active fungal community. Significant month × year interactions were observed both for fungal richness and community composition, indicating unpredictable between-year variation. Our study indicates that addressing seasonal changes requires replication over several years., (© 2015 John Wiley & Sons Ltd.)

There is growing evidence that root-associated fungi have important roles in Arctic ecosystems. Here, we assess the diversity of fungal communities associated with roots of the ectomycorrhizal perennial herb Bistorta vivipara on the Arctic archipelago of Svalbard and investigate whether spatial separation and bioclimatic variation are important structuring factors of fungal community composition. We sampled 160 plants of B. vivipara from 32 localities across Svalbard. DNA was extracted from entire root systems, and 454 pyrosequencing of ITS1 amplicons was used to profile the fungal communities. The fungal communities were predominantly composed of Basidiomycota (55% of reads) and Ascomycota (35%), with the orders Thelephorales (24%), Agaricales (13.8%), Pezizales (12.6%) and Sebacinales (11.3%) accounting for most of the reads. Plants from the same site or region had more similar fungal communities to one another than plants from other sites or regions, and sites clustered together along a weak latitudinal gradient. Furthermore, a decrease in per-plant OTU richness with increasing latitude was observed. However, no statistically significant spatial autocorrelation between sites was detected, suggesting that environmental filtering, not dispersal limitation, causes the observed patterns. Our analyses suggest that while latitudinal patterns in community composition and richness might reflect bioclimatic influences at global spatial scales, at the smaller spatial scale of the Svalbard archipelago, these changes more likely reflect varied bedrock composition and associated edaphic factors. The need for further studies focusing on identifying those specific bioclimatic and edaphic factors structuring root-associated fungal community composition at both global and local scales is emphasized., (© 2013 John Wiley & Sons Ltd.)

The main gradient in vascular plant, bryophyte and lichen species composition in alpine areas, structured by the topographic gradient from wind-exposed ridges to snowbeds, has been extensively studied. Tolerance to environmental stress, resulting from wind abrasion and desiccation towards windswept ridges or reduced growing season due to prolonged snow cover towards snowbeds, is an important ecological mechanism in this gradient. The extent to which belowground fungal communities are structured by the same topographic gradient and the eventual mechanisms involved are less well known. In this study, we analysed variation in fungal diversity and community composition associated with roots of the ectomycorrhizal plant Bistorta vivipara along the ridge-to-snowbed gradient. We collected root samples from fifty B. vivipara plants in ten plots in an alpine area in central Norway. The fungal communities were analysed using 454 pyrosequencing analyses of tag-encoded ITS1 amplicons. A distinct gradient in the fungal community composition was found that coincided with variation from ridge to snowbeds. This gradient was paralleled by change in soil content of carbon, nitrogen and phosphorus. A large proportion (66%) of the detected 801 nonsingleton operational taxonomic units (OTUs) were ascomycetes, while basidiomycetes dominated quantitatively (i.e. with respect to number of reads). Numerous fungal OTUs, many with taxonomic affinity to Sebacinales, Cortinarius and Meliniomyces, showed distinct affinities either to ridge or to snowbed plots, indicating habitat specialization. The compositional turnover of fungal communities along the gradient was not paralleled by a gradient in species richness., (© 2013 John Wiley & Sons Ltd.)

In this study, the identity and distribution of plants and the structure of their associated rhizobacterial communities were examined in an oil-contaminated site. The number of plant species that formed a community or were scattered was 24. The species living in soil highly contaminated with total petroleum hydrocarbon (TPH) (9,000-4,5000 mg/g-soil) were Cynodon dactylon, Persicaria lapathifolia, and Calystegia soldanella (a halophytic species). Among the 24 plant species, the following have been known to be effective for oil removal: C. dactylon, Digitaria sanguinalis, and Cyperus orthostachyus. Denaturing gradient gel electrophoresis (DGGE) profile analysis showed that the following pairs of plant species had highly similar (above 70%) rhizobacterial community structures: Artemisia princeps and Hemistepta lyrata; C. dactylon and P. lapathifolia; Carex kobomugi and Cardamine flexuosa; and Equisetum arvense and D. sanguinalis. The major groups of rhizobacteria were Betaproteobacteria, Gamma-proteobacteria, Chloroflexi, Actinobacteria, and unknown. Based on DGGE analysis, P. lapathifolia, found for the first time in this study growing in the presence of high TPH, may be a good species for phytoremediation of oil-contaminated soils and in particular, C. soldanella may be useful for soils with high TPH and salt concentrations. Overall, this study suggests that the plant roots, regardless of plant species, may have a similar influence on the bacterial community structure in oil-contaminated soil.