Control of common scab disease can be reached by resistant cultivars or suppressive soils. Both mechanisms are likely to translate into particular potato microbiome profiles, but the relative importance of each is not known. Here, microbiomes of bulk and tuberosphere soil and of potato periderm were studied in one resistant and one susceptible cultivar grown in a conducive and a suppressive field. Disease severity was suppressed similarly by both means yet, the copy numbers of txtB gene (coding for a pathogenicity determinant) were similar in both soils but higher in periderms of the susceptible cultivar from conducive soil. Illumina sequencing of 16S rRNA genes for bacteria (completed by 16S rRNA microarray approach) and archaea, and of 18S rRNA genes for micro-eukarytes showed that in bacteria, the more important was the effect of cultivar and diversity decreased from resistant cultivar to bulk soil to susceptible cultivar. The major changes occurred in proportions of Actinobacteria, Chloroflexi, and Proteobacteria. In archaea and micro-eukaryotes, differences were primarily due to the suppressive and conducive soil. The effect of soil suppressiveness × cultivar resistance depended on the microbial community considered, but differed also with respect to soil and plant nutrient contents particularly in N, S and Fe.

• MeSH
• Actinobacteria klasifikace   genetika   růst a vývoj   patogenita   MeSH
• Archaea klasifikace   genetika   růst a vývoj   patogenita   MeSH
• Chloroflexi klasifikace   genetika   růst a vývoj   patogenita   MeSH
• dusík metabolismus   farmakologie   MeSH
• eukaryotické buňky metabolismus   MeSH
• faktory virulence genetika   metabolismus   MeSH
• genotypizační techniky MeSH
• mikrobiota genetika   MeSH
• náchylnost k nemoci imunologie   MeSH
• nemoci rostlin imunologie   mikrobiologie   MeSH
• odolnost vůči nemocem účinky léků   MeSH
• Proteobacteria klasifikace   genetika   růst a vývoj   patogenita   MeSH
• půdní mikrobiologie * MeSH
• RNA ribozomální 16S genetika   MeSH
• RNA ribozomální 18S genetika   MeSH
• síra metabolismus   farmakologie   MeSH
• Solanum tuberosum účinky léků   imunologie   mikrobiologie   MeSH
• železo metabolismus   farmakologie   MeSH
• zemědělské plodiny MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Present-day terrestrial analogue sites are crucial ground truth proxies for studying life in geochemical conditions close to those assumed to be present on early Earth or inferred to exist on other celestial bodies (e.g. Mars, Europa). Although hypersaline sapropels are border-of-life habitats with moderate occurrence, their microbiological and physicochemical characterization lags behind. Here, we study the diversity of life under low water activity by describing the prokaryotic communities from two disparate hypersaline sapropels (Transylvanian Basin, Romania) in relation to geochemical milieu and pore water chemistry, while inferring their role in carbon cycling by matching taxa to known taxon-specific biogeochemical functions. The polyphasic approach combined deep coverage SSU rRNA gene amplicon sequencing and bioinformatics with RT-qPCR and physicochemical investigations. We found that sapropels developed an analogous elemental milieu and harbored prokaryotes affiliated with fifty-nine phyla, among which the most abundant were Proteobacteria, Bacteroidetes and Chloroflexi. Containing thirty-two candidate divisions and possibly undocumented prokaryotic lineages, the hypersaline sapropels were found to accommodate one of the most diverse and novel ecosystems reported to date and may contribute to completing the phylogenetic branching of the tree of life.

• MeSH
• Archaea klasifikace   genetika   izolace a purifikace   MeSH
• Bacteroidetes genetika   izolace a purifikace   MeSH
• benzopyrany analýza   MeSH
• Chloroflexi genetika   izolace a purifikace   MeSH
• DNA bakterií genetika   MeSH
• fylogeneze MeSH
• geologické sedimenty mikrobiologie   MeSH
• huminové látky analýza   MeSH
• jezera mikrobiologie   MeSH
• Proteobacteria genetika   izolace a purifikace   MeSH
• ribozomální DNA genetika   MeSH
• sekvenční analýza DNA MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Geografické názvy
• Rumunsko MeSH

Light-harvesting capacity was investigated in six species of aerobic anoxygenic phototrophic (AAP) bacteria using absorption spectroscopy, fluorescence emission spectroscopy, and pigment analyses. Aerobically grown AAP cells contained approx. 140-1800 photosynthetic reaction centers per cell, an order of magnitude less than purple non-sulfur bacteria grown semiaerobically. Three of the studied AAP species did not contain outer light-harvesting complexes, and the size of their reaction center core complexes (RC-LH1 core complexes) varied between 29 and 36 bacteriochlorophyll molecules. In AAP species containing accessory antennae, the size was frequently reduced, providing between 5 and 60 additional bacteriochlorophyll molecules. In Roseobacter litoralis, it was found that cells grown at a higher light intensity contained more reaction centers per cell, while the size of the light-harvesting complexes was reduced. The presented results document that AAP species have both the reduced number and size of light-harvesting complexes which is consistent with the auxiliary role of phototrophy in this bacterial group.

• MeSH
• aerobióza MeSH
• Alphaproteobacteria chemie   metabolismus   MeSH
• bakteriochlorofyly metabolismus   MeSH
• fotosyntetické reakční centrum - proteinové komplexy chemie   metabolismus   MeSH
• fototrofní procesy MeSH
• Gammaproteobacteria chemie   metabolismus   MeSH
• světlosběrné proteinové komplexy chemie   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH