Search

A novel virus of the genus Narnavirus, designated "Saccharomyces narnavirus I329" (ScNV-I329), was discovered in Saccharomyces cerevisiae strain I-329, which is used for industrial production of sherry-like wines. The genome of ScNV-I329 is 2509 nt in length with short terminal inverted repeats and a single open reading frame capable of encoding an RNA-dependent RNA polymerase most closely related to that of Saccharomyces 20S RNA narnavirus. This is the third known member of the genus Narnavirus from yeasts. [ABSTRACT FROM AUTHOR]

Pinesap Monotropa hypopitys is a myco-heterotrophic non-photosynthetic higher angiosperm perennial plant devoid of vegetative organs and with standard flower arrangement. The MADS-domain transcription factor family has multiple regulatory functions in plant life cycle and is implicated in flower evolution and diversity. This study is the first to describe the MADS-box genes in a myco-heterotrophic eudicot. By performing the M. hypopitys transcriptome-wide analysis, we identified 30 MADS-box genes belonging to the major clades in the MIKCc and MIKC* lineages. Among them, MhyMADS18 is suggested as an ancestral gene of the cluster comprising AP1/FUL, FLC, SEP, and AGL6 clades. The RNA-seq profiling of the MhyMADS expression in the flowering plant revealed mRNAs specific to bracts, flowers, and roots with adventitious buds. Our results represent systematic and expression analysis of the pinesap MADS-box genes that may be involved in seed dormancy regulation, flowering time control, and flower organ identity specification. The obtained data should further our understanding of the roles played by the MADS-box genes in developmental regulation of myco-heterotrophic plants. [ABSTRACT FROM AUTHOR]

Monotropa hypopitys is a mycoheterotrophic, nonphotosynthetic plant acquiring nutrients from the roots of autotrophic trees through mycorrhizal symbiosis, and, similar to other extant plants, forming asymmetrical lateral organs during development. The members of the YABBY family of transcription factors are important players in the establishment of leaf and leaf-like organ polarity in plants. This is the first report on the identification of YABBY genes in a mycoheterotrophic plant devoid of aboveground vegetative organs. Seven M. hypopitys YABBY members were identified and classified into four clades. By structural analysis of putative encoded proteins, we confirmed the presence of YABBY-defining conserved domains and identified novel clade-specific motifs. Transcriptomic and qRT-PCR analyses of different tissues revealed MhyYABBY transcriptional patterns, which were similar to those of orthologous YABBY genes from other angiosperms. These data should contribute to the understanding of the role of the YABBY genes in the regulation of developmental and physiological processes in achlorophyllous leafless plants. [ABSTRACT FROM AUTHOR]

Microbial communities of four acidic thermal pools in the Uzon Caldera, Kamchatka, Russia, were studied using amplification and pyrosequencing of 16S rRNA gene fragments. The sites differed in temperature and pH: 1805 (60 °C, pH 3.7), 1810 (90 °C, pH 4.1), 1818 (80 °C, pH 3.5), and 1807 (86 °C, pH 5.6). Archaea of the order Sulfolobales were present among the dominant groups in all four pools. Acidilobales dominated in pool 1818 but were a minor fraction at the higher temperature in pool 1810. Uncultivated Archaea of the Hot Thaumarchaeota-related clade were present in significant quantities in pools 1805 and 1807, but they were not abundant in pools 1810 and 1818, where high temperatures were combined with low pH. Nanoarchaeota were present in all pools, but were more abundant in pools 1810 and 1818. A similar abundance pattern was observed for Halobacteriales. Thermophilic Bacteria were less diverse and were mostly represented by aerobic hydrogen- and sulfur-oxidizers of the phylum Aquificae and sulfur-oxidising Proteobacteria of the genus Acidithiobacillus. Thus we showed that extremely acidic hot pools contain diverse microbial communities comprising different metabolic groups of prokaryotes, including putative lithoautotrophs using energy sources of volcanic origin, and various facultative and obligate heterotrophs. [ABSTRACT FROM AUTHOR]

As a result of metagenomic analysis of feces of farm animals, 5 genomes of alpha-proteobacteria of the candidate genus Enterousia of the order Rs-D84 were assembled. The genomes ranged in size from 850 to 984 kb and contained from 835 to 961 protein-coding genes. Analysis of the genomes showed that these bacteria have fermentative metabolism and could produce lactate and acetate. Most of the genes for the Embden−Meyerhof glycolytic pathway and the non-oxidative phase of the pentose phosphate pathway are present, but the genes for glucokinase, glucose-6-phosphate isomerase and transaldolase were not found. Enterousia lack aerobic and anaerobic respiratory pathways, complete pathways for the amino acid, lipid and nucleotide biosynthesis, as well as secreted glycoside hydrolases and conventional transporters for the import of sugars and amino acids. Enterousia appear to have adopted the lifestyle of a symbiont/parasite or a scavenger obtaining metabolites from other cells or lysed biomass. Comparative genome analysis revealed that genome reduction is a common trait of the vast majority of other members of the candidate order Rs-D84. [ABSTRACT FROM AUTHOR]

Background: Chloroplasts of most plants are responsible for photosynthesis and contain a conserved set of about 110 genes that encode components of housekeeping gene expression machinery and photosynthesis-related functions. Heterotrophic plants obtaining nutrients from other organisms and their plastid genomes represent model systems in which to study the effects of relaxed selective pressure on photosynthetic function. The most evident is a reduction in the size and gene content of the plastome, which correlates with the loss of genes encoding photosynthetic machinery which become unnecessary. Transition to a non-photosynthetic lifestyle is expected also to relax the selective pressure on photosynthetic machinery in the nuclear genome, however, the corresponding changes are less known. Results: Here we report the complete sequence of the plastid genome of Monotropa hypopitys, an achlorophyllous obligately mycoheterotrophic plant belonging to the family Ericaceae. The plastome of M. hypopitys is greatly reduced in size (35,336 bp) and lacks the typical quadripartite structure with two single-copy regions and an inverted repeat. Only 45 genes remained presumably intact- those encoding ribosomal proteins, ribosomal and transfer RNA and housekeeping genes infA, matK, accD and clpP. The clpP and accD genes probably remain functional, although their sequences are highly diverged. The sets of genes for ribosomal protein and transfer RNA are incomplete relative to chloroplasts of a photosynthetic plant. Comparison of the plastid genomes of two subspecies-level isolates of M. hypopitys revealed major structural rearrangements associated with repeat-driven recombination and the presence of isolate-specific tRNA genes. Analysis of the M. hypopitys transcriptome by RNA-Seq showed the absence of expression of nuclear-encoded components of photosystem I and II reaction center proteins, components of cytochrome b6f complex, ATP synthase, ribulose bisphosphate carboxylase components, as well as chlorophyll from protoporphyrin IX biosynthesis pathway. Conclusions: With the complete loss of genes related to photosynthesis, NADH dehydrogenase, plastid-encoded RNA polymerase and ATP synthase, the M. hypopitys plastid genome is among the most functionally reduced ones characteristic of obligate non-photosynthetic parasitic species. Analysis of the M. hypopitys transcriptome revealed coordinated evolution of the nuclear and plastome genomes and the loss of photosynthesis-related functions in both genomes. [ABSTRACT FROM AUTHOR]

The corrected descriptions are as follows: Description of I Longinema gen. nov i . N.L. neut. n. I Longinema i , a bacterial genus; I -aceae i , ending to denote a family; N.L. fem. pl. n. I Longinemataceae i , the I Longinema i family). Targeted isolation based on metagenome-assembled genomes reveals a phylogenetically distinct group of thermophilic spirochetes from deep biosphere. [Extracted from the article]

Copyright of Stratum Plus Journal is the property of P.P. Stratum plus and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)