TAS3 miR390-dependent loci in non-vascular land plants: towards a comprehensive reconstruction of the gene evolutionary history.

Trans-acting small interfering RNAs (ta-siRNAs) are transcribed from protein non-coding genomic TAS loci and belong to a plant-specific class of endogenous small RNAs. These siRNAs have been found to regulate gene expression in most taxa including seed plants, gymnosperms, ferns and mosses. In this study, bioinformatic and experimental PCR-based approaches were used as tools to analyze TAS3 and TAS6 loci in transcriptomes and genomic DNAs from representatives of evolutionary distant non-vascular plant taxa such as Bryophyta, Marchantiophyta and Anthocerotophyta.

Phylogeny of the plant 4/1 proteins.

The Nt-4/1 protein of unknown function has been shown to be alpha-helical and predominantly expressed in conductive tissues of tobacco plants. So far, obvious Nt-4/1 orthologs were found only in flowering plants. We report the analysis of 4/1 genes and the encoded proteins of lower land plants (Morozov et al.

Structural evolution of the 4/1 genes and proteins in non-vascular and lower vascular plants.

The 4/1 protein of unknown function is encoded by a single-copy gene in most higher plants. The 4/1 protein of Nicotiana tabacum (Nt-4/1 protein) has been shown to be alpha-helical and predominantly expressed in conductive tissues. Here, we report the analysis of 4/1 genes and the encoded proteins of lower land plants.

Peculiar evolutionary history of miR390-guided TAS3-like genes in land plants.

PCR-based approach was used as a phylogenetic profiling tool to probe genomic DNA samples from representatives of evolutionary distant moss taxa, namely, classes Bryopsida, Tetraphidopsida, Polytrichopsida, Andreaeopsida, and Sphagnopsida. We found relatives of all Physcomitrella patens miR390 and TAS3-like loci in these plant taxa excluding Sphagnopsida. Importantly, cloning and sequencing of Marchantia polymorpha genomic DNA showed miR390 and TAS3-like sequences which were also found among genomic reads of M.

Intragenomic heterogeneity of the 16S rRNA-23S rRNA internal transcribed spacer among Pseudomonas syringae and Pseudomonas fluorescens strains.

The 16S-23S rRNA internal transcribed spacer regions (ITS1) from 14 strains of Pseudomonas syringae and P. fluorescens were sequenced. ITS1 exhibited significant sequence variability among different operons within a single genome.