Roman A. Volkov

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To find evidence for a connection between heat stress response, oxidative stress, and common stress tolerance, we studied the effects of elevated growth temperatures and heat stress on the activity and expression of ascorbate peroxidase (APX). We compared wild-type Arabidopsis with transgenic plants overexpressing heat shock transcription factor 3 (HSF3),(More)
The nucleotide sequence of the intergenic spacer (IGS) region between the 25S and the 18S rRNA coding regions has been determined for tobacco (Nicotiana tabacum). The IGS (5140 bp in length) can be subdivided into several regions (I–VII) two of which, upstream and downstream of the putative transcription initiation site (TIS), contain prominent subrepeats(More)
The potential of different house-keeping genes for their use as internal standards of gene expression under changing environmental conditions and in different organs of plants was assessed. Using real-time PCR mRNA levels were precisely quantified for preselected actin and ribosomal protein genes in Arabidopsis thaliana (L.) Heinh. and Nicotiana tabacum L.(More)
In plants small heat shock proteins (sHsp) are abundantly expressed upon heat stress in vegetative tissue, however, sHsp expression is also developmentally induced in pollen. The developmental induction of sHsp has been related to the potential for stress-induced microspore embryogenesis. We investigated the polymorphism among sHsp and their expression(More)
Nucleotide sequences of 5S rRNA genes (5S rDNA) of 26 wild species of the genus Solanum (sect. Petota) originating from Middle or South America, four Solanum tuberosum breeding lines and one European species, Solanum dulcamara (sect. Dulcamara) were compared with each other and with the 5S rDNA of Lycopersicon esculentum. The length of the repeat ranges(More)
Oxygen-free radicals are thought to play an essential role in senescence. Therefore, the expression patterns of the small gene family encoding the H2O2 scavenging enzymes ascorbate peroxidase (APX; EC were analyzed during senescence of Arabidopsis thaliana (L.) Heinh. Applying real-time RT-PCR, the mRNA levels were quantified for three cytosolic(More)
The mechanisms of sensing and signalling of heat and oxidative stresses are not well understood. The central question of this paper is whether in plant cells oxidative stress, in particular H2O2, is required for heat stress- and heat shock factor (HSF)-dependent expression of genes. Heat stress increases intracellular accumulation of H2O2 in Arabidopsis(More)
The 5(') external transcribed spacer (ETS) region of ribosomal DNA of 30 species of Solanum sect. Petota and the European Solanum dulcamara were compared. Two structural elements can be distinguished in the ETS: (i). a variable region (VR), demonstrating significant structural rearrangements and (ii). a conservative region (CR), evolving mainly by base(More)
For two close diploid relatives of the allotetraploidNicotiana tabacum, N. sylvestris (subg.Petunioides) andN. tomentosiformis (subg.Nicotiana), the nucleotide sequences of the external transcribed rDNA spacer regions (ETS) are described and compared (within the genus and with otherSolanaceae). The ETS of these two diploid species consists of three regions:(More)
The complete nucleotide sequence (3701 bp) of the intergenic spacer region between the 3′-end of 25S rRNA gene and the 5′-end of 18S rRNA gene (IGS) is described forNicotiana sylvestris. The IGS ofN. sylvestris consists of seven structural regions (SR) two of which are composed of subrepeats (SR II: three and one half copies of the 76 bp D-subrepeat and(More)