Karel Müller

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In angiosperms, mitochondrial-encoded genes can cause cytoplasmic male sterility (CMS), resulting in the coexistence of female and hermaphroditic individuals (gynodioecy). We compared four complete mitochondrial genomes from the gynodioecious species Silene vulgaris and found unprecedented amounts of intraspecific diversity for plant mitochondrial DNA(More)
We studied the effect of biotic stress caused by Potato virus Y (PVY) on photosynthesis in transgenic Pssu-ipt tobacco overproducing endogenous cytokinins (CK) in comparison with control (non-transformed) plants. Both control and transgenic tobacco were grown as rooted or grafted plants. Content of viral protein increased significantly in control tobacco(More)
The effect of biotic stress induced by viral infection (Potato virus Y, strain NTN and O) on NADP-malic enzyme (EC in tobacco plants (Nicotiana tabacum L., cv. Petit Havana, SR1) was tested at the transcriptional, translational and activity level. The increase of enzyme activity in infected leaves was correlated with the increased amount of(More)
Although rapid changes in copy number and gene order are common within plant mitochondrial genomes, associated patterns of gene transcription are underinvestigated. Previous studies have shown that the gynodioecious plant species Silene vulgaris exhibits high mitochondrial diversity and occasional paternal inheritance of mitochondrial markers. Here we(More)
The effect of viral infection on the regulation of phosphoenolpyruvate carboxylase (PEPC, EC in Nicotiana tabacum L. leaves was studied. PEPC activity was 3 times higher in infected plant leaves compared to healthy plants. Activity of plant PEPC can be regulated, e.g., by de novo synthesis or reversible phosphorylation. The reason for the increase(More)
Phosphoenolpyruvate carboxylase (PEPC, EC from mature maize seeds (Zea mays L.) was purified to homogeneity and a final specific activity of 13.3 μmol min⁻¹ mg⁻¹. Purified PEPC was treated with phosphatase from bovine intestinal mucosa or protein kinase A to study its apparent phosphorylation level. Kinetic parameters of the enzyme reaction(More)
An extraordinary variation in mitochondrial DNA sequence exists in angiosperm Silene vulgaris. The atp1 gene is flanked by very variable regions, as deduced from four completely sequenced mitochondrial genomes of this species. This diversity contributed to a highly variable transcript profile of this gene observed across S. vulgaris populations. We examined(More)
Chimeric genes are significant sources of evolutionary innovation that are normally created when portions of two or more protein coding regions fuse to form a new open reading frame. In plant mitochondria astonishingly high numbers of different novel chimeric genes have been reported, where they are generated through processes of rearrangement and(More)
Faster or stronger response to pathogen occurs if plants undergo prior priming. Cytokinins seem to be also involved in plant priming and in response to pathogens. Susceptibility to Potato virus Y(NTN) (PVY(NTN)) was studied in transgenic cytokinin overproducing (Pssu-ipt) tobacco and compared with nontransgenic plants. Since cytokinin overproduction(More)