Kobuvirus is a new genus in the family Picornaviridae. Two species are currently known: Aichi virus (human kobuvirus) and Bovine kobuvirus (U-1). In this study, the complete nucleotide and amino acid sequences and genetic organization of porcine kobuvirus (Kobuvirus/swine/S-1-HUN/2007/Hungary, EU787450) were determined. The structure of the S-1-HUN genome, VPg-5'UTR-leader protein-structural proteins (VP0, VP3, VP1)-non-structural proteins (2A-2C, 3A-3D)-3'UTR-poly(A) tail, was found to be typical of picornavirus. The 8210-nucleotide (nt)-long RNA genome contains a large open reading frame (7467 nt) encoding a potential polyprotein precursor of 2488 amino acids (aa) that has 57/56% and 63/64% nt/aa identity with Aichi virus and U-1, respectively. The 5'UTR contains a hepacivirus/pestivirus-like internal ribosomal entry site (IRES type IV group-B-like) with conserved pseudoknot, II and IIIa-f domains. A tandem repeat (a 30-amino-acid-long motif) was detected in 2B. Thirty-nine (65%) of the 60 fecal samples from pigs under the age of 6 months at the tested farm were positive (the incidence was 90% under the age of 3 weeks). Porcine kobuvirus belongs to a potential new species-the third-in the genus Kobuvirus.

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Aichi virus, genus Kobuvirus, family Picornaviridae, has been proposed as a causative agent of gastroenteritis in human. Although high seroprevalence has been detected, it has been identified in only a few cases. We report detection of Aichi virus in Hungary. A total of 65 stool samples were tested retrospectively, collected from children with diarrhea, by reverse transcription-polymerase chain reaction. One (1.5%) sample from a 3-year-old girl was positive. Besides diarrhea, fever, purulent conjunctivitis and respiratory symptoms were also present at the same time with virus shedding. The genotype A virus, Kobuvirus/human/Szigetvar-HUN298/2000/Hungary (FJ225407), has 96% nucleotide identity to Aichi virus.

The effects of various light intensities and spectral compositions on glutathione and amino acid metabolism were compared in wheat. Increase of light intensity (low—normal—high) was accompanied by a simultaneous increase in the shoot fresh weight, photosynthetic activity and glutathione content. These parameters were also affected by the modification of the ratios of blue, red and far-red components (referred to as blue, pink and far-red lights) compared to normal white light. The photosynthetic activity and the glutathione content decreased to 50% and the percentage of glutathione disulfide (characterising the redox state of the tissues) in the total glutathione pool doubled in far-red light. The alterations in the level and redox state of the antioxidant glutathione resulted from the effect of light on its synthesis as it could be concluded from the changes in the transcription of the related genes. Modification of the light conditions also greatly affected both the amount and the ratio of free amino acids. The total free amino acid content was greatly induced by the increase of light intensity and was greatly reduced in pink light compared to the normal intensity white light. The concentrations of most amino acids were similarly affected by the light conditions as described for the total free amino acid content but Pro, Met, Thr, ornithine and cystathionine showed unique response to light. As observed for the amino acid levels, the expression of several genes involved in their metabolism also enhanced due to increased light intensity. Interestingly, the modification of the spectrum greatly inhibited the expression of most of these genes. Correlation analysis of the investigated parameters indicates that changes in the light conditions may affect growth through the adjustment of photosynthesis and the glutathione-dependent redox state of the tissues. This process modifies the metabolism of glutathione and amino acids at transcriptional level.

CBF-regulon, barley, cereals, cold acclimation, freezing tolerance, light regulation, low red/far-red ratio, phytochrome, wheat.

CBF (C-repeat binding factor) transcription factors show high expression levels in response to cold; moreover, they play a key regulatory role in cold acclimation processes. Recently, however, more and more information has led to the conclusion that, apart from cold, light—including its spectra—also has a crucial role in regulating CBF expression. Earlier, studies established that the expression patterns of some of these regulatory genes follow circadian rhythms. To understand more of this complex acclimation process, we studied the expression patterns of the signal transducing pathways, including signal perception, the circadian clock and phospholipid signalling pathways, upstream of the CBF gene regulatory hub. To exclude the confounding effect of cold, experiments were carried out at 22 °C. Our results show that the expression of genes implicated in the phospholipid signalling pathway follow a circadian rhythm. We demonstrated that, from among the tested CBF genes expressed in Hordeum vulgare (Hv) under our conditions, only the members of the HvCBF4-phylogenetic subgroup showed a circadian pattern. We found that the HvCBF4-subgroup genes were expressed late in the afternoon or early in the night. We also determined the expression changes under supplemental far-red illumination and established that the transcript accumulation had appeared four hours earlier and more intensely in several cases. Based on our results, we propose a model to illustrate the effect of the circadian clock and the quality of the light on the elements of signalling pathways upstream of the HvCBFs, thus integrating the complex regulation of the early cellular responses, which finally lead to an elevated abiotic stress tolerance.

Wheat plants which are exposed to periods of low temperatures (cold acclimation) exhibit increased survival rates when they are subsequently exposed to freezing temperatures. This process is associated with large-scale changes in the transcriptome which are modulated by a set of tandemly duplicated CBF (C-repeat Binding Factor) transcription factors located at the Fr-2 (Frost Resistance-2) locus. While Arabidopsis has three tandemly duplicated CBF genes, the CBF family in wheat has undergone an expansion and at least 15 CBF genes have been identified, eleven of which are present at the Fr-2 loci on homoeologous group 5 chromosomes. We report here the discovery of three large deletions which eliminate six, nine, and all eleven CBF genes from the Fr-B2 locus in tetraploid and hexaploid wheat. In wild emmer wheat, the Fr-B2 deletions were found only among the accessions from the southern sub-populations. Among cultivated wheats, the Fr-B2 deletions were more common among varieties with a spring growth habit than among those with a winter growth habit. Replicated freezing tolerance experiments showed that both the deletion of nine CBF genes in tetraploid wheat and the complete Fr-B2 deletion in hexaploid wheat are associated with significant reductions in survival after exposure to freezing temperatures. Our results suggest that selection for the wild type Fr-B2 allele may be beneficial for breeders selecting for varieties with improved frost tolerance.

This study aimed to clarify whether the light condition-dependent changes in the redox state and subcellular distribution of glutathione were similar in the dicotyledonous model plant Arabidopsis (wild-type, ascorbate- and glutathione-deficient mutants) and the monocotyledonous crop species wheat (Chinese Spring variety). With increasing light intensity, the amount of its reduced (GSH) and oxidized (GSSG) form and the GSSG/GSH ratio increased in the leaf extracts of both species including all genotypes, while far-red light increased these parameters only in wheat except for GSH in the GSH-deficient Arabidopsis mutant. Based on the expression changes of the glutathione metabolism-related genes, light intensity influences the size and redox state of the glutathione pool at the transcriptional level in wheat but not in Arabidopsis. In line with the results in leaf extracts, a similar inducing effect of both light intensity and far-red light was found on the total glutathione content at the subcellular level in wheat. In contrast to the leaf extracts, the inducing influence of light intensity on glutathione level was only found in the cell compartments of the GSH-deficient Arabidopsis mutant, and far-red light increased it in both mutants. The observed general and genotype-specific, light-dependent changes in the accumulation and subcellular distribution of glutathione participate in adjusting the redox-dependent metabolism to the actual environmental conditions.