Stress reactions of Scots pine trees to injuring by ground fire

Controlled burning has been carried out to stimulate moderate ground fire in the Scots pine (Pinus sуlvestris L.) stand (age class I) in the Krasnoyarsk forest steppe at the beginning of the growing season. The structure of annual rings and trophic supply, as well as the cambial zone antioxidant system condition and the content of photosynthetic pigments in the needles of dominant and suppressed trees in the experimental and control plots, were studied 3 h, 5 days, and 2.5 months after the fire. The fire narrowed the annual ring width, since the number and size of early and late tracheids decreased. The primary reaction to pyrogenic heat shock (sharp reduction of chlorophyll content in needles and manifestation of oxidative stress in the stem cambial zone) was an elevated level of hydrogen peroxide and activity of most antioxidant enzymes and a reduction in the nonstructural carbohydrates pool. Restoration of the cambium function after the fire was promoted by an increased activity of amylase, invertase, and peroxidase.     

Density functional calculations of 15N chemical shifts in solvated dipeptides

We performed density functional calculations to examine the effects of solvation, hydrogen bonding, backbone conformation, and the side chain on 15N chemical shielding in proteins. We used N-methylacetamide (NMA) and N-formyl-alanyl-X (with X being one of the 19 naturally occurring amino acids excluding proline) as model systems. In addition, calculations were performed for selected fragments from protein GB3. The conducting polarizable continuum model was employed to include the effect of solvent in the density functional calculations. Our calculations for NMA show that the augmentation of the polarizable continuum model with the explicit water molecules in the first solvation shell has a significant influence on isotropic 15N chemical shift but not as much on the chemical shift anisotropy. The difference in the isotropic chemical shift between the standard beta-sheet and alpha-helical conformations ranges from 0.8 to 6.2 ppm depending on the residue type, with the mean of 2.7 ppm. This is in good agreement with the experimental chemical shifts averaged over a database of 36 proteins containing >6100 amino acid residues. The orientation of the 15N chemical shielding tensor as well as its anisotropy and asymmetry are also in the range of values experimentally observed for peptides and proteins.     

Plant proteome changes under abiotic stress--contribution of proteomics studies to understanding plant stress response

Plant acclimation to stress is associated with profound changes in proteome composition. Since proteins are directly involved in plant stress response, proteomics studies can significantly contribute to unravel the possible relationships between protein abundance and plant stress acclimation. In this review, proteomics studies dealing with plant response to a broad range of abiotic stress factors--cold, heat, drought, waterlogging, salinity, ozone treatment, hypoxia and anoxia, herbicide treatments, inadequate or excessive light conditions, disbalances in mineral nutrition, enhanced concentrations of heavy metals, radioactivity and mechanical wounding are discussed. Most studies have been carried out on model plants Arabidopsis thaliana and rice due to large protein sequence databases available; however, the variety of plant species used for proteomics analyses is rapidly increasing. Protein response pathways shared by different plant species under various stress conditions (glycolytic pathway, enzymes of ascorbate-glutathione cycle, accumulation of LEA proteins) as well as pathways unique to a given stress are discussed. Results from proteomics studies are interpreted with respect to physiological factors determining plant stress response. In conclusion, examples of application of proteomics studies in search for protein markers underlying phenotypic variation in physiological parameters associated with plant stress tolerance are given.     

Analysis of proteome and frost tolerance in chromosome 5A and 5B reciprocal substitution lines between two winter wheats during long-term cold acclimation

Dynamics of cold tolerance and crown proteome composition has been analysed in a set of two winter wheat cultivars Mironovskaya 808 and Bezostaya 1 and four reciprocal substitution lines with interchanged chromosomes 5A and 5B during a long-term cold-acclimation (CA) treatment. Proteome analysis has revealed 298 differently abundant spots during experiment. Most of them (260) were changed due to CA process and only 52 spots displayed differences between genotypes. Two hundred and seven protein spots were successfully identified by tandem mass spectrometry. Comparison of samples before and after vernalization fulfillment by a combination of ANOVA and Student' T-test displayed ten differentially abundant protein spots (e.g. chopper chaperones). However, differences in the accumulation of these spots did not reflect differences in vernalization requirement of genotypes. Therefore, our results indicate that vernalization process has not influenced total proteome of CA wheat crowns. A few protein spots (14 spots; e.g. malate dehydrogenase) revealed differential accumulation levels between the individual genotypes or their groups possessing chromosome 5A or 5B from Mironovskaya 808 versus Bezostaya 1. The study has shown the effect of chromosome 5A on physiological traits and also proteome in winter wheat. Putative candidate protein markers for cold tolerance in wheat are discussed.     

Moclobemide and cognitive behavioral therapy in the treatment of social phobia. A six-month controlled study and 24 months follow up

The aim of the study was to assess the 6-months treatment efficacy and 24-month follow up of three different therapeutic programs (A. moclobemide and supportive guidance, B. group cognitive-behavioral therapy and pill placebo, and C. combination of moclobemide and group cognitive-behavioral therapy) in patients with a generalized form of social phobia. Eighty one patients (38 males and 43 females) were randomly assigned to three different therapeutic programs. Patients were regularly assessed on a monthly basis by an independent rater on the LSAS (Liebowitz Social Anxiety scale), CGI (Clinical Global Impression) for severity and change and BAI (Beck Anxiety Inventory). Altogether, sixty-six patients completed the six month treatment period and 15 patients dropped out. All therapeutic groups showed significant improvement. A combination of CBT and pharmacotherapy yielded the most rapid effect. Moclobemide was superior for the reduction of the subjective general anxiety (BAI) during the first 3 months of treatment, but its influence on avoidant behavior (LSAS avoidance subscale) was less pronounced. Conversely, CBT was the best choice for reduction of avoidant behavior while a reduction of subjective general anxiety appeared later than in moclobemide. After 6 months of treatment there were best results reached in groups treated with CBT and there was no advantage of the combined treatment. The relapse rate during the 24-month follow up was significantly lower in the group treated with CBT in comparison with the group A. formerly treated with moclobemide alone.     

Effect of thermal radiation of forest fire on the environment

Thermal radiation of forest fires of different kinds was studied. Areas have been established where thermal radiation affects the forest stands and firemen.     

Density functional calculations of chemical shielding of backbone <Superscript>15</Superscript>N in helical residues of protein G

We performed density functional calculations of backbone ¹⁵N chemical shielding tensors in selected helical residues of protein G. Here we describe a computationally efficient methodology to include most of the important effects in the calculation of chemical shieldings of backbone ¹⁵N. We analyzed the role of long-range intra-protein electrostatic interactions by comparing models with different complexity in vacuum and in charge field. Our results show that the dipole moment of the α-helix can cause significant deshielding of ¹⁵N; therefore, it needs to be considered when calculating ¹⁵N chemical shielding. We found that it is important to include interactions with the side chains that are close in space when the charged form for ionizable side chains is adopted in the calculation. We also illustrate how the ionization state of these side chains can affect the chemical shielding tensor elements. Chemical shielding calculations using a 8-residue fragment model in vacuum and adopting the charged form of ionizable side chains yield a generally good agreement with experimental data.