Spatio-temporal localization of selected pectic and arabinogalactan protein epitopes and the ultrastructural characteristics of explant cells that accompany the changes in the cell fate during somatic embryogenesis in Arabidopsis thaliana

During somatic embryogenesis (SE), explant cells undergo changes in the direction of their differentiation, which lead to diverse cell phenotypes. Although the genetic bases of the SE have been extensively studied in Arabidopsis thaliana, little is known about the chemical characteristics of the wall of the explant cells, which undergo changes in the direction of differentiation. Thus, we examined the occurrence of selected pectic and AGP epitopes in explant cells that display different phenotypes during SE. Explants examinations have been supplemented with an analysis of the ultrastructure. The deposition of selected pectic and AGP epitopes in somatic embryos was determined. Compared to an explant at the initial stage, a/embryogenic/totipotent and meristematic/pluripotent cells were characterized by a decrease in the presence of AGP epitopes, b/the presence of AGP epitopes in differentiated cells was similar, and c/an increase of analyzed epitopes was detected in the callus cells. Totipotent cells could be distinguished from pluripotent cells by: 1/the presence of the LM2 epitope in the latest one, 2/the appearance of the JIM16 epitope in totipotent cells, and 3/the more abundant presence of the JIM7 epitope in the totipotent cells. The LM5 epitope characterized the wall of the cells that were localized within the mass of embryogenic domain. The JIM8, JIM13 and JIM16 AGP epitopes appeared to be the most specific for the callus cells. The results indicate a relationship between the developmental state of the explant cells and the chemical composition of the cell walls

Skuteczność szkoleń kwalifikacyjnych jako metody aktywizacji zawodowej a płeć : na przykładzie absolwentów szkoleń przekwalifikowujących programów pomocowych Unii Europejskiej PHARE Inicjatywa I (PL 9811) i PHARE Inicjatywa II

W niniejszym artykule zaprezentowano wyniki badań absolwentów szkoleń przekwalifikowujących prowadzonych w ramach programów po-mocowych Unii Europejskiej Inicjatywa I (PL 9811) i Inicjatywa II, ze szcze-gólnym uwzględnieniem różnic między kobietami i mężczyznami. Badania były realizowane w okresie od czerwca do września 2002 roku W listopadzie 1999 roku rozpoczęła się realizacja programu pomocowe-go Unii Europejskiej PHARE Inicjatywa I (PL 9811) pierwszego i największego tego typu programu przeprowadzanego dotąd w Polsce. Beneficjentami programu byli pracownicy sektora górniczego zagrożeni utratą pracy. W ramach programu przeszkolono 1868 uprawnionych do tego pracowników zakładów wydobywczych. W związku z dużym zainteresowaniem szkoleniami i wskutek wyczerpania budżetu Inicjatywy PL 9811, w styczniu 2001 roku zostały uruchomione dodatkowe środki finansowe Unii Europejskiej na realizację programu PL 9903.01 Inicjatywa II pt. Przekwalifikowujące szkolenia zawodowe dla zwalnianych i zwalniających się pracowników sektora górnictwa węgla kamiennego w Polsce. Szkoleniami objęto dodatkowo byłych pracowników kopalń, którzy po odejściu z górnictwa nie znaleźli nowego miejsca zatrudnienia. Łącznie z obydwu programów skorzystało ponad 4100 osób. Celem programów było wsparcie rządowego programu restrukturyzacji górnictwa węgla kamiennego przez łagodzenie społecznych i regionalnych skutków wynikających z całkowitej lub częściowej redukcji zatrudnienia. Szkolenia miały przyczynić się do uzyskania przez zwalnianych pracowników sektora górnictwa węgla kamiennego zawodu (kwalifikacji) umożliwiającego im znalezienie pracy poza sektorem

Orientational variability of parallel arrays of cortical microtubules under the outer cell wall of the helianthus hypocotyl epidermis

The epidermis of Helianthus hypocotyl can be peeled off and, in the form of detached strips can be used as a model system to study the effect on cortical microtubule (cMTs) orientation of these factors, which are difficult to be manipulated in situ, such as apoplastic pH or applied stress. In the first step, however, the orientation and reorientation of cMTs in the epidermis in situ must be described. The cMTs under the epidermal wall in hypocotyl epidermis at different positions along the hypocotyl and on its opposite sides were studied by means of immunostaining, using epi-fluorescence microscopy. The angle l that parallel array of cMTs makes with cell longitudinal axis was measured. The variation of l in a population of cells was documented by l-histogram (frequency of cells exhibiting a particular l±Dl plotted against l value). The histograms were of either transverse type (maximum at l ~90°, denoted as type A) or oblique type (two maxima on both sides of the transverse direction, denoted as type B) in the apical part of the hypocotyl, and were either of B type or of longitudinal type (maximum at l ~0° or 180° denoted as type C) in the basal part. The change from A or B to C basipetally may be considered as due to the developmental trend in cMT orientation. The occurrence of B above A in some hypocotyls in their apical part strengthens the hypothesis on the autonomous reorientation of cMTs. The intermingled occurrence of Aand B reorientation in the upper part of hypocotyl is interpreted as amanifestation of a subtle control of cell growth in latitudinal direction. The majority of histograms were asymmetric showing predominance of cMT parallel arrays inclined as the middle part of the letter Z

Histological analysis reveals the formation of shoots rather than embryos in regenerating cultures of Eucalyptus globulus

Eucalyptus globulus is an important species in international forestry in regions with Mediterranean climates and comprises 65 % of the plantation hardwood in Australia. Propagation by somatic embryogenesis would offer many advantages and its development has received much attention. Structures regenerating on explants from hypocotyls of mature zygotic embryos of E. globulus cultured on medium with NAA, reported previously to be effective for embryogenic regeneration, were analyzed morphologically and histologically to clarify their pathway of development. Analysis of series of sections revealed organogenic, rather than embryogenic, pathways of regeneration in this system. We show that protocols for propagation of E. globulus must be carefully evaluated by microscopic examination of adequate numbers of serial sections

Red Fox Vulpes vulpes (L., 1758) as a Bioindicator of Mercury Contamination in Terrestrial Ecosystems of North-Western Poland

In this study, we determined the concentrations of total mercury (Hg) in samples of liver, kidney and skeletal muscle of 27 red foxes Vulpes vulpes (L., 1758) from north-western Poland, and examined the morphometric characteristics of the collected specimens. The analysis also included the relationship between Hg concentration and the fox size, and the suitability of individual organs as bioindicators in indirect evaluation of environmental mercury contamination. Determination of Hg concentration was performed by atomic absorption spectroscopy. In the analysed samples, the Hg concentration was low and the maximum value did not exceed 0.85 mgHg/kg dry weight (dw). There were no significant differences in Hg concentrations in the analysed material between males and females or between immature and adult groups. The median concentrations of Hg in the liver, kidney and skeletal muscle were 0.22, 0.11 and 0.05 mgHg/kg dw, respectively. The correlation coefficients were significant between the concentrations of mercury in the liver, kidney and skeletal muscle (positive) and between the kidney Hg concentration and kidney mass (negative). Taking into account our results and findings of other authors, it may be argued that the red fox exhibits a measurable response to mercury environmental pollution and meets the requirements of a bioindicator

SNF1-related protein kinases type 2 are involved in plant responses to cadmium stress

Cadmium ions are notorious environmental pollutants. In order to adapt to cadmium-induced deleterious effects plants have developed sophisticated defense mechanisms. However, the signaling pathways underlying the plant response to cadmium are still elusive. Our data demonstrate that SNF1-related protein kinases 2 (SnRK2s) are transiently activated during cadmium exposure and are involved in the regulation of plant response to this stress. Analysis of Nicotiana tabacum Osmotic Stress-Activated Protein Kinase (NtOSAK) activity in tobacco BY-2 cells indicates that reactive oxygen species (ROS) and nitric oxide, produced mainly via an L-arginine-dependent process, contribute to the kinase activation in response to cadmium. SnRK2.4 is the closest homologue of NtOSAK in Arabidopsis thaliana. Comparative analysis of seedling growth of snrk2.4 knockout mutants versus wild type Arabidopsis suggests that SnRK2.4 is involved in the inhibition of root growth triggered by cadmium; the mutants were more tolerant to the stress. Measurements of the level of three major species of phytochelatins in roots of plants exposed to Cd2+ showed a similar (PC2, PC4) or lower (PC3) concentration in snrk2.4 mutants in comparison to wild type plants. These results indicate that the enhanced tolerance of the mutants does not result from a difference in the phytochelatins level. Additionally, we have analyzed ROS accumulation in roots subjected to Cd2+ treatment. Our data show significantly lower Cd2+-induced ROS accumulation in the mutants’ roots. Concluding, the obtained results indicate that SnRK2s play a role in the regulation of plant tolerance to cadmium, most probably by controlling ROS accumulation triggered by cadmium ions

Działalność wojskowych bibliotek i ośrodków informacji naukowej w Siłach Zbrojnych Rzeczypospolitej Polskiej

The article presents current activity of libraries of the Polish Armed Forceswhich operate within the departmental framework of the library network (RSB), withparticular emphasis on the Central Military Library. Starting from the structure, number and tasks performed by information institutions in the RSB, and ending with data concerning: structure, number and education of the staff, nature and size of the collections of individual libraries, financial resources for the purchase of library materials and IT-library systems used in these institutions.Artykuł prezentuje bieżącą działalność bibliotek Sił Zbrojnych RP funkcjonujących w ramach resortowej sieci bibliotecznej (RSB), ze szczególnym uwzględnieniem Centralnej Biblioteki Wojskowej. Począwszy od struktury, liczby i zadań, które pełnią placówki informacyjne w RSB, a skończywszy na danych dotyczących: struktury, liczby i wykształcenia kadry pracowniczej, charakteru i wielkości księgozbiorów poszczególnych bibliotek, środków finansowych przeznaczanych na zakup materiałów bibliotecznych oraz systemów informatyczno-bibliotecznych wykorzystywanych w tychże placówkach