Volume 62, Issue 5

Two-component signal transduction system (TCS) is a common mechanism of signal transduction and exists in almost all bacterial species. The putative two-component genes SCO6421 (ecrE1) and SCO6422 (ecrE2) in Streptomyces coelicolor, which located in the vicinity of the red locus, could modulate the antibiotic undecylprodigiosin (Red) biosynthesis. In this study, the mutants of M145E1 (ecrE1 knock-out) and M145E2 (ecrE2 knock-out) were constructed using homologous recombination by double crossover. Red production of two mutants decreased dramatically compared with that of the wild-type strain. However, the production of actinorhodin (Act) of two mutants had not changed significantly. The results suggested that ecrE1/ecrE2 participated in regulating the antibiotic Red synthesis. Northern blotting analysis indicated that ecrE1/ecrE2 may regulate the biosynthesis of Red through influencing the transcription of redD and redZ during cell growth. Therefore, ecrE1/ecrE2, as a specific pair of TCS, most likely regulates the red gene cluster positively.

The influence of different concentration ranges (0–500 mg/L) of ammonium, nitrate and nitrite presence in the wastewater, on the performance of the pure culture of phosphate-accumulating bacterium Acinetobacter junii in the anaerobic and aerobic conditions, was investigated. A. junii was able to use ammonium and nitrate salts as the source of nitrogen, unlike in the case of nitrite salt. Comparing to the control reactors with the peptone and yeast extract as the sources of nitrogen, at the lowest tested concentration of ammonium and nitrate the performance of the system was inhibited due to the nitrogen deficit in the wastewater, while at the highest concentration it was positively influenced. Nitrite in all concentrations detrimentally affected the phosphate release and uptake rates, chemical oxygen demand uptake rates, nitrogen uptake rates, as well as multiplication of A. junii. The higher the nitrite concentration, the more pronounced was the effect. At the highest nitrite concentration tested a complete failure of the system was observed.

Aldehyde dehydrogenase (ALDH) superfamily is a group of enzymes metabolizing endogenous and exogenous aldehydes. Using differential display RT-PCR and cDNA library screening, a full-length aldehyde dehydrogenase cDNA (ALDH7B7) was isolated from rice leaves infected by incompatible race of blast fungus Magnaporthe grisea. The deduced amino acid sequence consists of 509 amino acid residues and shares 74∼81% identity with those of ALDH7Bs from other plants. ALDH7B7 expression was induced by blast fungus infection, ultraviolet, mechanical wound in rice leaves and was not detected in untreated rice organs. This gene has also been found to be inducible after exogenous phytohormones application, such as salicylic acid, methyl ester of jasmonic acid and abscisic acid. The function of ALDH7B7 in the interaction process between blast fungus and rice is discussed.

A modified Agrobacterium-mediated transformation protocol has been successfully used for transient expression of the intrinsically fluorescent proteins and their fusion proteins in onion epidermis. The mean of the transformed cells rate per peel is about 10.5±0.9%, while that of the particle bombardment method is at the range 2.0±0.4%. To compare with the prevailing method of micro-projectile bombardment, the modified Agrobacterium-mediated transformation may provide with higher efficiency and even more simplified manipulability on a lower budget.

Fairy ring is a frequently reported disease of turfgrasses worldwide, and necrotic or severely injured grass are observed in those turf sites exhibiting type-I fairy ring symptoms. The objective of this research was to characterize soil chemical and physical properties at two soil sampling depths (0.5 cm and 3.0 cm) at a turfgrass site exhibiting type-I fairy ring symptoms. Soil samples were obtained from a perennial ryegrass (Lolium perenne L.) golf course fairway at one sampling date in the summer when environmental conditions were most conducive to the appearance of severe type-I fairy ring symptoms. At both soil depths, soil analysis indicated that concentrations of ammonium-nitrogen, potassium, and sulfur were statistically higher in soil underlying necrotic or bare zones versus soil in healthy turfgrass zones. At both soil depths, soil electrical conductivity was statistically higher, and volumetric soil water content was statistically lower in necrotic zones versus soil under healthy turfgrass. At both soil depths, total nitrogen, magnesium, calcium, cation exchange capacity, and organic matter content were not statistically different among necrotic and healthy turfgrass zones. Soil pH was statistically higher in the necrotic zone versus soil under healthy turfgrass at only the 3.0 cm soil sampling depth. Comparing soil properties within the necrotic zone, only potassium and electrical conductivity was statistically higher at the 0.5 cm depth compared to the 3.0 cm depth. Although most soil information was considered very similar at both sampling depths, soil sampling at the 3.0 cm depth would be a more practical or easier method for turfgrass managers. At either soil sampling depth, the necrotic zones of type-I fairy ring areas in turfgrass were most likely associated with a combination of direct and indirect effects of the basidiomycete fungi on soil chemical and physical properties in the turfgrass root zone.

Numerous recent laboratory studies have shown that vegetation can influence soil water flow by inducing very low levels of water repellency. In this study we extended on this previous research by developing a field-based test using a miniature infiltrometer to assess low levels of water repellency from physically based measurements of liquid flow in soil. The field-based test was verified through a simple laboratory experiment and then applied to determine the impact of vegetation and antecedent soil water content. The soil hydraulic properties determined were hydraulic conductivity, sorptivity, as well as the persistence and index of water repellency. Tests were conducted following a dry spell and wet spell on (1) forest soil (0 cm depth), (2) glade soil (0 cm depth) and (3) glade soil (50 cm depth). It was found that both the persistence and index of water repellency, R, decreased in the order as follows: forest soil > glade soil (0 cm) > glade soil (50 cm) for both dry and wet spell. The range of values of R was 0.28 (wettable) to 360 (highly water repellent), which affected hydraulic conductivity k r(−2 cm). R increased and hence k r(−2 cm) decreased in the order: forest soil < glade soil (0 cm) < glade soil (50 cm) for both the dry and wet spell. There were clear interactions between vegetation and changes to water flow caused by presence of repellency.

The way of improving degraded soils fertility and particularly of improving its microbial activity is to add “young” exogenous organic matter that contribute to provide labile organic matter to stimulate the life of the microorganisms existing in the soil. This organic matter will also improve both the retention and hydraulic characteristics of the degraded soils, all this contributing to soil restoration. In this study, the microbiological, biochemical, soil-physical and hydrological effects of the addition of a municipal solid waste compost to a degraded soil in El Campello, SE Spain were evaluated in a field experiment. Soil samples from experimental plots were analyzed 6 and 18 months after soil amendment. In both sampling time treated plots showed significantly higher microbial biomass carbon and dehydrogenase activity values than control, indicating that soil microbial population’s development and activity were stimulated by compost addition, this effect being not ephemeral but lasting in the time. Soil urease activity was not affected by compost addition while protease hydrolysing N-α-benzoil-L-argininamide (BAA) activity was strongly stimulated by the incorporation of compost into the soils. Phosphatase and β-glucosidase activities were also stimulated by the organic amendment, this stimulation being particularly noticeable 18 months after the compost addition. Nevertheless, this increase in soil microbial populations and activity did not result in an increase in soil aggregation and hydrological parameters. This can be due to the high content of carbonates and Ca2+ ions in these calcareous soils, that lead to an initially high content of water-stable macroaggregates.

The influence of plant transpiration on the entropy exchange was quantified as associated with the degradation of solar energy on the Earth’s surface covered by plants. Two surfaces were studied: (1) productive surface — plant transpiration taken as equal to the potential one, (2) non-productive surface — plant transpiration taken as equal to zero. The entropy exchanges associated with the absorption of solar radiation and with the conversion of absorbed solar radiation into the sensible heat and latent heat were taken into account. These processes were examined in the experimental watershed Liz (828–1074 m a.s.l.) located in the Bohemian Forest (Czech Republic). We found that in the growing season 1992 the net entropy exchange in humid hydrologic period (the Earth’s surface is productive) was considerably higher than in the arid one (the Earth’s surface was productive in 39% of days, and non-productive in 61% of days). Considering that the biotic effect on the Earth’s functioning can be measured with the help of the net entropy exchange, we can assume that the theory that biotic activities — represented by plant transpiration here — are the cause of the self-organizing processes in Earth’s environment is proved in the watershed scale.

Water movement and uptake by roots in a drip-irrigated potato field was studied by combining field experiments, outputs of numerical simulations and summary results of an EU project (www.fertorganic.org). Detailed measurements of soil suction and weather conditions in the Bohemo-Moravian highland made it possible to derive improved estimates of some parameters for the dual permeability model S1D_DUAL. A reasonably good agreement between the measured and the estimated soil hydraulic properties was obtained. The measured root zone depths were near to those obtained by inverse simulation with S1D _DUAL and to a boundary curve approximation. The measured and S1D _DUAL-simulated soil water pressure heads were comparable with those achieved by simulations with the Daisy model. During dry spells, the measured pressure heads tended to be higher than the simulated ones. In general, the former oscillated between the simulated values for soil matrix and those for the preferential flow (PF) domain. Irrigation facilitated deep seepage after rain events. We conclude that several parallel soil moisture sensors are needed for adequate irrigation control. The sensors cannot detect the time when the irrigation should be stopped.

Plants can affect soil moisture and the soil hydraulic properties both directly by root water uptake and indirectly by modifying the soil structure. Furthermore, water in plant roots is mostly neglected when studying soil hydraulic properties. In this contribution, we analyze effects of the moisture content inside roots as compared to bulk soil moisture contents and speculate on implications of non-capillary-bound root water for determination of soil moisture and calibration of soil hydraulic properties. In a field crop of maize (Zea mays) of 75 cm row spacing, we sampled the total soil volumes of 0.7 m × 0.4 m and 0.3 m deep plots at the time of tasseling. For each of the 84 soil cubes of 10 cm edge length, root mass and length as well as moisture content and soil bulk density were determined. Roots were separated in 3 size classes for which a mean root porosity of 0.82 was obtained from the relation between root dry mass density and root bulk density using pycnometers. The spatially distributed fractions of root water contents were compared with those of the water in capillary pores of the soil matrix. Water inside roots was mostly below 2–5% of total soil water content; however, locally near the plant rows it was up to 20%. The results suggest that soil moisture in roots should be separately considered. Upon drying, the relation between the soil and root water may change towards water remaining in roots. Relations depend especially on soil water retention properties, growth stages, and root distributions. Gravimetric soil water content measurement could be misleading and TDR probes providing an integrated signal are difficult to interpret. Root effects should be more intensively studied for improved field soil water balance calculations.

Salinization is one of the most important factors affecting agricultural land in the world. Salinization occurs naturally in arid and semiarid regions where evaporation is higher than rainfall. Sugar beet yield declines with an increase in salinity, but the sensitivity to salts varies with salt composition in water and sugar beet growth stage. The aim of this study was to determine the effect of water salinity levels and salt composition on germination and seedling root length of four sugar beet cultivars (PP22, IC2, PP36, and 7233). The experiments were undertaken with irrigation water with two salt compositions (NaCl alone and mixture of MgSO4 + NaCl + Na2SO4 + CaCl2) in three replicates. Thirteen salinity levels with electrical conductivity (EC) of the irrigation water ranging from 0 to 30 dS/m were applied to each cultivar in both experiments. Seed germination percentage and seedling root length growth were determined in 13 days. Statistical analysis revealed that germination and root length were significantly affected by salt composition, cultivars and salinity levels. Regardless of salt composition, seed germination and seedling root length were significantly affected by the irrigation water with EC up to 8 dS/m and 4 dS/m, respectively. Except for cultivar PP22, the adverse effect of salinity of the irrigation water on seed germination and seedling root length was higher for NaCl alone than for the salt mixture, which refers to lower salt stress in field conditions with natural salt composition.

Two organic matter horizons developed under a spruce forest and grass vegetation were chosen to demonstrate the impact of a different vegetation cover on the micromorphology, porous system and hydraulic properties of surface soils. Micromorphological studies showed that the decomposed organic material in the organic matter horizon under the grass vegetation was more compact compared to the decomposed organic material in the organic matter horizon under the spruce forest. The detected soil porous system in the organic matter horizon under the spruce forest consisted of two clusters of pores with different diameters that were highly connected within and between both clusters. The soil porous system in the organic matter horizon under the grass vegetation consisted of one cluster of pores with the larger diameters and isolated pores with the smaller diameter. The retention ability of the organic matter horizon under the grass vegetation was higher than the retention ability of the organic matter horizon under the spruce forest.

The long-term trends of mean monthly nitrate concentrations in stream and drainage runoff were evaluated in the experimental microbasin Rybárik (0.119 km2) at the Institute of Hydrology, Slovak Academy of Sciences, during the period 1987–2005. The results of analyses indicate a decreasing trend of nitrate concentration after the year 1989, but with relatively high losses in some years and relatively low losses in other years. This decreasing trend is mainly caused by a decrease in the use of nitrogen fertilizers. The nitrate concentration in surface runoff strongly correlates with runoff and fertilization. Based on measured data, an empirical relation was found describing the dependence of annual nitrate transport in the stream on annual runoff depth and on the annual amount of applied nitrogen fertilizers.

The larvae of Curteria episcopalis (C.L. Koch, 1837) and Curteria southcotti Gabryś, 1992, are described based on specimens reared in the laboratory. Pedroerythraeus Haitlinger, 2004 is considered a junior synonym of Curteria. Data on habitat specificity and phenology of the species as well as on development of eggs into larvae are given.

A new diplopod species, Anamastigona radmani sp. n., from Croatia, is described, illustrated, and diagnosed. Its relationships with congeners and their geographic distribution are briefly discussed.

The jumping cockroach Skok svaba gen. et sp. n., characteristic of modern reproduction, is described from the Upper Jurassic Karabastau Formation in Kazakhstan, and attributed to a new family Skokidae. The finding demonstrates the immense plasticity of stem cockroaches from which eusocial termites and predatory mantises evolved.

Two species of Spilogona, S. angustigena sp. n. and S. tatrica sp. n., are described from the Czech Republic and Slovakia, respectively. Both species are characterised by a gynaecomorphic shape of the male head, i.e., by a broad frons and the presence of a pair of orbital setae. Three species with this type of head are already known in the Palaearctic region: S. karelica (Tiensuu, 1935) from Russian Karelia, S. lapponica (Ringdahl, 1932) occurring in Norway and Sweden and redescribed here from material collected recently in Russia and Sweden, and S. spinicosta (Stein, 1907) from Tibet. All five species are compared and a new identification key is given. Apart from the external similarity of the male heads, the species under study are hardly closely related and their dichoptic heads may be explained as a homoplasy among similar ecomorpha.

Benthic macroinvertebrates associated with four species of macrophytes (Nymphoides peltata, Ceratophyllum demersum, Polygonum amphibium and Carex sp.) were investigated during two growing seasons (2001 and 2002) in the slow-flowing Čonakut Channel in the Kopački rit Nature Park in Croatia. A total of 31 macroinvertebrate taxa were found. C. demersum, a submerged plant with dissected leaves, supported the highest macroinvertebrate abundance, almost seven times more than N. peltata, a floating plant with undissected leaves, which harboured the lowest abundance during the research period. Chironomidae larvae (50–83%) and Oligochaeta (14–46%) were the most abundant groups recorded on all macrophyte species. Water-level fluctuation, because of its influence on the appearance and growth of aquatic vegetation, and the trophic state of water within the macrophyte stands seemed to be the main factors which affected the taxonomic composition and abundance of macroinvertebrates.

The gut contents of adult Xanthoperla apicalis and Siphonoperla torrentium were analysed. X. apicalis females eat mainly pollen, while males feed principally on detritus and pollen. Adults of S. torrentium, regardless of sex, eat mainly pollen. The presence of animal remains (claws and leg and antennae segments of Arthropoda) in the gut of several individuals of both species was observed and discussed.

In two successive years we recorded a total of 3,636 individuals and 17 species of adult lady beetles (Coleoptera, Coccinellidae) in the spruce forests of Pol’ana Mts (the West Carpathians) at altitudes ranging from 600 m to 1,300 m a.s.l. Four lady beetle species were documented as predominating (dominance of abundance > 5%) over the study period. They were the following: Aphidecta obliterata (1,828 individuals and 50.3%), Coccinella septempunctata (634 individuals and 17.4%), Adalia conglomerata (594 individuals and 16.3%) and Anatis ocellata (279 individuals and 7.7%). The assemblages of lady beetles differed among the areas and also between the years. The season revealed neglegible effect on distribution of lady beetles, whereas the effect of altitude was more pronounced. A. conglomerata preferred the areas at lower altitude (600–725 m) to those at middle (900–925 m) and/or upper altitude (1,250–1,300 m). In contrast, A. obliterata and C. septempuctata were most abundant in the area at middle altitude. The altitudinal location of area partly explained the variability in abundance of lady beetles. The first ordination axis constructed by means of correspondence analysis (CA) represented an altitudinal gradient and accounted for 19.4% of the total variance of the species data. The great proportion of lady beetle species not typically associated with spruce and/or other coniferous trees than spruce (70.6%, n = 17) may be explained by an ecotonal effect.

Bird population density and their behaviour during non-breeding periods are determined mainly by meteorological conditions which force birds to use alternative strategies — migration to areas with more advantageous conditions or adaptation to existing conditions. During the 2002/03–2004/5 non-breeding seasons in the open habitats of the Kotlina Orawsko-Nowotarska valley (S Poland) studies on population dynamics, behaviour and habitat use of great grey shrike were conducted. Results were grouped into four meteorological periods (autumn, early winter, winter and early spring). Density changes were seen between subsequent seasons (from 0.34 to 1.9 ind./10 km), as well as between meteorological periods (from 0.48 to 2.70 ind./10 km). Perching was the most frequently observed behaviour. The foraging habitats used changed in frequency. In subsequent meteorological periods a decrease of open habitats used was noted with a simultaneous increase in afforestations used. These changes did not depend on lasting snow cover. Changes in vegetation type used during hunting were not observed. Great grey shrikes most frequently used natural perches (trees, shrubs and high vegetation).

The aim of this research is to determine the probability of anterior and posterior presentation during the second half of gestation and at delivery among albino mice. Each day from the 10th to the 21st day of gestation, foetal presentation and lie were determined in uteri of six pregnant females. The chi-square test did not show any statistically significant difference in the incidence of anterior and posterior presentation between the right and left horn. In addition, there was no significant difference between anterior and posterior presentation in relation to the site in the horn or in relation to gestation days. At delivery, there was no significant difference in the incidence of anterior and posterior presentation (29 versus 31 cases). The results show that, in the albino mouse, foetal presentation during the second half of gestation and at birth is accidental, with equal probability for anterior and posterior presentation.

Derivatives of 2-aryl-substitute (o-hydroxy-, m-bromo-, o-methoxy-, o-nitro-phenyl or 4-pyridyl) benzothiazole were synthesized and tested for their mutagenicity in in vitro assays: (i) in the Ames test with Salmonella typhimurium TA98 and TA100 strains; and (ii) in the sister chromatid exchange (SCE) in cultured human lymphocytes. The four of compounds (BT-11, B-12, BT-14 and BT-15) caused statistically significant increase in revertant colonies of TA98 and TA100. Treatment of lymphocytes with compounds also caused a significant increase in SCE/cell in association with high levels and long exposure (300 µg/mL and 48 h) of the four compounds. It can be concluded that benzothiazole derivatives showed mutagenic activity and were also able to exert a genotoxic effect reducing both the replication index and mitotic index.

Glial fibrillary acidic protein (GFAP) is an intermediate filament protein considered to be the best astroglial marker. However, the predominant cell population in adult human brain tissue cultures does not express GFAP; these cells have been termed “glia-like” cells. The basic question about histological origin of adult human brain cultures remains unanswered. Some authors showed that “glia-like” cells in adult human brain cultures might be of non-glial origin. We examined primary explant tissue cultures derived from 70 adult human brain biopsies. Within first 5–10 days approximately 5–10% of the small explants became attached. Outgrowing cells were mostly flat cells. These cells formed confluent layer over 3–6 weeks in culture. At confluence the cultures contained 2–5% of microglial cells, 0.1% GFAP-positive astrocytes, less than 0.01% oligodendrocytes and 95–98% GFAP-negative “glia-like” cells. This population of flat “glia-like” cells was positively stained for vimentin, fibronectin, and 20–30% of these cells stained for nestin. Our findings revealed that 1 mM dibutyryl-cAMP addition, in serum free conditions, induced a reversible stellation in 5-10% of the flat “glia-like” cells but did not induce the expression of GFAP or nestin in morphologically changed stellate cells. These results demonstrate that “glia-like” cells in primary adult human brain cultures constitute heterogeneous cell populations albeit with similar morphological features. Two distinct subpopulations have been shown: (i) the one immunostained for nestin; and (ii) the other reactive for dibutyryl-cAMP treatment.