Effect of ectomycorrhizal infection on growth and photosynthetic characteristics of <Emphasis Type="Italic">Pinus densiflora</Emphasis> seedlings grown under elevated CO<Subscript>2</Subscript> concentrations

The effect of ectomycorrhizal Pisolithus tinctorius (Pt) infection was studied on the growth and photosynthetic characteristics of Pinus densiflora seedlings grown at ambient (360 µmol mol⁻¹, AC) and elevated (720 µmol mol⁻¹, EC) CO₂ concentrations. After 18 weeks, Pt inoculation had led to significantly increased dry mass and stem diameter of P. densiflora at both CO₂ concentrations, relative to non-inoculated seedlings. Moreover, EC significantly increased the ectomycorrhizal development. The phosphate content in needles inoculated with Pt was about three times higher than without inoculation at both CO₂ concentrations. The PAR saturated net photosynthetic rates (P _sat) of P. densiflora inoculated with Pt were clearly higher than for control seedlings at both CO₂ concentrations, and the maximum net photosynthetic rate (P _N) at saturated CO₂ concentration (P _max) was higher than in controls. Moreover, the carboxylation efficiency (CE) and RuBP regeneration rate of the P _N/C _i curve for P. densiflora inoculated with Pt were significantly higher than for non-inoculated seedlings at both CO₂ concentrations, especially at EC. The water use efficiency (WUE) of seedlings inoculated with Pt grown at EC was significantly raised. Allocation of photosynthates to roots was greater in Pt inoculated pine seedlings, because of the enhanced activity of ectomycorrhiza associated with seedlings at EC. Moreover, P _N of non-inoculated seedlings grown for 18 weeks at EC tended to be down regulated; in contrast, Pt inoculated seedlings showed no down-regulation at EC. The activity of ectomycorrhiza may therefore be enhanced physiological function related to water and phosphate absorption in P. densiflora seedlings at EC.This study was partly sponsored by the Ministry of Education, Sport, Culture, Science and Technology of Japan (RR2002, Basic Research B and Sprout study).     

两种国兰C类花发育MADS基因的克隆与表达研究

该研究以蕙兰(Cymbidium faberi)和墨兰(Cymbidium sinense)为材料,利用RT-PCR对AGAMOUS (AG)基因进行克隆,并利用qRT-PCR进行组织表达.结果 表明:(1)获得3个AG基因均属于植物特有的C类MIKC型MADS-box基因,其中2个蕙兰AG基因命名为CfAG1(登录号...     

Reproductive characteristics and reproductive tract anatomy of the California butterfly ray Gymnura marmorata (Myliobatiformes: Gymnuridae)

The California butterfly ray Gymnura marmorata is frequently caught by artisanal fisheries in north-western Mexico (Baja California Sur; BCS). The aim of this study was to estimate reproductive characteristics and describe the micro and macroscopic reproductive structures of female and male G. marmorata. Sampling was carried out at two fisheries landing sites located on the west coast BCS, from 2008 to 2012. The largest disc width (W_D) ever recorded for this species was 131.0 cm and females were larger than males. The male sample was composed exclusively of adult specimens, with a median size at 50% maturity (W_D50) estimated at 44.9 cm W_D. For females, size at onset of maturity was estimated at 63.0 cm W_D; W_D50, at 64.7 cm W_D; and size at pregnancy at 80.1 cm W_D. Gonadal asymmetry was observed for the first time in this species. Indeed, in males only the left testis was functional (testicular asymmetry), while in females, only the left ovary was functional (ovarian asymmetry).     

Metabolic responses during initial days of altitude acclimatization in the Eastern Himalayas

The study was carried out on 16 men (aged 20–30 years) to evaluate daily metabolic responses during the early phase of altitude acclimatization at moderate altitudes between 3100 and 4200 m in the Eastern Himalayas. Resting (R) and submaximal exercise (E) oxygen consumption (|VO₂) at 100 W at sea level (SL) were 3.25 (SEM 0.15) and 20.31 (SEM 0.77) ml/kg per min respectively. On day 1 at 3110 m both R and E |VO₂ decreased (P<0.001) and subsequently remained constant. At 3445 m these values tended to increase over the 3110 m values but were lower than the SL values. At 4177 m the decline in |VO₂ was significantly greater (P<0.01) than at the preceding altitudes. Pulmonary ventilation (|VE) increased consistently (P<0.001) with increase in altitude. The arterial oxygen saturation (S _a O₂) at different altitudes was lower (P<0.001) than SL values. The cardiac frequency (f _C ) at R and E was higher (P<0.001) at altitude; the values at 3110 and 3445 m were significantly lower (P<0.001) than at 4177 m. Blood pressure (BP) increased (P<0.001) on the first day at each altitude. The systolic BP tended to decline towards SL values but the diastolic BP remained high (P<0.001) throughout. The resting blood lactic acid concentration, [la ^–] _bl , showed a decline (P<0.001) only at 4177 m. The [la ^–] _bl at E was similar at 3110 and 3445 m but was higher (P<0.01) at 4177 m. These observations suggest that acclimatization to a mid-altitude of 3445 m can be safely avoided where rapid ascent to higher altitude is required.     

Effects of relative humidity on development, fecundity and survival of three storage mites

The developmental rate of immature stages and the reproduction of adults of Tyrophagus putrescentiae (Schrank), T. neiswanderi Johnston and Bruce and Acarus farris (Oudemans) were examined at 70, 80 and 90% r.h. and a constant temperature of 25°C. At 70% r.h., T. putrescentiae and A. farris immature stages failed to reach the protonymph stage as 100% of the larvae died, whereas T. neiswanderi was able to complete development. The developmental time of all immature stages for the three species was significantly increased as relative humidity was reduced. The mobile stages were particularly susceptible, as the time needed to complete their development at lower relative humidities suffered greater increases than the egg stage. At 70% r.h., T. putrescentiae and A. farris were not able to lay eggs and only 24% of T. neiswanderi pairs were fertile. The reproductive parameters of the three species at the relative humidities at which they were able to lay eggs showed significant differences, except for the percentage of fertile mating at 80 and 90% r.h. As relative humidity increased, preoviposition period was reduced and fecundity and daily fecundity was increased, whereas the oviposition period showed different patterns for the three species. The intrinsic rate of increase (r _m ) of T. neiswanderi at 70% r.h. was negative indicating that, at these conditions, mite populations of this species will diminish until they disappear. As relative humidity increased from 80 to 90% r.h. this parameter was almost twofold for both Tyrophagus species. The r _m obtained for A. farris at 90% r.h. was similar to that of T. neiswanderi at the same humidity while at 80% r.h. it was very small so that the population doubling time was more than 84 days. The influence of relative humidity on biology of these mites and its practical application as control measure are discussed.     

Thermal stability and biochemical properties of isocitrate dehydrogenase from the thermoacidophilic archaeon <Emphasis Type="Italic">Thermoplasma acidophilum</Emphasis>

Isocitrate dehydrogenase [IDH; EC 1.1.1.42] from the thermoacidophilic archaeon Thermoplasma acidophilum (TaIDH) showed high thermal stability with an apparent melting temperature, T _m, of 82.2 and 84.5°C at pH 7.5 and 5.8, respectively. Based on structural alignment of TaIDH with IDH from Aeropyrum pernix (ApIDH) and Archaeoglobus fulgidus (AfIDH) residues forming an aromatic cluster in the clasp-domain thought to strengthen the dimer interface in ApIDH and AfIDH were identified in the former enzyme. Moreover, TaIDH had a shortened N-terminus that may protect the enzyme from thermal denaturation. The enzyme activity of TaIDH was highest at 70°C. The pH-activity profile was bell-shaped with an optimum shifted to a lower pH compared to AfIDH. The activity of TaIDH was influenced by changes in pH with a three-fold reduction in activity when the pH was shifted from the pH-optimum at 7.5 to pH 5.8. However, the specific activity at pH 5.8 was still high when compared with AfIDH. The reduction in activity at pH 5.8 was not due to instability of the enzyme as the T _m of TaIDH was higher at pH 5.8 than at 7.5 and the enzyme retained 91% of its activity after incubation at 1 h at pH 5 and 60°C. The difference in the pH-profile of TaIDH in comparison with AfIDH may thus be related to the pK _as of their catalytic residues involved in the initial proton abstraction and the final proton donation during the catalysis of oxidative decarboxylation of isocitrate to 2-oxoglutarate and reduced coenzyme.     

Mapping of cysteine genes on the chromosome of Pseudomonas aeruginosa PAO

Summary Three loci coding for different steps in the pathway of cysteine biosynthesis have been mapped by R68.45-mediated coconjugation analysis. The cysteine auxotrophic mutants could be subdivided into sulfite and sulfide-requiring mutants. Sulfide-requiring mutants (cysIV group) were localized at a single position between pyrF and pur-67, while sulfite-requiring mutants (cysI and cysII) mapped at two different regions. The cysI group was also localized between pyrF and pur-67, although more distal to pyrF than the cysIV group. This group included the cys-54 marker, which has been mapped previously. The second group of sulfite-requiring mutants, designated as cysII, was cotransducible with hisI and localized at the end of the PAO chromosomal map. This location was also confirmed for the marker cys-59.The marker cys-59 (which was cotransducible with his1) was cotransferred by R68.45-mediated conjugations with both the late marker pur-67 and the early marker ilv-226. As the late marker hisI was positioned at about 60–65 min (Herrmann and Günther, in press) the length of the PAO chromosome was estimated to be about 70 min.     

Expression of Apoptotic and Antioxidant Enzyme Genes in Sheep Oocytes and In Vitro Produced Embryos

The present study was to find out the expression pattern and relative expression level of apoptotic (Bcl2, Bax, Casp3, and PCNA) and antioxidant enzyme [(GPx, Cu/Zn-SOD (SOD1) and Mn-SOD (SOD2)] genes in sheep oocytes and developing embryos produced in vitro by conventional RT-PCR and real time qPCR, respectively. Different developmental stages of embryos were produced in vitro from oocytes collected from local slaughter house ovaries. RT-PCR amplicons showed expression of Bcl2 and PCNA in all stages except at morula. In contrast Bax and Casp3 were expressed in all stages. GPx and SOD1 were expressed in all stages but SOD2 was not expressed in 8–16 cells, although expressed in the remaining stages. The qPCR analysis reflected that Bcl2 expression was significantly (P < 0.05) downregulated in morula and maximum upregulated expression was observed in in vitro matured oocytes. Higher upregulated expression (P < 0.05) of Bax was in morula and downregulated expression was at 2-4 cells. Casp3 was significantly upregulated at 8–16 cells and downregulated in in vitro matured oocyte. PCNA expression was highest at blastocyst and least expression was at morula. GPx was expressed significantly highest in matured oocytes and least expression was at zygote. SOD1 was expressed significantly highest at 8–16 cells and least expression was at zygote. Expression of SOD2 was least among all the antioxidant enzymes but significantly higher expression of SOD2 was in immature oocyte; however, least expression was at 8–16 cells. It can be concluded from the study that the sheep embryos produced in vitro are highly sensitive to culture condition, which alters the expression level of apoptotic and antioxidant enzyme genes.     

Characterization of a broad range antibacterial substance from a new <Emphasis Type="Italic">Bacillus</Emphasis> species isolated from Amazon basin

A Bacillus sp. strain producing a bacteriocin-like substance was characterized by biochemical profiling and 16S rDNA sequencing. The phylogenetic analysis indicated that this strain has low sequence similarity with most Bacillus spp., suggesting a new species was isolated. The antimicrobial activity was detected starting at the exponential growth phase, and maximum activity was observed at stationary phase. The substance was inhibitory to a broad range of indicator strains, incluing pathogenic and food spoilage bacteria such as Listeria monocytogenes, B. cereus, Aeromonas hydrophila, Erwinia carotovora, Pasteurella haemolytica, Salmonella Gallinarum, among other. The antibacterial substance was stable over a wide pH range, but it was sensitive to pronase E and lipase. The antibacterial substance was bactericidal and bacteriolytic to L. monocytogenes and B. cereus at 160 AU ml⁻¹. The identification of a broad range bacteriocin-like inhibitory substance active against L. monocytogenes addresses an important aspect of food protection against pathogens and spoilage microorganisms.     

Laboratory studies on the life-histories of four enchytraeid worms (Oligochaeta) which inhabit sewage percolating filters

The life-histories of four enchytraeid worms, Lumbricillus rivalis, Enchy-traeus coronatus, E. buchholzi, and E. albidus which occur in sewage percolating filters, were studied under laboratory conditions at 8 , 15 and 20°C. The number of ova per cocoon varied from 0 to 50 (L. rivalis), 0 to 33 (E. coronatus), 1 to 9 (E. buchholzi) and 0 to 22 (E. albidus). The mean number of ova per cocoon was highest at 15°C for all species except E. coronatus which had a highest mean value at 8°C. The number of ova in cocoons was correlated with cocoon length (P < 0.001) for all species. Cocoon production usually increased with temperature ranging from 0.8 cocoons per adult per week at 8°C to 2.0 at 20°C for L. rivalis, and from 1–4 to about 2.6 for E. coronatus and E. buchholzi. The total number of ova produced by each E. coronatus (350 at 8°C to 550 at 20°C) was similar to that produced by each L. rivalis (600 at 8°C to 350 at 20°C) and was about five times greater than the total numbers produced by the other two species. Cocoon and ova production and the number of ova per cocoon varied with the age of the adult, usually reaching a peak soon after maturity. Hatching success was low and generally 40–50 % of ova failed to develop; subsequent mortality among immature worms was about 10–20%. Growth was more rapid at the higher temperatures; L. rivalis matured in about 26 days at 20°C, the clitellum forming when the worm was 13–14 mm long; data for the other species are 13 days and 5–6 mm (E. coronatus); 16 days and 3–4 mm (E. buchholzi); 28 days and 13–14 mm (E. albidus). The maturation period at 8°C was at least twice that at 20°C. The generation period (cocoon to cocoon) was about a month at 20°C for all species except E. albidus (2 months), but as some species had longer reproductive periods than others the actual number of generations per year was highest in E. buchholzi, 7.0 per year, and lowest in E. albidus, about 3.3 per year, At 8°C all four species had between 1.4 and 2.8 generations a year. A comparison of expected and observed population densities of L. rivalis and E. coronatus in a sewage percolating filter showed that neither achieved values approaching their potential summer densities although ample food was apparently available. Of the four species studied only E. buchholzi produced viable ova without pairing.     

Frequency of occurrence of mangrove fungi from the east coast of India

This paper describes the frequency of occurrence and biodiversity of fungi from mangroves of the Godavari and Krishna deltas, on the east coast of India. Seventy three species were identified from Godavari and 67 from the Krishna mangroves. Fifty five species were common to both sites, 18 were found only at Godavari and 12 at Krishna mangroves. Verruculina enaliawas found to be very frequent at both sites with a higher frequency of occurrence at Godavari. Eutypa bathurstensis was very frequent at Godavari but only frequent at Krishna. Cirrenalia pygmea and Cryptosphaeria mangrovei were frequent at the Godavari mangrove, but were recorded occasionally at Krishna. Decaying samples of Rhizophora and Avicennia were studied in detail. Forty three species were common to both hosts, while 22 species were recorded only from Avicennia and 20 only from Rhizophora. Verruculina enalia was the only very frequent fungus recorded on both hosts with a lower percentage occurrence (14.8%) on R. apiculata as compared to Avicennia spp. (24.3%). Eutypa bathurstensis was the next most frequent fungus on Avicennia, while Rhizophila marina was next most frequent on Rhizophora. Dactylospora haliotrepha which was recorded frequently on Rhizophorawas infrequent on Avicennia.     

Comparison of extracellular Escherichia coli AppA phytases expressed in Streptomyces lividans and Pichia pastoris

A phytase gene (appA) from Escherichia coli was cloned into Streptomyces lividans and expressed as an extracellular protein which was then compared with the same enzyme expressed in Pichia pastoris. The phytase expressed in S. lividans was not glycosylated and had a molecular mass of 45 kDa. Compared with the glycosylated phytase expressed in P. pastoris, this non-glycosylated phytase was 25–50% less active (p<0.05) at pH 2 to 3.5 or at 45 and 55 °C, but 50% more active (p<0.05) at 75 °C. The thermo-tolerance of the non-glycosylated phytase was 26 and 48% higher (p<0.05) than that of the glycosylated phytase at 45 and 55 °C, but was 80 and 94% lower (p<0.05) at 65 ° and 75 °C, respectively.     

The air spora close to a compost facility in Northeast Oklahoma: Part I—spore trap sampling

A compost facility in northeast Oklahoma is located relatively close to a residential area and is the focus of complaints about smell and concerns about health effects. Several species of Aspergillus have been known to cause health problems, and at least one of these species is dominant in compost. The atmosphere surrounding the compost facility was monitored for 1 year using Burkard spore traps to determine if there was a significant difference in Penicillium/Aspergillus type spores concentration between a test and control site. Samplers were situated 710 m downwind for the test site and 6,085 m upwind at the control site. There was no significant difference in mean concentration of Penicillium/Aspergillus type spores between the two sites (t = 0.576 P > 0.05). The mean concentration of total spores was significantly higher at the upwind control site (t = −7.64, P < 0.01). Wind direction was examined to determine if the compost facility was a possible source for any spikes in concentration. No clear relationship was found between wind direction and mean Penicillium/Aspergillus concentration at the test site, but peak concentrations of Penicillium/Aspergillus seen at the test site were on days when it was downwind from the composting facility. However, these concentrations were no higher than those seen at the control site on other days. If the compost was releasing large amounts of Penicillium/Aspergillus type spores into the atmosphere they were generally diluted to background levels by the time they reached the test site.     

Syntheses of Unsaturated Lactones

6-Pentyl-α-pyrone, 6-propyl-α-pyrone and 4-decenoic acid-δ-lactone were prepared, and the nature of their flavors was investigated. Unsaturated lactones having the best flavorous nature as a butter or butter cake flavor among the lactones having double bond at various site, were 2-ene-δ-lactones which have a double bond at the α-position of the lactone ring and α-pyrones which have two double bonds at the α- and γ-positions. The flavor of 4-deceno-δ-lactone which has a double bond at the γ-position was the worst of them.     

HU Participates in Expression of a Specific Set of Genes Required for Growth and Survival at Acidic pH in <Emphasis Type="Italic">Escherichia coli</Emphasis>

The major histone-like Escherichia coli protein, HU, is composed of alpha and beta subunits respectively encoded by hupA and hupB in Escherichia coli. A mutant deficient in both hupA and hupB grew at a slightly slower rate than the wild type at pH 7.5. Growth of the mutant diminished with a decrease in pH, and no growth was observed at pH 4.6. Mutants of either hupA or hupB grew at all pH levels tested. The arginine-dependent survival at pH 2.5 was diminished approximately 60-fold by the deletion of both hupA and hupB, whereas the survival was slightly affected by the deletion of either hupA or hupB. The mRNA levels of adiA and adiC, which respectively encode arginine decarboxylase and arginine/agmatine antiporter, were low in the mutant deficient in both hupA and hupB. The deletion of both hupA and hupB had little effect on survival at pH 2.5 in the presence of glutamate or lysine, and expression of the genes for glutamate and lysine decarboxylases was not impaired by the deletion of the HU genes. These results suggest that HU regulates expression of the specific set of genes required for growth and survival in acidic environments.     

Sensitive assay of trimethylamine N-oxide in liver microsomes by headspace gas chromatography with flame thermionic detection

To compare the trimethylamine N-oxygenase activity of liver microsomes from house musk shrew (Suncus murinus) and rat, a sensitive method for the quantitation of trimethylamine (TMA) N-oxide was developed using gas chromatography with flame thermionic detection. The limit of quantification was 0.5 μM and the calibration curve was linear at least up to 5 μM in incubations containing liver microsomal preparations from Suncus. The intra-day RSD values ranged from 10.4 to 12.8 at 0.5 μM and from 3.5 to 6.7 at 5 μM. The inter-day RSD values were 11.6 and 6.5 at 0.5 and 5 μM, respectively. This method provides a sensitive assay for TMA N-oxygenase activity in liver microsomes. Using this method we found that Suncus was capable of N-oxidizing trimethylamine at a very slow rate.     

The mixture of tertiary and quaternary alkaloids isolated from Argemone ochroleuca inhibits spore germination of some fungi

The mixture of tertiary and quaternary alkaloids isolated from Argemone ochroleuca was separately assessed against spore germination of some plant pathogenic fungi, e.g. Alternaria alternata, Alternaria brassicae, Alternaria cajani, Bipolaris sp., Curvularia lunata, Curvularia sp., Colletotrichum musae, Fusarium udum, Helminthosporium sp., Helminthosporium pennisetti and Helminthosporium speciferum. Spore germination of Fusarium udum and Helminthosporium sp. was completely inhibited at very low concentration (200 ppm). A similar effect was observed on A. alternata, C. musae and H. pennisetti at 600, 800 and 1000 ppm. With quaternary alkaloids, Curvularia sp. and Colletotrichum musae were most sensitive as complete inhibition of spore germination was observed at 400, 600, 800 and 1000 ppm and a similar effect was observed with A. brassicae and A. cajani at 600, 800 and 1000 ppm. The remaining fungi were also highly sensitive to the mixture at different concentrations.     

Primate diversity,habitat preferences,and population density estimates in Noel Kempff Mercado National Park,Santa Cruz Department,Bolivia

This report documents primate communities at two sites within Noel Kempff Mercado National Park in northeastern Santa Cruz Department, Bolivia. Diurnal line transects and incidental observations were employed to survey two field sites, Lago Caiman and Las Gamas, providing information on primate diversity, habitat preferences, relative abundance, and population density. Primate diversity at both sites was not particularly high, with six observed species: Callithrix argentata melanura, Aotus azarae, Cebus apella, Alouatta caraya, A. Seniculus, and Ateles paniscus chamek. Cebus showed no significant habitat preferences at Lago Caiman and was also more generalist in use of forest strata, whereas Ateles clearly preferred the upper levels of structurally tall forest. Callithrix argentata melanura was rarely encountered during surveys at Lago Caiman, where it preferred low vine forest. Both species of Alouatta showed restricted habitat use and were sympatric in Igapo forest in the Lago Caiman area. The most abundant primate at both field sites was Ateles, with density estimates reaching 32.1 individuals/km² in the lowland forest at Lago Caiman, compared to 14.1 individuals/km² for Cebus. Both Ateles and Cebus were absent from smaller patches of gallery forest at Las Gamas. These densities are compared with estimates from other Neotropical sites. The diversity of habitats and their different floristic composition may account for the numerical dominance of Ateles within the primate communities at both sites. Am. J. Primatol. 46:197–211, 1998. © 1998 Wiley-Liss, Inc.