Meiotic analysis ofElymus caucasicus,E. longearistatus,and their interspecific hybrids with twenty-threeElymus species (Triticeae,Poaceae)

Interspecific hybridizations were carried out between the two tetraploidsElymus caucasicus andE. longearistatus, and 23 tetraploids and hexaploids ofElymus containing SH, SY, SYH, and SYW genomes and representing various geographical regions. Meiotic pairing was studied in the two target species and their hybrids. It is concluded from this study that (i) interspecific hybridization is fairly easy to perform although strong reproductive barriers exist between the species; (ii)Elymus caucasicus andE. longearistatus are allotetraploids, and share the diverged SY genomes; (iii) the divergence of SY genomes is correlated with the geographic distance between theElymus spp. studied.     

New Triterpene Glycosides from an Ulosa sp. Sponge

New triterpene glycosides, ulososides C, (20S,22S,23R,24S)-3,22,23-trihydroxy-3-O-(-D-glucopyranosyl)-32-nor-24-methyllanost-8(9)-ene-30-oic acid, D, (20S,22S,23R,24S)-3,22,23-trihydroxy-3-O-(-D-N-acetylglucosaminopyranosyl)-32-nor-24-methyllanost-8(9)-ene-30-oic acid, and E, (20S,22S,23R,24S)-3,22,23-trihydroxy-3-O-(-D-glucuronopyranosyl-(1 2)--D-arabinopyranosyl-32-nor-24-methyllanost-8(9)-ene-30-oic acid, were isolated from an Ulosa sp. sponge. Their structures were determined by spectral methods and chemical transformations. Specific features of their structures are discussed.     

Homologies in processing and sequence between the 23S ribosomal ribonucleic acids of Paracoccus denitrificans and Rhodopseudomonas sphaeroides

We have shown that mature 50S ribosomal subunits of Paracoccus denitrificans lack intact 23S rRNA, containing instead rRNAs of 0.56 (16S) and 0.37 (14S)x10⁶ molecular weight. Kinetic labelling studies showed these to be derived from a 1.02x10⁶ dalton precursor, which may itself derive from a larger and very transient 23S species. A similar pattern of rRNA processing has been previously described for Rhodopseudomonas sphaeroides, and we have compared, by Tl oligonucleotide catalog analysis, the smaller (14S) fragments of P. denitrificans and R. sphaeroides 23S rRNAs. These were shown to exhibit strong sequence homology, and comparisons of 14S-derived oligonucleotides to oligonucleotides from an in vitro-generated 13S fragment of Escherichia coli 23S rRNA suggest that P. denitrificans and R. sphaeroides 14S rRNAs arise from the 5-terminal portions of their respective 23S precursors. Results are considered to be consistent with the claim that P. denitrificans arose, by loss of photophosphorylation, from a member of the Rhodospirillaceae.Abbreviations E buffer 60 ml 2 M Tris base, 20 ml 3 M sodium acetate, 15 ml 0.2M disodium EDTA, 6 ml glacial acetic acid, 900 ml distilled water - HEPES N-2-hydroxymethyl piperazine-N-2-ethanesulfonic acid - TMK 5 mM Tris-Cl, 0.1 mM MgSO₄, 60 mM KCl. pH 7.3 - TM3 10 mM Tris-Cl, 1 mM MgCl₂, pH 7.3 - Tris tris (hydroxymethyl) aminomethane - SDS sodium dodecyl sulphate     

Quantitative estimation of the surface carbohydrates on the infection structures of rust fungi with enzymes and lectins

Lectins of Triticum vulgaris (WGA), Concanavalia ensiformis (ConA), Phaseolus vulgaris (PHA), Lotus tetragonolobus (LTA), Arachis hypogaea (PNA), Ricinus communis (RCA I), Griffonia simplicifolia (GSA II) and the enzymes endo-(13)--D-glucanase, exo-(13)--D-glucanase and laminarinase were tested for binding to the infection structures of Puccinia coronata and Uromyces appendiculatus. The enzymes and lectins were labeled with fluorescein and the fluorescence was measured with a microscope photometer. GSA II and ConA bound to all parts of the two rust fungi to a certain extent. The germ tubes of P. coronata bound at least two times more WGA than did the germ tubes of U. appendiculatus. The appressoria of both rust fungi additionally bound exo-(13)--glucanase, endo-(13)--glucanase and laminarinase. The substomatal vesicle and the infection hypha of both rust fungi mainly bound the glucanases. Furthermore, the substomatal vesicle of U. appendiculatus bound PHA. No obvious binding with LTA, RCA I and PNA was observed. Binding generally could be inhibited by appropriate haptens. Binding to uredospores generally appeared unspecific. The results indicate that the germ tubes have chitin on their outer surfaces, the appressoria chitin and glucans and the substomatal vesicles and infection hyphae mainly glucans. Compared to P. coronata, U. appendiculatus has more terminal linked glucose residues or the glucan has more (13)--linkages. Also, U. appendiculatus has N-acetylgalactosamine or a similar sugar on the surface of the substomatal vesicle.Abbreviations ConA Concanavalia ensiformis agglutinin - FITC fluorescein isothiocyanate - GSA II Griffonia simplicifolic agglutimin II - LTA Lotus tetragonolobus agglutinin - PBS phosphate buffered saline - PNA Peanut agglutinin - RCA I Ricinus communis agglutinin I - PHA Phaseolus vulgaris agglutinin - WGA Wheat germ agglutinin     

Sisal plant regeneration via organogenesis

Callus was initiated from in vitro grown immature leaf and ex vitro grown mature leaf and rhizome explants of Agave sisalana Perr. ex. Engelm, on MS medium containing 2,4-D (9.05 M) and kinetin (4.6 M) or 2,4-D (9.05 M), kinetin (4.6 M) and CH (1000 mg l^–1) or mod. MS (NH₄NO₃, 1500 mg l^–1) containing 2,4-D (9.05 M) and kinetin (4.6 M). Light was essential for callus formation which, however, was different in three types of explants on three different media compositions. Increasing NH₄ ⁺had a negative impact while addition of CH had a positive impact on callus formation. Shoot regeneration from callus from CH-supplemented medium only was achieved for rhizome and immature leaf tissues. The highest rate of regeneration was obtained with BA (26.6 M) as the sole hormone. Shoot buds g^–1 callus varied according to BA concentrations. Shoot proliferation rate increased on half-strength MS medium containing BA (8.9 M). Microshoots developed on MS medium containing BA (2.22 M) and GA₃ (1.44 M) and finally rooted on MS medium containing IAA (11.42 M). Acclimatized rooted plantlets are growing satisfactorily in ex vitro. This is the first report on plant regeneration via organogenesis of A. sisalana.     

Lipooligosacc haridic antigens fromMycobacterium kansasii andMycobacterium gastri

A set of Lipooligosaccharides (LOSs) has previously been characterized inM. gastri W471. The structure of the highly antigenic LOS (LOS-III) was elucidated and this molecule can unambiguously distinguishM. gastri from the opportunistic pathogenM. kansasii. In the present study, the structures of three otherM. gastri W471 LOSs were determined by one-dimensional¹H-NMR spectroscopy and gas liquid chromatography. They differ by the number of Xylp units and by the structure of the distal monosaccharide. The two dimensional (2D) NMR approach was successfully applied to the LOS antigen ofM. kansasii to locate the acetyl and acyl substituents and to determine the anomeric configuration of the -d-Fucp unit.The molecular specificity of anti-LOS-III antibodies was investigated and the LOS-III epitope was defined as the distal disaccharide: 3,6-dideoxy-4-C-(1,3-dimethoxy-4,5,6,7-tetrahydroxy-heptyl)--xylohexp-(1 3)--l-Xylp.Abbreviations CI Chemical Ionisation - COSY ¹H-¹H COrrelated SpectroscopY - COSY LR ¹H-¹H COrrelated SpectroscopY Long Range - DQF-COSY Double Quantum Filtered¹H-¹H COrrelated SpectroscopY - EI Electronic Impact - GC Gas Chromatography - HMBC Heteronuclear Multiple Bond Correlation spectroscopy - HMQC Heteronuclear Multiple Quantum Correlation spectroscopy - HOHAHA HOmonuclear HArtmann-HAhn spectroscopy - HPLC High Performance Liquid Chromatography - ³J_H.H vicinal spin-spin coupling constants - LAM LipoArabinoMannan - LOS LipoOligoSaccharide - MS Mass Spectrometry - FAB/MS Fast Atom Bombardment-Mass Spectrometry - ¹H- or¹³C- NMR proton or carbon Nuclear Magnetic Resonance - PBS Phosphate Buffered Saline - PheG1 K-I Major phenolic glycolipids fromM. kansasii - RCT-1, -2, -3 relayed coherence transfer 1 step, 2 steps, 3 steps - ROESY Rotative frame Overhauser Effect SpectroscopY - Sugars Fucp: fucopyranose - Galp galactopyranose - Glcp glucopyranose - hexp hexopyranose - Rhap rhamnopyranose - Xylp xylopyranose - TLC Thin Layer Chromatography - TMS Tri Methyl Silyl     

Phosphate-limited growth of Chromatium vinosum in continuous culture

Chromatium vinosum DSM 185 was grown in continuous culture at a constant dilution rate of 0.071 h^-1 with sulfide as the only electron donor. The organism was subjected to conditions ranging from phosphate limitation (S _R-phosphate=2.7 M and S _R-sulfide=1.8 mM) to sulfide limitation (S _R-phosphate=86 M and S _R-sulfide=1.8 mM). At values of S _R-phosphate below 7.5 M the culture was washed out, whereas S _R-phosphate above this value resulted in steady states. The saturation constant (K ) for growth on phosphate was estimated to be between 2.6 and 4.1 M. The specific phosphorus content of the cells increased from 0.30 to 0.85 mol P mg^-1 protein with increasing S _R-phosphate. The specific rate of phosphate uptake increased with increasing S _R-phosphate, and displayed a non-hyperbolic saturation relationship with respect to the concentration of phosphate in the inflowing medium. Approximation of a hyperbolic saturation function yielded a maximum uptake rate (V _max) of 85 nmol P mg^-1 protein h^-1, and a saturation constant for uptake (K _t) of 0.7 M. When phosphate was supplied in excess 8.5% of the phosphate taken up by the cells was excreted as organic phosphorus at a specific rate of 8 nmol P mg^-1 protein h^-1.Non-standard abbreviations BChla bacteriochlorophyll a - D dilution rate; _max, maximum specific growth rate - maximum specific growth rate if the substrate were not inhibitory - K saturation constant for growth on phosphate - V _max maximum rate of phosphate uptake - K _i saturation constant for phosphate uptake - K _i inhibition constant for growth in the presence of sulfide - S _R concentration of substrate in the inflowing medium     

Biosynthesis of RNA polymerase in Escherichia coli

Summary In spite of the generally well-coordinated synthesis of RNA polymerase core enzyme subunits (, and ) in Escherichia coli, a situation was found during the growth transition from exponential to stationary phase in which this coordination was broken (the order of differential repression being ; Kawakami et al. (1979)). The present study indicates that, during a certain period of the growth transition, twice as much subunit is synthesized as subunit and the overproduced subunit accumulates as the assembly intermediate ₂ complex, which is rapidly and preferentially degraded.Two independent factors, i.e., carbon source down-shift and oxygen depletion, were examined separately for their influence on the coordinated regulation of the synthesis of RNA polymerase subunits. The depletion of glucose added as a sole carbon source was accompanied by repression of the synthesis of all core enzyme subunits, while under the same conditions the differential rate of subunit synthesis increased. In contrast, the sudden ending of the oxygen supply resulted in specific repression of the synthesis of only and subunits but not of and subunits. The latter result may be explained by the autogenous repression of the rpoBC genes by a temporal increase in the amount of unused cytoplasmic RNA polymerase.Paper XI in this series is Kawakami and Ishihama (1980)     

Factors effecting adventitious shoot regeneration from leaf explants of quince (Cydonia oblonga)

A procedure for adventitious shoot regeneration from leaf explants of quince (Cydonia oblonga Mill.) using thidiazuron (TDZ) was developed. Excised leaves of cultures grown on Murashige and Skoog (MS) medium containing 5 M benzyladenine (BA) and 0.9% Gibco Phytagar were used. Several experiments were conducted to determine optimum concentrations of thidiazuron, -naphthaleneacetic acid (NAA) and sucrose. When the medium contained 1.5 M TDZ and 2.5 M NAA, 85% of the discs regenerated shoots with an average of eight shoots per leaf disc. An incubation period of three weeks in the dark was necessary for optimum shoot regeneration. Leaves excised from four to six-week-old cultures gave a higher percent shoot regeneration than leaves from cultures older than six weeks. Regeneration percentages were significantly reduced when sucrose concentration in the medium was less than 3%. A significantly higher percentage of shoots regenerated when leaf discs were placed on the regeneration medium abaxial side down as compared to the adaxial side.Regenerated shoots were cultured on MS medium containing 5 M BA and rooted on half-strength MS medium containing 10 M NAA. Rooted plantlets were acclimatized to greenhouse conditions for evaluation of any somaclonal variation. The importance of these findings are discussed in relation to in vitro improvement of plants.Abbreviations BA benzyladenine - MS Murashige & Skoog (1962) salt mixture - NAA -naphthaleneacetic acid - TDZ thidiazuron (N-phenyl-N'-1,2,3,-thiadiazol-5-ylurea) Approved for publication by the Director, West Virginia Agric. and For. Expt. Sta. as Scientific Article No.2346     

Diurnal changes in leaf gas exchange and chlorophyll fluorescence in tropical tree species with contrasting light requirements

Interspecific ecophysiological differences in response to different light environments are important to consider in regeneration behavior and forest dynamics. The diurnal changes in leaf gas exchange and chlorophyll fluorescence of two dipterocarps, Shorea leprosula (a high light-requiring) and Neobalanocarpus heimii (a low light-requiring), and a pioneer tree species (Macaranga gigantea) growing in open and gap sites were examined. In the open site, the maximum net photosynthetic rate (P_n), photosystem II (PSII) quantum yield (; F/Fm), and relative electron transport rate (r-ETR) through PSII at a given photosynthetic photon flux density (PPFD) was higher in S. leprosula and M. gigantea than in N. heimii, while non-photochemical quenching (NPQ) at a given PPFD was higher in N. heimii. The maximum values of net photosynthetic rate (P_n) in M. gigantea and S. leprosula was higher in the open site (8–11 mol m^–2 s^–1) than in the gap site (5 mol m^–2 s^–1), whereas that in N. heimii was lower in the open site (2 mol m^–2 s^–1) than in the gap site (4 mol m^–2 s^–1), indicating that N. heimii was less favorable to the open site. These data provide evidence to support the hypothesis that ecophysiological characteristics link with plants regeneration behavior and successional status. Although P_n and stomatal conductance decreased at midday in M. gigantea and S. leprosula in the open site, both r-ETR and leaf temperature remained unchanged. This indicates that stomatal closure rather than reduced photochemical capacity limited P_n in the daytime. Conversely, there was reduced r-ETR under high PPFD conditions in N. heimii in the open site, indicating reduced photochemical capacity. In the gap site, P_n increased in all leaves in the morning before exposure to direct sunlight, suggesting a relatively high use of diffuse light in the morning.     

Growth yields and growth rates of Desulfovibrio vulgaris (Marburg) growing on hydrogen plus sulfate and hydrogen plus thiosulfate as the sole energy sources

Desulfovibrio vulgaris (Marburg) was grown on H₂ plus sulfate and H₂ plus thiosulfate as the sole energy sources and acetate plus CO₂ as the sole carbon sources. Conditions are described under which the bacteria grew exponentially. Specific growth rates () and molar growth yields (Y) at different pH were determined. and Y were found to be strongly dependent on the pH. Highest growth rates and molar growth yields were observed for growth on H₂ plus sulfate at pH 6.5 (=0.15h^-1; Y _{SO 4} ^2- =8.3g·mol^-1) and for growth on H₂ plus thiosulfate at pH 6.8 (=0.21h^-1; Y _{S 2}O ₃ ² =16.9g·mol^-1).The growth yields were found to increase with increasing growth rates: plots of 1/Y versus 1/ were linear. Via extrapolation to infinite growth rates a Y _SO4 ^2- /max of 12.2g·mol^-1 and a YS₂O ₃ ^2- /max of 33.5g·mol^-1 was obtained.The growth yield data are interpred to indicate that dissimilatory sulfate reduction to sulfide is associated with a net synthesis of 1 mol of ATP and that near to 3 mol of ATP are formed during dissimilatory sulfite reduction to sulfide.     

Trapping efficiency of three carnivorous Pinguicula species

Summary In situ trapping efficiencies of Pinguicula alpina L., P. villosa L., and P. vulgaris L. were compared with each other and with those of artificial traps at a subarctic site in northern Sweden. P. vulgaris had the highest trapping efficiency i.e., 21–37 g prey trapped cm^-2 day^-1 and apparently has some means of attracting prey. The other two species trapped about 14–18 g cm^-2 day^-1, a value similar to that of paper traps mimicing plant leaves. By weight, Nematocera and Collembola were the dominant groups trapped by P. alpina. P. villosa trapped mainly Collembola, while small Nematocera dominated the prey caught by P. vulgaris. Mites (Acarina) were caught in high numbers but contributed only a small part of the total captured biomass owing to their low weight.     

Host plant suitability of a recently naturalized thistle Cirsium vulgare (Asteraceae) for a phytophagous ladybird beetle,Epilachna pustulosa (Coleoptera: Coccinellidae)

The phytophagous ladybird beetle, Epilachna pustulosa Kôno occurs mainly on the thistle Cirsium kamtschaticum Ledeb. In recent years, we have confirmed feeding and oviposition by E.pustulosa, and some degree of larval development of this beetle, on a naturalized congeneric thistle, Cirsium vulgare (Savi) Tenore. In this study, we assessed the host suitability of C.vulgare for E.pustulosa, using larval rearing and simple food choice tests, by comparing the performance on, and preference for, their legitimate host C.kamtschaticum. All experiments were initiated in July, when the utilization of C.vulgare by E.pustulosa became obvious. For larval performance, E.pustulosa showed a lower eclosion rate, shorter developmental duration and smaller body size when reared on C.vulgare than on C.kamtschaticum. Cirsium vulgare appeared to be a less adequate larval food than C.kamtschaticum. Adult feeding preference was altered seasonally; females preferred C.kamtschaticum to C.vulgare in a food choice test conducted in early July, whereas they showed the opposite preference in tests conducted in mid and late July. The utilization of C.vulgare by E.pustulosa appeared to be induced by qualitative deterioration of C.kamtschaticum leaves in July, which resulted in increased dispersion of adult beetles.     

Somatic embryogenesis through pseudo-bulblet transverse thin cell layer of Lilium longiflorum

Somatic embryogenesis was achieved directly from pseudo-bulblettransverse thin cell layers (tTCL) of Lilium longiflorum.Embryo-like structures (globular embryos) were obtained from different sizeexplants of pseudo-bulblet tTCLs after 45 days culture on Murashige and Skoog,1962 (MS) medium containing 5.4 M naphthalene acetic acid(NAA)and 1.1 M thidiazuron (TDZ). The embryo-like structures werethen isolated and mass proliferated on MS medium, containing 5.4M NAA and 0.4 M TDZ, every 45 days. A0.8–1.0 mm thick explant was shown to be optimal forobtaining the highest number of embryo-like structures. For plant regenerationthese structures were transferred to hormone-free MS medium with 30g/l sucrose. All of these structures formedplantlets after 90 days culture.     

Life Cycle of the Tick Haemaphysalis Leporis-palustris (Acari: Ixodidae) Under Laboratory Conditions

The life cycles of two separate populations (colonies A and B) of the rabbit tick, Haemaphysalis leporis-palustris, were studied under laboratory conditions. Domestic New Zealand rabbits, Oryctolagus cuniculus, and wild rabbits, Sylvilagus brasiliensis, were used as hosts for ticks from colony B and only O. cuniculus rabbits were used as hosts for ticks from colony A. Developmental periods were observed in an incubator at 27±1°C and RH 90±5%. Larvae from colonies A and B fed for 8.0±3.7 days and 8.5±1.3 days, respectively, on O. cuniculus. On S. brasiliensis larvae from colony B fed for 7.2±1.3 days. Nymphs from colony A fed for 8.1±1.4 days on O. cuniculus and nymphs from colony B fed for 8.1±1.0 days on S. brasiliensis. Only one engorged nymph from colony B was recovered from O. cuniculus. Females from colony A fed for 20.9±5.9 days on O. cuniculus and females from colony B fed for 18.6±2.4 days on O. cuniculus and 18.7±3.7 days on S. brasiliensis. Engorged larvae from colony A required 13.7±3.7 days to molt while engorged larvae from colony B required 11.8±3.0 and 11.5±1.8 days to molt, after having fed on O. cuniculus and S. brasiliensis, respectively. Engorged nymphs from colonies A and B required 16.3±1.9 days and 14.7±1.4 days to molt, respectively. Engorged females from colonies A and B required 4–7 and 3–5 days, respectively, to start oviposition. Mean egg incubation periods lasted for 33–34 days. For ticks from colony B, host species accounted for significant differences (p<0.05) in larval and nymphal feeding periods, oviposition weights and CEIs. Significant differences (p<0.05) between the two colonies when ticks fed on O. cuniculus were observed for larval and nymphal feeding and premolt periods, engorged female and oviposition weights and conversion efficiency indexes (CEI). S. brasiliensis were always a more suitable host for H. leporis-palustris than O. cuniculus. Significantly more larvae and nymphs engorged and molted when fed on S. brasiliensis (p<0.001). Females fed S. brasiliensis were more successful to lay fertile eggs and showed the highest engorged and egg mass weights, and the highest CEIs. Data of H. leporis-palustris fed on wild rabbits (one of its natural host species) are reported for the first time.     

Evidence from lectin-binding studies for abnormal glycosylation ofβ-hexosaminidase in the leukaemic cell-line CCRF/CEM

The lectin affinities of -N-acetyl-d-hexosaminidase (E.C.3.2.1.52) from an acute lymphoblastic leukaemic cell-line (CCRF/CEM), a non-malignant lymphoblastic cell-line (SM1) and normal human fibroblasts were studied for both mature and precursor forms of the enzyme. Four immobilised lectins concanavalin A-Sepharose wheat germ agglutinin-Agarose,Ricinus communis agglutinin I-Agarose,Phaseolus vulgaris erythroagglutinin-Agarose and a column of serotonin-Sepharose were used. The activities of -hexosaminidase from fibroblasts and SM1 cells generally behaved similarly while the CCRF/CEM enzyme exhibited different binding patterns. Differences were also noted between precursor and mature enzyme from each cell type consistent with changes in glycosylation between the precursor form and the mature form appearing in the lysosome. These results suggest that changes in the glycosylation of -hexosaminidase, and possibly other lysosomal enzymes, may be associated with malignancy.Abbreviations Con A concanavalin A-Sepharose - RCA-I Ricinus communis agglutinin I-Agarose - WGA wheat germ agglutinin-Agarose - PHA-E Phaseolus vulgaris erythroagglutinin-Agarose - SER serotonin-Sepharose: non-T - non-B ALL non-T, non-B cell acute lyphoblastic leukaemia - 4-MU-GLcNAc 4-methylumbelliferyl 2-acetamido-2-deoxy--D-glucopyranoside     

Kinetics of sulfate uptake by freshwater and marine species ofDesulfovibrio

Apparent half-saturation constants (K _m) and maximum uptake rates (V _max) for sulfate were determined in four species ofDesulfovibrio of freshwater and marine origin using a³⁵S-sulfate tracer technique. The lowerstK _m (5 M) was found in the freshwater speciesDesulfovibrio vulgaris (Marburg) and the highestK _m (77 M) in the marine speciesDesulfovibrio salexigens. Maximum specific rates of sulfate uptake (i.e.,V _max) were proportional to the growth rates observed in batch cultures. The halophilicDesulfovibrio salexigens did not change itsK _m andV _max between 1 and 6,000 M SO ₄ ^2- , and apparently did not induce a low-affinity uptake system at high sulfate concentrations. The low half-saturation constants measured for sulfate uptake explain why high rates of bacterial sulfate reduction occur in surface sediments of freshwater lakes, and why sulfate reduction can be a quantitatively important process in anaerobic carbon mineralization in low-sulfate environments. The results shows that extremely low sulfate concentrations must occur before sulfate reduction is completely outcompeted by methanogenesis.Abbreviations MPB methane producing bacteria - SRB sulfate reducing bacteria     

Effects of Bt maize-fed prey on the generalist predator <Emphasis Type="Italic">Poecilus cupreus</Emphasis> L. (Coleoptera: Carabidae)

We investigated the effects of transgenic maize (Zea mays) expressing Bacillus thuringienses toxin (Bt maize) on larval and adult Poecilus cupreus carabid beetles in laboratory studies. In no-choice trials, neonate P. cupreus larvae were fed exclusively with Spodoptera littoralis caterpillars, which had been raised on Bt maize. S. littoralis raised on conventional maize or high quality Calliphora sp. pupae were fed to the beetle larvae in two control treatments. Bt-maize-fed caterpillar prey increased mortality to 100 within 40days. The experiment was repeated with 10-day-old beetle larvae. Bt treatment resulted in fewer pupae than in both controls, and in a higher mortality than in the Calliphora control. S. littoralis was suitable as exclusive prey in no-choice tests, at least for 40days, although prey quality seemed to be low compared to Calliphora pupae. The observed effects are most likely indirect effects due to further reduced nutritional prey quality. However, direct effects cannot be excluded. In the second part of the study, exposure of P. cupreus to Bt intoxicated prey was examined in paired-choice tests. Adult beetles were offered a choice between different prey conditions (frozen and thawed, freshly killed or living), prey types (S. littoralis caterpillars, Calliphorasp. pupae, cereal aphids) and prey treatments (raised on Bt or conventional maize). Living prey was preferred to frozen and dead prey. Caterpillars were only preferred to fly pupae and aphids when living. Prey treatment seemed to be least important for prey selection. The tests showed that P. cupreus ingested caterpillars readily and there was no evidence of them avoiding Bt containing prey, which means exposure in the field could occur. The presented protocols are a first step towards ecological risk assessment for carabid beetles.     

Induction of ethylene formation in bean (Phaseolus vulgaris) hypocotyl segments by preparations isolated from germ tube cell walls of Uromyces phaseoli

Hypocotyl segments of Phaseolus vulgaris produce ethylene at pH 8.0 and ethane at pH 5.4. Ethylene formation, but not ethane formation, was stimulated by methionine, while -linolenic acid stimulated both ethylene and ethane formation. Detached primary leaves of var. Favorit (susceptible to Uromyces phaseoli) show no enhanced ethylene formation, whereas primary leaves from var. 017 (hypersensitive) exhibit two distinct ethylene peaks ca. 10 h and 50 h after inoculation with U. phaseoli.Cell wall preparations from uredospore germ tubes of U. phaseoli strongly stimulate ethylene formation in hypocotyl segments of the hypersensitive var. 017 but to a much lesser extent in the susceptible var. Favorit.Abbreviation UCP Uromyces Cell Wall Preparation