Pollination biology of two species ofKielmeyera (Guttiferae) from Brazilian cerrado vegetation

The pollination biology and breeding systems ofKielmeyera coriacea andK. speciosa, two sympatric woody species common in the cerrado vegetation of C. Brazil, were studied. Both species have similar nectarless, polystemonous Papaver-type flowers which are visited by a similar spectrum of insects, though they bloom in different seasons and are thus phenologically isolated. Large carpenter bees seem to be the most important pollinators and these and other bees effect buzz pollen retrieval despite the fact that anthers are not poricidal. Both species ofKielmeyera possess strong xenogamous breeding systems. The presence of staminate flowers and andromonoecy inK. coriacea, as well as the longevity ofK. speciosa flowers are discussed as alternative strategies to improve pollination success and reproductive efficacy.     

Microfibrils are a major component of the mesangial matrix in the glomerulus of the rat kidney

Summary Certain secretory cells in the hypophysial pars tuberalis of the Djungarian hamster display marked circannual structural alterations. The present investigation deals with the immunohistochemical properties of this cell group. A distinct TSH-like immunoreactivity was found in secretory cells of this type in the pars tuberalis of animals exposed to long photoperiods, whereas under short photoperiods the TSH-like immunoreactivity was nearly absent. In the pars distalis, the number and distribution of TSH-positive cells did not differ significantly between animals maintained under long and under short photoperiods. LH-and FSH-positive cells could not be detected in the pars tuberalis, but they are clearly present in the pars distalis of both groups of hamsters. Our immunocytochemical results suggest that photoperiodic stimuli influence the secretory activity of TSH-like immunoreactive cells in the pars tuberalis. A connection with the neuroendrocrine-thyroid axis is discussed.The study was supported by the Deutsche Forschungsgemeinschaft (Wi 558/3-1, Pe 134/2-4)     

In vitro regeneration in Allium species

An attempt to induce shoot regeneration from leaf disc explants from Allium sativum L., A. porrum L., and A. schoenoprasum L. and the induction of shoot regeneration from single flower-bud receptacles in A. porrum is presented. While the regeneration rate from leaf disc explants was low, an efficient method for propagating A. porrum in vitro was obtained by cultivating single flower-bud receptacles. The shoot regeneration ability was strongly controlled by the genotype. Up to 294 shoots per leek plant could be harvested. Simultaneously the same plant could be used for seed production and bulbil formation in vivo. The efficiency of the in vitro multiplication method described allows the integration of this procedure into breeding programmes of A. porrum Abbreviations BAP 6-benzylaminopurine - 2,4-D 2,4-dichlorophenoxy acetic acid - IAA 3-indole acetic acid - NAA 2-naphtalene acetic acid     

Sperm chromosome analysis of a man heterozygous for a pericentric inversion of chromosome 20

Summary The sperm chromosomes of a man heterozygous for inv(20)(p13q11.2) were analyzed. Twenty-six sperm chromosome complements were examined, of which fourteen contained the normal chromosome, and twelve the inverted chromosome. None of the sperm complements contained a recombinant chromosome 20. The frequency of structural chromosomal aberrations unrelated to the inversion was 11.5% (3/26). Numerical aberrations were not observed. The percentages of X- and Y-bearing sperm were 56% and 44%, respectively, which was similar to the expected 11 ratio.     

Carbon and nitrogen isotope ratios in different compartments of a healthy and a declining Picea abies forest in the Fichtelgebirge,NE Bavaria

Summary Natural carbon and nitrogen isotope ratios were measured in different compartments (needles and twigs of different ages and crown positions, litter, understorey vegetation, roots and soils of different horizons) on 5 plots of a healthy and on 8 plots of a declining Norway spruce (Picea abies (L.) Karst.) forest in the Fichtelgebirge (NE Bavaria, Germany), which has recently been described in detail (Oren et al. 1988a; Schulze et al. 1989). The ¹³C values of needles did not differ between sites or change consistently with needle age, but did decrease from the sun-to the shade-crown. This result confirms earlier conclusions from gas exchange measurements that gaseous air pollutants did no long-lasting damage in an area where such damage was expected. Twigs (¹³C between-25.3 and-27.8) were significantly less depleted in ¹³C than needles (¹³C between-27.3 and-29.1), and ¹³C in twigs increased consistently with age. The ¹⁵N values of needles ranged between-2.5 and-4.1 and varied according to stand and age. In young needles ¹⁵N decreased with needle age, but remained constant or increased in needles that were 2 or 3 years old. Needles from the healthy site were more depleted in ¹⁵N than those from the declining site. The difference between sites was greater in old needles than in young ones. This differentiation presumably reflects an earlier onset of nitrogen reallocation in needles of the declining stand. ¹⁵N values in twigs were more negative than in needles (-3.5 to-5.2) and showed age- and stand-dependent trends that were similar to the needles. ¹⁵N values of roots and soil samples increased at both stands with soil depth from-3.5 in the organic layer to +4 in the mineral soil. The ¹⁵N values of roots from the mineral soil were different from those of twigs and needles. Roots from the shallower organic layer had values similar to twigs and needles. Thus, the bulk of the assimilated nitrogen was presumably taken up by the roots from the organic layer. The problem of separation of ammonium or nitrate use by roots from different soil horizons is discussed.     

Immunological correspondence between arthropod hemocyanin subunits. I. Scorpion (Leiurus, Androctonus) and spider (Eurypelma, Cupiennius) hemocyanin

The hemocyanins of the scorpions Leiurus quinquestriatus and Androctonus australis, the tarantula Eurypelma californicum (all 24-mers), and the lycosid spider Cupiennius salei (dodecamer) were dissociated into subunits, the subunits isolated and studied by two-dimensional immunoelectrophoresis for interspecific cross-reactivities. Androctonus hemocyanin yielded a pattern of 8 subunit types in agreement with data from Lamy et al. (1979, Arch. Biochem. Biophys. 193, 140-149). Leiurus hemocyanin is also composed of 8 immunologically distinct subunits which could be assigned to the pattern of Androctonus in a subunit-to-subunit correlation. The subunit designations 1 to 6 of Lamy et al. could be adopted for both scorpion hemocyanins; however, in the present communication, Lamy's subunits 3A/3B are designated as 3'/3", because we could not unequivocally decide if 3' = 3A and 3" = 3B or vice versa. The 7 subunit types a to g of Eurypelma hemocyanin could be correlated with the scorpion hemocyanin subunits as follows: a = 3', b = 5B, c = 3C, d = 5A, e = 6, f = 2, g = 4. Additional cross-reactivities were detected between e/4, and f/5A, respectively. No subunit of Eurypelma hemocyanin is homologous to scorpion 3", which could not be precipitated by anti-Eurypelma antiserum. Antiserum against Cupiennius hemocyanin precipitated subunit f of Eurypelma and subunits 2 and 5A of scorpion hemocyanin. The published models of quaternary structure and a possible subunit phylogeny of arachnidan hemocyanins are discussed in view of the present results.     

Penicillin acylase production by E. coli

Enzyme production with E. coli ATCC 11105, in a complex medium using phenylacetic acid as inducer is carried out in a stirred-tank reactor of 10 dm³ and an airlift tower-loop reactor of 60 dm³ with outer loop at a temperature of 27 °C. The optimum inducer concentration was 0.8 kg/m³, which was kept constant by fed-batch operation. The optimum of the relative dissolved O₂-concentration with regard to saturation is below 10% in a stirred-tank reactor and at 35% in a tower-loop reactor. It was kept constant by parameter-adaptive control of the aeration rate. In a stirred-tank enzyme productivity is slightly higher than in a tower-loop reactor, and much higher than in a bubble column reactor.List of Symbols CPR kg/(m³ h) CO₂-production rate - OTR kg/(m³ h) O₂-transfer rate - OUR kg/(m³ h) O₂-utilization rate - PAA phenylacetic acid (inducer) - RQ = CPR/OUR respiratory quotient - X kg/m³ cell mass concentration - _m h^–1 maximum specific growth rate     

Growth of E. coli in a stirred tank and in an air lift tower reactor with an outer loop

E. coli ATCC 11105 was cultivated in a 10-1 stirred tank reactor and in a 60-1 tower loop reactor in batch and continuous operation. By on-line measurements of O₂ and CO₂ concentrations in the outlet gas, pH, temperature, cell mass concentration X as well as dissolved O₂ concentration along the tower in the broth, gas holdup, broth recirculation rate through the loop and by offline measurements of substrate concentration DOC and cell mass concentration along the tower, the maximum specific growth rate _m , yield coefficients Y _X/S. Y _X/DOC and were evaluated in stirred tank and tower loop in batch and continuous cultures with and without motionless mixers in the tower and at different broth circulation rates through the loop. To control the accuracy of the measurements the C balance was calculated and 95% of the C content was covered.The biological parameters determined depend on the mode of operation as well as on the reactor used. Furthermore, they depend on the recirculation rate of the broth and built-ins in the tower. The unstructured cell and reactor models are unable to explain these differences. Obviously, structured cell and reactor models are needed. The cell mass concentration can be determined on line by NADH fluorescence in balanced growth, if the model parameters are determined under the same operational conditions in the same reactor.List of Symbols a, b empirical parameters in Eq. (1) - CPR kg/(m³ h) CO₂ production rate - C kg/m³ concentration - D l/h dilution rate - DOC kg/m³ dissolved organic carbon - I net. fluorescence intensity - K _S kg/m³ Monod constant - k _L a l/h volumetric mass transfer coefficient - OTR kg/(m³ h) oxygen transfer rate - OUR kg/(m³ h) oxygen utilization rate - RQ = CPR/OUR respiratory quotient - S kg/m³ substrate concentration - t h,min, s time - t _u min recirculation time - t _M min mixing time - v m³/h volumetric flow rate through the loop - X kg/m³ (dry) cell mass concentration - Y _X/S yield coefficient of cell mass with regard to the consumed substrate - Y _X/DOC yield coefficient of the cell mass with regard to the consumed DOC - Y _X/O yield coefficient of the cell mass with regard to the consumed oxygen - Z relative distance in the tower from the aerator with regard to the height of the aerated broth - l/h specific growth rate - _m l/h maximum specific growth rate Indices f feed - e outlet     

Microbial populations in wetwood of European white fir (Abies alba Mill.)

Abstract A method for extraction of microbial populations from wood samples was worked out which gave good recovery of both aerobic and anaerobic microorganisms in agar shake dilution and plating enumerations. This method was applied to the quantification of microbial populations in three European white firs ( Abies alba Mill.) which were afflicted with the European fir disease. Low numbers of aerobic microorganisms (10²−10⁴ colony- forming units (cfu) per g fresh tissue) were detected in sapwood irrespective of the degree of affliction. Anaerobic bacteria were usually 1–2 orders of magnitude less frequent. Wetwood of highly diseased firs contained significantly higher numbers of aerobic microorganisms (10⁵−10⁷), whereas the number of anaerobes was not enhanced significantly. Among the prevalent aerobic microorganisms in wetwood were Protaminobacter, Pseudomonas strains, and a yeast. In anaerobic counts from wetwood, Klebsiella and Vibrio strains predominated. The sapwood contained Bacillus, Beijerinckia, Staphylococcus , and Clostridium spp. High numbers of aerobic microorganisms were also detected in the roots and lower stem of a diseased vine plant ( Vitis vinifera L.). The importance of microbial populations in wetwood formation and disease expression is discussed.     

On the role of Ca2+-calmodulin-dependent and cAMP-dependent protein phosphorylation in the circadian rhythm ofNeurospora crassa

Summary Pulses of some Ca²⁺ channel blockers (dantrolene, Co²⁺, nifedipine) and calmodulin inhibitors (chlorpromazine) lead to medium (maximally 5–9 h) phase shifts of the circadian conidiation rhythm ofNeurospora crassa. Pulses of high Ca²⁺, or of low Ca²⁺, a Ca²⁺ ionophore (A23187) together with Ca²⁺, and other Ca²⁺ channel blockers (La³⁺, diltiazem), however, caused only minor phase shifts. The effect of these substances (A 23187) and of different temperatures on the Ca²⁺ release from isolated vacuoles was analyzed by using the fluorescent dye Fura-2. A 23187 and higher temperatures increased the release drastically, whereas dantrolene decreased the permeation of Ca²⁺ (Cornelius et al., 1989).Pulses of 8-PCTP-cAMP, IBMX and of the cAMP antagonist RP-cAMPS, also caused medium (maximally 6–9 h) phase shifts of the conidiation rhythm. The phase response curve of the agonist was almost 180° out of phase with the antagonist PRC. In spite of some variability in the PRCs of these series of experiments all showed maximal shifts during ct 0–12. The variability of the response may be due to circadian changes in the activity of phosphodiesterases: After adding cAMP to mycelial extracts HPLC analysis of cAMP metabolites showed significant differences during a circadian period with a maximum at ct 0.Protein phosphorylation was tested mainly in an in vitro phosphorylation system (with³⁵S-thio -ATP). The results showed circadian rhythmic changes predominantly in proteins of 47/48 kDa. Substances and treatments causing phase-shifts of the conidiation rhythm also caused changes in the phosphorylation of these proteins: an increase was observed when Ca²⁺ or cAMP were added, whereas a decrease occurred upon addition of a calmodulin inhibitor (TFP) or pretreatment of the mycelia with higher (42° C) temperatures.Altogether, the results indicate that Ca²⁺-calmodulin-dependent and cAMP-dependent processes play an important, but perhaps not essential, role in the clock mechanism ofNeurospora. Ca²⁺ calmodulin and the phosphorylation state of the 47/48-kDa proteins may have controlling or essential functions for this mechanism.