Effects of defoliation on seed protein concentration in normal and high protein lines of soybean

Two high (NC106, NC111) and two normal (NC103, NC107) seed protein concentration lines, derived from two different recurrent selection populations of soybean (Glycine max L. Merr.) were subjected to partial defoliation at beginning seed fill (R5) under outdoor pot culture and field conditions. The aim of this study was to test the hypothesis that capacity to store N in vegetative organs and/or to mobilize that N to reproductive organs is associated with the high seed protein concentration trait. Symbiotic N₂ fixation was the sole source of N in the pot experiment and the major source of N (met > 50% of the N requirement) in the low N soil used in the field experiment. Seed protein concentration and seed yield at maturity in both experiments and N accumulation and mobilization between R5 and maturity in the pot experiment were measured. The four genotypes did not differ significantly with respect to the amount of N accumulated before beginning seed fill (R5). Removal of up to two leaflets per trifoliolate leaf at R5 significantly decreased the seed protein concentration of NC107/111 but had no effect on this trait in NC103/106. Defoliation treatments significantly decreased seed yield, whole plant N accumulation (N₂-fixation) during reproductive growth and vegetative N mobilization of all genotypes. Differences in harvest indices between the high and low protein lines accounted for approximately 35% of the differences in protein concentration. The two normal protein lines mobilized more vegetative N to the seed (average. 5.26 g plant^–1) than the two high protein lines (average. 4.28 g plant^–1). The two high seed protein lines (NC106, NC111) exhibited significantly different relative dependencies of reproductive N accumulation on vegetative N mobilization, 45% vs. 29%, in the control treatment. Whereas, NC103 with normal and NC106 with high seed protein concentration exhibited similar relative dependencies of reproductive N accumulation on vegetative N mobilization, (47% vs. 45%). Collectively, these results indicate that N stored in shoot organs before R5 and greater absolute and relative contribution of vegetative N mobilization to the reproductive N requirement are not responsible for the high seed protein concentration trait.Abbreviations DAT days after transplanting - R5 fifth reproductive stage according to Fehr and Caviness, 1977 Mention of trademark or proprietary product does not constitute a guarantee or warranty of the product by the United States Department of Agriculture and does not imply its approval to the exclusion of other products that may also be suitable.     

Properties of monovalent nickel complexes with tetraaza-macrocyclic ligands in aqueous solutions

The effects of N-alkylation on the redox potential of the couples NiLⁱ²⁺/NiLⁱ⁺, L = tetraaza-14-membered-macrocyclic ligands, and on the properties of the monovalent nickel complexes in aqueous solutions are reported for 14 complexes. The spectra and lifetimes of the NiLⁱ⁺ complexes are reported. The self-exchange rates for the couples NiLⁱ²⁺/NiLⁱ⁺ were determined. Two of the ligands were synthesized for the first time for this study. Cyclic voltammetry and pulse radiolysis were used. The results point out that: (i) N-alkylation always shifts the redox potential to a less cathodic one; this effect stems to a large degree from the decrease in the solvation energy of the complex caused by the N-alkylation of the ligand. (ii). The lifetime of the monovalent complexes is not linearly related to the redox potential of the NiLⁱ²⁺/NiLⁱ⁺ couples. (iii) The NiLⁱ⁺ complexes exist in several isomeric forms; the rate of the isomerization depends on the structure of the ligand. (iv) Different isomers of NiLⁱ⁺ may be formed when the complex NiLⁱ²⁺ is reduced by different reagents; therefore, the pulse-radiolytically formed NiLⁱ⁺ complexes might have different properties than those formed electrochemically.     

Characterization of Nine Novel Mutations in the CD40 Ligand Gene in Patients with X-Linked Hyper IgM Syndrome of Various Ancestry

X-linked immunodeficiency with hyper-IgM (HIGMX-1) is a rare disorder caused by defective expression of the CD40 ligand (CD40L) by activated T lymphocytes, resulting in inefficient T-B cell cooperation and failure of B cells to undergo immunoglobulin isotype switch. In the present work, we describe nine patients of various ancestry who bear different mutations in the X chromosome–specific CD40L gene. Two of the mutations were nonsense mutations, one each resulting in premature stop codons at amino acid residues 39 and 140. Three patients had single point missense mutations, one each at codons 126, 140, and 144. Another patient had a 4-bp genomic deletion in exon 2, resulting in a frameshift and premature termination. Three patients showed insertions, one each of 1, 2, and 4 nt, probably because of polymerase slippage, resulting in frameshift mutation and premature termination. Overall, these observations confirm the heterogeneity of mutations in HIGMX-1. However, the identification of two patients whose mutation involves codon 140 (previously shown to be altered in two other unrelated subjects) suggests that this may be a hotspot of mutation in HIGMX-1. In two additional patients with clinical and immunological features indistinguishable from canonical HIGMX-1, no mutation was detected in the coding sequence, in the 5' flanking region, or in the 3' UTR.     

A trans-acting regulatory product necessary for expression of the Drosophila melanogaster 68C glue gene cluster

The mutation I(1)npr-1 is located at cytological location 2B5 on the X chromosome in Drosophila melanogaster. We have found that this mutation causes absence of the normal product of the 2B5 locus and that it has the following phenotypes: the 68C glue puff on the third chromosome does not regress when mutant salivary glands are cultured in the presence of ecdysterone; the three 68C glue protein mRNAs are not synthesized; and a transformed Drosophila strain carrying both a normal resident 68C Sgs-3 gene and an introduced functional Sgs-3 gene with only a few kb of flanking sequences expresses neither Sgs-3 RNA if the I(1)npr-1 mutation is crossed into the stock. Thus the normal product of the I(1)npr11 gene is required for regression of the 68C puff, and the I(1)npr-1 gene product allows expression of the Sgs-3 gene by interacting, either directly or indirectly, with DNA sequences near this glue protein gene.     

Mycoplasma pneumoniae Pneumonia—Experience at a Referral Center

Mycoplasma pneumoniae pneumonia is usually a benign illness, and respiratory complications and extrapulmonary manifestations occur rarely. In this series, patients admitted to a referral hospital with this disorder had unusual symptoms, signs and findings on chest roentgenograms and laboratory studies. Pneumonia was often severe and extrapulmonary manifestations were frequent, resulting in prolonged hospital stays and illnesses. Although this extreme end of the spectrum of disease caused by M pneumoniae is not representative of this type of pneumonia as seen in outpatients, it is important to realize that patients admitted to hospital with severe, complicated pneumonia frequently have unusual manifestations of a common disease.     

Febrile Gastroenteritis Due to Salmonella thompson—Report of an Outbreak

Salmonella thompson, a common pathogen of poultry, has received scant attention as a cause of human gastroenteritis. At least 45 persons were infected with S thompson in Sacramento, California, after eating at a chicken restaurant and 38 became symptomatic. Ten required admission to hospital, and all were treated with antibiotics and improved. In 19 cases cultures of stool specimens for S thompson over a 60-day period showed slower but statistically insignificant differences in salmonellal elimination in 7 patients who received antibiotics when compared with 12 who were untreated. We report this outbreak to increase awareness of the virulence and prevalence of gastroenteritis due to S thompson.     

Surface transport properties of reticulopodia: do intracellular and extracellular motility share a common mechanism?

The reticulopodial networks of the foraminiferan protozoans Allogromia sp., strain NF, and A. laticollaris display rapid (up to 11 microns/second) and bidirectional saltatory transport of membrane surface markers (polystyrene microspheres). Electron microscopy shows that microspheres adhere directly to the reticulopodial surface glycocalyx. A videomicroscopic analysis of this phenomenon reveals that microsphere movement is typically independent of pseudopod extension/withdrawal and that particles of different sizes and surface properties display similar motile characteristics. The motile properties of surface-associated microspheres appear identical to those of saltating intracellular organelles. Indeed, in some instances the surface-attached microspheres appear transiently linked in motion to these underlying organelles. Our observations suggest that, in reticulopodia, surface transport of microspheres and intracellular transport of organelles are driven by a common mechanism.     

Regulation of accumulation and turnover of an inducible glutamate dehydrogenase in synchronous cultures of Chlorella.

Earlier studies indicated that the gene of an ammonium-inducible glutamate dehydrogenase (GDH) was inducible throughout the cell cycle and was expressible shortly after replication early in the S-phase in synchronous Chlorella cells growing at a rate of 13% per h in the absence of inducer. In the present study, synchronous cells cultured at the same growth rate in the continuous presence of inducer accumulated this enzyme in a linear manner, with a positive rate change observed late instead of early in the S-phase. At a growth rate of 26% per h, the positive rate change appeared to be displaced to 1.5 h before the S-phase in the next cell cycle. With 2'-deoxyadenosine, an in vivo inhibitor of deoxyribonucleic acid (DNA) synthesis, the magnitude of the positive rate change was shown to be proportional to the relative increase in DNA in the previous cell cycle. Collectively, these data support the idea that expression of newly replicated genes of this enzyme can be delayed into the subsequent cell cycle in cells in the continuous presence of inducer. Studies with cycloheximide indicated that the inducible GDH and another GDH isozyme were stable in fully induced cells in the absence of protein synthesis. However, after ammonium was removed from the culture medium, the activity of the inducible GDH decreased rapidly in vivo, with a half-time of 5 to 10 min at 38.5 degrees C, whereas the rate of accumulation of the other GDH isozyme did not change. Addition of cycloheximide, at the time of inducer removal, prevented this loss in activity of the inducible GDH. The inability to rescue the activity of the inducible GDH, by readdition of ammonium during the deinduction period, indicates that this enzyme probably underwent irreversible inactivation and/or proteolytic degradation.     

Influence of gender and castration on liver and CNS N-demethylation of morphine in rats1

Rats were injected with combinations of morphine-N-¹⁴CH₃ and morphine-6³H and the isotope content of the brain and liver was measured by combustion in a tissue oxidizer. The liver of intact male rats showed a significant increase in the ³H to ¹⁴C isotope ratio relative to the blood reflecting the existence of N-demethylation in this organ. This increase was not observed in the liver of either intact females or castrated males or females. Centrally, the hypothalamus, medial thalamus, and corpus striatum of both intact and castrated male and female rats exhibited increases in ³H to ¹⁴C isotope ratios indicating the presence of N-demethylation in these tissues. These results indicate that testicular hormones serve to increase the hepatic N-demethylation of morphine, but apparently reduce the comparable reaction in the CNS.     

Aerotaxis and chemotaxis ofAzospirillum brasilense: A note

Azospirillum brasilense was attracted to capillaries containing either phosphate buffer, distilled water, or saline. The number of bacteria in these capillaries was 3–4×10⁴, after 1 h of incubation. In the presence of phosphate buffer + attractants, the number of cells accumulated in the capillary increased only to 5×10⁴–1.1×10⁵ cells. It was not possible, therefore, to measure chemotaxis inA. brasilense as distinct from aerotaxis by the capillary method. Chemotaxis was observed in semi-solid agar plates and was determined by a growth band oriented towards the attractant. Positive chemotactic response was obtained with peptone, tryptone, yeast extract, amino acids, organic acids, arabinose and galactose.