Uptake and distribution of calcium in rose plantlets as affected by calcium and boron concentration in culture solution

Grafted rose plantlets were grown in a controlled growth room in order to study the effect of Ca and B concentration on Ca uptake, distribution and transport to the apex. There were three Ca levels and three B levels. Root development was affected by Ca and B levels available to the roots. ⁴⁵Ca taken up was readily translocated to the scion, but accumulated in the rootstock in low-Ca plants. Translocation of Ca was increased by increasing B concentration. The relative Ca sink strength of low- and high-transpiring organs was affected by Ca and B concentrations. Increasing Ca level will increase rose growth only if B concentration is adjusted accordingly.     

Restriction of calcium uptake in normal and sickle red cells by procaine hydrochloride and P-aminobenzoic acid.

A reduced capacity for calcium uptake by human red cells after procaine hydrochloride and p-aminobenzoic acid treatment has been measured by atomic absorption spectrophotometry and X-ray microprobe techniques. Cell-associated calcium was lower by 45% and 38% in deoxygenated sickle cells pre-exposed to 10 mM procaine HCl and PABA and incubated 2 hr. at 37°C in plasma, as compared with untreated cells. Prior exposure of washed red cells to 10 mM PABA reduced the intracellular calcium level by 39% after incubation for 45 min. at 37°C with 40 μM calcium ionophore A23187. Procaine HCl was more efficient than PABA in inhibiting calcium uptake at equimolar concentrations.     

Glycolate oxidase content of microbodies as affected by nitrate

Glycolate oxidase is loosely held by microbodies obtained from etiolated barley (Hordeum vulgare L.) leaves depleted of nitrate. Defined centrifugation conditions cause the complete detachment of the enzyme from the microbodies. Addition of nitrate to these plants brings about a greater retention of glycolate oxidase by the microbodies. Synthesis of a nitrate-induced protein seems to be responsible for the enhanced retention of glycolate oxidase. Catalase, on the contrary, is strongly attached to the microbodies under all nutritional and experimental conditions considered.     

Phosphorus content and growth of fenugreek as affected by cadmium application

Changes in growth and phosphorus content in plants and seeds of fenugreek with increasing cadmium concentration was evaluated. Root length and shoot length ranged from 11.63 to 27.72 and from 9.70 to 54.78 cm, respectively. With the increasing Cd²⁺ concentration there was a significant decrease in root and shoot length, and fresh mass. Various phosphorus fractions of shoot decreased with increasing Cd²⁺ concentration except lipid P and nucleic acid P which increased at 65 and 95 d after sowing and protein P only increased at vegetative stage. In seeds (60 d after flowering) lipid P increased except at 2.5 μg(Cd²⁺) g^?1 (soil) while protein P decreased.     

Cyclic AMP content of autonomic ganglia as affected by catecholamines

The relative content of cAMP was measured in the rat ganglion nodosum, lumbar ganglia of the sympathetic trunk, the main pelvic ganglion and intramural ganglia of the heart. It was observed that the basal level of cAMP in the cardiac ganglia was lower than in other ganglia. The process of stimulation of the cAMP content by noradrenaline was most pronounced in the main pelvic and lumbar ganglia, that by dopamine in the cardiac ganglia. The catecholamines failed to alter the cAMP content in the ganglion nodosum.     

Enzyme content of plant microbodies as affected by experimental procedures

The content of specific enzymes in microbodies isolated from tobacco Nicotiana rustica, L. leaves may vary according to the procedure followed during the isolation of the organelles. The type of homogenizing medium, its ionic components and the ratio of medium to tissue during homogenization, affect the over-all yield and relative distribution of each microbody enzyme in different ways. The type of density gradient and the initial acceleration of the centrifuge rotor affect also the enzyme content of sedimenting microbodies. These observations explain some of the conflicting results obtained on the determination of the intracellular location of several enzymes.     

Monoterpene content in Origanum syriacum as affected by environmental conditions and flowering

A high content of essential oil in the foliage of two chemotypes of field-grown Origanum syriacum L. was found between August and October. The content of phenolic monoterpenes in the essential oil was low from November to January, while the content of p -cymene was high. The effect of environmental conditions and flowering on the two chemotypes was similar. Controlled experiments revealed that under long photoperiods the content of essential oils in the foliage and of phenolic monoterpenes in the oil increased, while that of p -cymene decreased. A similar effect was observed when an 8 h natural light day was extended by 8 h low-intensity incandescent light. When the 16 h day was composed of 12 h natural light, the effect on oil content and composition was intensified. Under short-day photoperiods, increasing temperature or light intensity enhanced the relative content of p -cymene, while that of phenolic monoterpenes and the γ-terpinene generally decreased. Flowering decreased the essential oil content in the leaves and the relative content of the phenolic monoterpenes in the essential oil. Since environmental conditions influence flowering, they had both direct and indirect effects on the essential oil content and composition.     

Kinetics of the inhibition of acetylcholinesterase from pigeon brain by procaine hydrochloride

The kinetic parameters of the inhibition of pigeon brain acetylchlolinesterase (AChE) by procaine hydrochloride were investigated. Procaine (0·083–1·67 mM) reversibly inhibited AChE activity (15–83 percent) in a concentration dependent manner, the IC₅₀ being about 0·38 mM. The Michaelis-Menten constant (K_m) for the hydrolysis of acetylthiocholine iodide was found to be 1·53 × 10^?4 M and the V_max was 1·06 μmol min^?1 mg^?1 protein. Dixon as well as Lineweaver-Burk plots and their secondary replots indicated that the nature of the inhibition is of the linear mixed type which is considered to be a mixture of partial competitive and pure non-competitive. The values of K_i(slope) and K_i (intercepts) were estimated as 0·14 mM and 0·22 mM respectively by the primary Dixon and by the secondary replots of the Lineweaver-Burk plot. The K_i′/K_i ratio shows that procaine has a greater affinity of binding for the peripheral than for the active site.     

Glycoalkaloid and nitrate content of potatoes as affected by method of selenium application

A comparison of two methods of selenium application, banding and foliar spray, of sodium selenite (Na₂SeO₃) on total glycoalkaloid (TGA) and nitrate nitrogen (NO₃-N) was studied during each of two consecutive years. The levels of application used were 0.0, 1.6 (0.75), 3.36 (1.5), and 5.6 (2.5) kg/ha (ppm soil). Both TGA and NO₃-N were significantly reduced by application of 1.5 and 2.5 ppm of sodium selenite. Tuber selenium levels were significantly increased at all levels of application, using either banding or foliar spray, but were well below the toxic range for human consumption. Banding resulted in greater uptake of Se, and greater decreases in TGA and NO₃-N as compared to foliar spray.     

Properties of pullulan-based blend films as affected by alginate content and relative humidity

Pullulan-sodium alginate blend films were prepared and characterized as a function of water activity (a_w). At low a_w, the incorporation of alginate into pullulan film increased the tensile strength and elastic modulus, but decreased the elongation at break of the composite films; the opposite trends were observed at elevated a_w. Above 0.43 a_w, water exerted a typical plasticization effect upon the biopolymer blends. As a_w increased from 0.23 to 0.43, an anti-plasticization effect was observed as tensile strength and elastic modulus increased. The glass transition temperature of all samples decreased substantially as aw increased from 0.23 to 0.84 due to the plasticization effect of water. Within this a_w range, one transition temperature was observed for all film specimens. The stretching vibration band of O-H was investigated using attenuated total reflection Fourier transform infrared spectroscopy to identify the various species of water interacting with the polysaccharide films.     

Adenine nucleotide content of corn roots as affected by injury and subsequent washing

The adenine nucleotide content of the 2-centimeter segments excised from tray-grown corn (Zea mays L., WF9 × Mo17) roots declines for the first hour after excision. Concomitant with the loss of adenine nucleotides is a decline in respiration and a leakage of K⁺. With continued washing, these parameters partially or completely recover and increased phosphate influx develops. Increasing the wound effect by cutting 0.5-centimeter segments gives a more rapid and pronounced degradation of adenine nucleotides and slower recovery. Conversely, the mild injury caused by submerging intact roots induces less degradation and produces greater net adenine nucleotide synthesis during recovery; adding auxin to the washing medium produces a similar result. With all treatments, there is stabilization of energy charge at about 0.85.     

Calcium binding capacity and calcium sensitive protein content in denervated frog muscles

Total and ionic calcium content, calcium binding capacity of sarcoplasmic proteins and calcium insensitive proteins were examined in atrophying leg muscles of frog after 1-5 months period of denervation. Different muscles showed different levels of atrophy and the total calcium content varied with reference to the type of muscle. Ionic calcium levels doubled in the gastrocnemius muscle after three months denervation. Calcium binding capacity of proteins and calcium insensitive proteins decreased rapidly up to four months after denervation in the gastrocnemius muscle. However no significant changes in the levels of calcium binding capacity and calcium insensitive proteins were found with reference to the type of muscle. Since total calcium content remains constant and wet muscle mass (expressed as atrophy) decreased markedly, an apparent increase in calcium concentration occurs in each muscle on denervation.     

Comparison of tetrodotoxin and procaine in internally perfused squid giant axons

Squid giant axons were internally perfused with tetrodotoxin and procaine, and excitability and electrical properties were studied by means of current-clamp and sucrose-gap voltage-clamp methods. Internally perfused tetrodotoxin was virtually without effect on the resting potential, the action potential, the early transient membrane ionic current, and the late steady-state membrane ionic current even at very high concentrations (1,000–10,000 nM) for a long period of time (up to 36 min). Externally applied tetrodotoxin at a concentration of 100 nM blocked the action potential and the early transient current in 2–3 min. Internally perfused procaine at concentrations of 1–10 mM reversibly depressed or blocked the action potential with an accompanying hyperpolarization of 2–4 mv, and inhibited both the early transient and late steady-state currents to the same extent. The time to peak early transient current was increased. The present results and the insolubility of tetrodotoxin in lipids have led to the conclusion that the gate controlling the flow of sodium ions through channels is located on the outer surface of the nerve membrane.     

Amino-acid content of leguminous proteins as affected by genetic and nutritional factors. II

Summary Quantitative analyses have been carried out on air-dried plant material in respect of the amino-acid composition as a function of condition of cultivation and selection of variety. Arginine occurs in both the varieties of clover examined and not, as was earlier reported on the basis of the paper chromatographic analysis, only in the tetraploid variety.No pronouced differences between inoculated and non-inoculated plants or between genetically different clovers were demonstrated. The total nitrogen content was higher in the inoculated plants.     

Amino acid content of leguminous proteins as affected by genetic and nutritional factors III

Summary Pea proteins have been extracted from ground peas, and albumin, vicilin and legumin have been isolated. The electrophoretic homogenity of the proteins was tested by means of free electrophoresis and the amino acid composition was determined by column chromatography.