Effects Of Calcium Supply Research Articles

Suppressing Src-Mediated EGFR Signaling by Sustained Calcium Supply Targeting Triple-Negative Breast Cancer.

Src is emerging as a promising target in triple-negative breast cancer (TNBC) treatment because it activates survival signaling linked to the epidermal growth factor receptor. In this study, the effect of calcium supply on Src degradation was investigated to confirm underlying mechanisms and anticancer effects targeting TNBC. MDA-MB-231 cells, the TNBC cell line, were used. Calcium supply was feasible through lactate calcium salt (CaLac), and the applicable calcium concentration was decided by changes in the viability with different doses of CaLac. Expression of signaling molecules mediated by calcium-dependent Src degradation was observed by Western blot analysis and immunocytochemistry, and the recovery of the signaling molecules was confirmed following calpeptin treatment. The anticancer effect was investigated in the xenograft animal model. Significant suppression of Src was induced by calcium supply, followed by a successive decrease in the expression of epithelial growth factor receptor, RAS, extracellular signal-regulated kinase, and nuclear factor kappa B. Then, the suppression of cyclooxygenase-2 contributed to a significant deactivation of the prostaglandin E2 receptors. These results suggest that calcium supply has the potential to reduce the risk of TNBC. However, as this study is at an early stage to determine clinical applicability, close consideration is needed.

Applicability of used disposable diapers for soil amendment and the effect of calcium supply

Applicability of used disposable diapers for soil amendment and the effect of calcium supply

Effects of calcium supply on soybean plants

This paper aims to evaluate the effects that calcium application on leaves and flowers of soybean plants exerts on yield and yield components. Two experiments were carried out in the 2013/2014 crop season under field conditions. In the first experiment, two soybean cultivars – one of determinate growth habit (BMX Ativa) and another of indeterminate growth habit (BMX Alvo) – were submitted to calcium spraying with four nozzles (twin flat, twin flat fan, cone and hollow cone). In the second experiment, soybean plants (BMX Ativa cultivar) were sprayed with calcium on the leaves and flowers at R1 or R3 growth stages. Subsequently, the plants were maintained or not under a 50-percent shade protection during flowering stage. Calcium spraying on soybean leaves or flowers during the flowering stage did not increase pod set, number of seeds, or grain yield. The calcium content in soybean flowers is not affected by foliar application thereof.

RESPONSE OF PLANT GROWTH TO LOW CALCIUM CONCENTRATION IN THE NUTRIENT SOLUTION

Many studies have indicated the importance of calcium in fruit disorders. This nutrient is often applied in the nutrient solution in relatively high amounts throughout the crop season, usually without taking into account the physiological stage of the plant. Our study aimed to determine the effect of calcium supply on growth of young, vegetative tomato plants. The experiment was carried out in a growth chamber under fully controlled climate conditions. Treatments consisted of four periods of 1, 3, 7 or 14 days of low calcium (0.5 meq l-1) compared with the control (9 me l-1). Plant dry matter content, total leaf area, leaf dry matter and specific leaf area were not affected after 14 days of low Ca supply. Ca concentrations in young leaves, stem, and roots were quickly reduced after only 1 day of low-Ca. After 14 days, Ca concentration in all plant organs (leaves, stems and roots) was reduced by approximately 70% compared to control plants. Stomatal regulation was not affected by this level of calcium stress as leaf transpiration in treated plants was similar to control plants with the same leaf area. Our data show that calcium supply and consequently Ca concentration in the plant can be reduced drastically without any adverse effect on growth.

Effect of calcium supply on the physiology of fruit tissue in ‘Andesu’ netted melon

SummaryFruit development and physiological traits were evaluated in ‘Andesu’ netted melon plants grown with and without calcium. Calcium exclusion accelerated softening, alcoholic fermentation and ethylene evolution of fruit compared with those supplied with calcium, but the opposite trend occurred with sucrose accumulation. A significant difference of calcium concentrations in the fruit between treatments was observed at the developing stage of the fruit (P<0.05), but the difference became smaller as fruit matured. In the mesocarp tissue from the basal hemisphere, calcium concentrations in the NaCl soluble fraction at ripe fruit stage differed significantly (P<0.05) between calcium treatments but no significant difference was detected in the inner mesocarp of the distal hemisphere. Calcium exclusion did not lead to the development of water-soaked symptoms in the mesocarp tissue of ripe fruit. Uronic acid concentrations in ionically bound pectin fraction did not differ between calcium treatments throughout fruit development. In covalently-bound pectin fraction, however, uronic acid concentration of ripe fruit was significantly lower in calcium-excluded plants than in calcium-supplied plants (P<0.05). Our results suggest that: first, accelerated fruit softening under calcium deficient conditions might result from promoted ethylene evolution rather than from the shortage of ionically-bound calcium in cell walls, second, calcium deficient condition does not necessarily lead to water-soaked symptoms in tissue of ‘Andesu’ melon fruit.

Response of sweet potato cultivars to acid soil infertility factors. II. Effects of calcium supply and soluble aluminium on early growth

Good growth in acid soils suggests that sweet potato may be tolerant of acid soil infertility factors such as Al toxicity or Ca deficiency. In a conventional solution culture experiment, 4 cultivars responded positively when solution Ca concentration was increased from approximately 4 to 1300 □М. However, a subsequent flowing solution culture (FSC) experiment showed no significant (P &gt; 0.05) differences in growth by most of the 15 cultivars studied when solution Ca concentration was increased from 45 to 400 □М. Hence, it was concluded that sweet potato could be fairly tolerant of low Ca supply. In contrast, soluble Al markedly decreased growth of the 15 sweet potato cultivars studied. The results of the present study indicate that Al rather than low Ca supply would be more important in limiting sweet potato growth in acid soils. Furthermore, tolerance to low Ca and soluble Al appears to be linked in sweet potato. These results highlight the importance of selecting sweet potato cultivars for specific soil conditions such as soil acidity.

Effect of Calcium Supply on Aluminium-Induced Callose Formation, its Distribution and Persistence in Roots of Soybean ( Glycine max (L.) Merr.)

Summary Inhibition of root elongation and induction of callose formation are sensitive responses of soybean (Glycine max (L.) Merr.) roots to aluminium (Al). As early as 30 min after supply of 50 μM Al in solution culture, callose increased in the very root tip. There was a decrease in callose along the root axis from the apex to the base when roots were exposed to Al for up to 8 h. Short-term exposure of roots to Al revealed that the callose concentration in root tips remained constant for several hours after transfer to Alfree nutrient solution. A substantial decomposition of callose became apparent only after 22 h. New growth of formerly Al-treated roots showed no elevated callose levels. Increasing the Ca (CaSO4) supply from 20 to 1500 μM enhanced root elongation, especially in the presence, but also in the absence of 25 μM Al at pH 4.5. Al-induced callose formation first increased and then decreased with increasing Ca supply. There was a close quadratic relationship between Al-induced inhibition of root elongation and callose formation for Ca supplies between 50 and 1500 μM. Maximum inhibition of root growth and enhancement of callose formation by Al occurred between 50–100 μM Ca. However, the lowest Ca supply of 20 μM did not fit into this pattern: Al-induced callose was much lower than predicted, indicating a Ca requirement for callose formation. Root growth but not the callose concentration in root tips could be related to Al3+ or Ca2+ activities of the nutrient solution.

Effects of calcium supply on uptake of calcium and selected mineral nutrients by tropical food legumes in solution culture

Six tropical food legumes, peanut (Arachis hypogaea (L.) cv. Red Spanish), pigeonpea (Cajanus cajan (L.) Millsp. cv. Royes), guar (Cyarnopsis tetragonoloba (L.) Taub. cv. Brooks), soybean (Glycine max (L.) Merr. cv. Fitzroy), and cowpea (Vigna unguiculuta (L.) Walp. cv. Vita 4 and CPI 282 15) were grown for 20 days at six constant solution calcium concentrations (2, 12, 50, 100,500 and 2500 8M ) in flowing solution culture at pH 5.5 � 0.1, with adequate inorganic nitrogen and controlled basal nutrient concentrations. Increases in solution calcium concentration from 2 to 12 8M generally increased rates of absorption of nitrogen, phosphorus, potassium, manganese and zinc, and rates of transport of magnesium and iron to plant tops. These increases in nutrient absorption and transport rates were associated with the alleviation of severe calcium deficiency. Further increases in solution calcium concentration from 12 to 2500 8M generally had no effect on potassium absorption rate, but increased absorption rates of nitrogen (by 20-130%), and phosphorus (by 90-500%), and decreased those of manganese and zinc; it also decreased rates of transport of iron and magnesium to plant tops. With guar, rates of phosphorus absorption at &lt;2500 8M calcium were too low to maintain adequate concentrations of phosphorus in tops for maximum growth. With the remaining legumes, rates of zinc absorption at 12 8M calcium were high enough for plants to accumulate excessive concentrations of zinc (347-479 mg kg-1) in their tops. These results are discussed in relation to the adaptation of tropical food legumes to soils with low concentrations of calcium in the soil solution and the response of legumes to calcium or lime applications.

Einfluß des Calcium‐Angebotes auf Wachstumsrate und Calcium‐Gehalt von Kartoffelknollen

Effect of calcium supply on growth rate and calcium content of potato tubers..Using potato plants in water culture with a constant calcium supply to the roots, a study was made of the influence of additional supply of calcium to the tuber surface on growth rate and calcium content of the tubers.Under conditions of high relative humidity around the tubers the calcium nutrition of the tubers was exclusively dependent on the calcium supplied to the tuber surface („exogenous calcium”︁). With a high level of exogenous Ca the growth rate of the tubers was high and the rate of uptake of Ca was proportional to the tuber growth. With a low level of exogenous Ca the growth rate declined to a lower but constant value. In absence of exogenous supply of Ca the growth rate of the tubers declined gradually until growth ceased. Cessation of tuber growth occurred when the Ca content decreased below 0,36 mg Ca per g dry matter for smaller tubers and below 0,14 mg Ca per g dry matter for larger tubers.Severe Ca deficiency in potato tubers causes necrosis at the tuber apex.

The effect of calcium supply on bur set and seed formation in subterranean clover (Trifolium subterraneum L.)

In a glasshouse experiment subterranean clover plants were grown in soil at various levels of calcium nutrition. The developing burs were buried in separate soil containers to which no nutrients, calcium sulphate, calcium carbonate, or potassium sulphate were applied. When subterranean clover was growing in soil low in calcium, top yield was little affected; but bur and seed formation were greatly reduced. However, when the reflexed flowers were buried in soil to which a calcium salt had been added, bur and seed yield increases of up to 500% were obtained The increase in seed yield resulted from a greater percentage of flowers forming bur, more seed per bur, heavier seed, and less rotten seed. Similar results were obtained in a second glasshouse experiment in which a different soil was used to grow the clover. The beneficial effect of calcium ions around the developing bur was independent of the associated anions, or of the soil pH; nor could it be produced by the substitution of potassium or magnesium for calcium. It seems likely that commercial seed yields and subterranean clover persistence in many areas may be reduced by calcium deficiency in apparently lush healthy pastures. The similarity of this disorder to calcium deficiency in peanuts suggests that other crop and pasture species forming buried seed may also be especially susceptible.