Proline

Fusarium circinatum is the causal agent of pitch canker disease affecting Pinus spp. and Pseudotsuga menziesii worldwide. Under strict quarantine measures, alternative approaches for disease control are necessary. Phosphite (Phi) salts are known for their fungicidal activity and as plant resistance elicitors; however, its potential is yet to be acknowledged in the Pinus-F. circinatum model. The main aim of this study was to assess whether the application of a Phi-based commercial formulation would delay the progression of the pitch canker on Pinus radiata plants, and on the in vitro fungal growth. In vitro assays were performed using different Phi concentrations (1% and 4%) and a non-treated control (0%), and repeated in vivo using inoculated and non-inoculated plants. Plant physiological parameters and hormonal content were evaluated. Phi was effective at inhibiting in vitro mycelial growth in a dose dependent manner. Regardless of fungal inoculation, Phi application induced positi...

Growth of Erwinia chrysanthemi in media of elevated osmolarity can be achieved by the uptake and accumulation of various osmoprotectants. This study deals with the cloning and sequencing of the ousA gene-encoded osmoprotectant uptake system A from E. chrysanthemi 3937. OusA belongs to the superfamily of solute ion cotransporters. This osmotically inducible system allows the uptake of glycine betaine, proline, ectoine, and pipecolic acid and presents strong similarities in nucleotide sequence and protein function with the proline/betaine porter of Escherichia coli encoded by proP. The control of ousA expression is clearly different from that of proP. It is induced by osmotic strength and repressed by osmoprotectants. Its expression in E. coli is controlled by H-NS and is rpoS dependent in the exponential phase but unaffected by the stationary phase.

The effects of removing proline from the diet on plasma leucine and proline kinetics were investigated. After a 1-wk control period, during which young adult men received a diet containing a complete L-amino acid mixture, seven subjects were given for 4 wk a diet devoid of proline (group 1); six received a diet devoid of proline, arginine, aspartate, glutamate, and serine (group 2); and seven continued with the complete diet (group 3). At the end of the control and 4-wk periods subjects were given a continuous, (3-h fast, 5-h fed) intravenous infusion of L-[1-13C]leucine and L-[5,5-2H]proline. Plasma proline was reduced significantly, especially during the fed state, in groups 1 and 2 after the 4-wk diet periods. Small but statistically significant (P < 0.05) reductions occurred in nonoxidative leucine disappearance and leucine appearance during the fasted state in group 2. Proline fluxes decreased by approximately 50% in fasted and fed states in groups 1 and 2. Mean de novo prol...

All patients were assessed clinically at Agia Sofia Hospital in Athens. They belonged to three unrelated families from different regions of Greece. Their parents were healthy and nonconsanguineous. All pregnancies and perinatal periods were uneventful. Their ...

Adenosine administration was tested in rats with carbon tetrachloride–induced hepatic fibrosis and was able to partially prevent the enlargement of liver and spleen induced by the toxin. This amelioration of the hepatomegaly was accompanied by a 50% reduction of the liver collagen deposition and preservation of content of glycosaminoglycans. A stimulated hepatic collagenase activity is apparently the mechanism for reduction of collagen accumulation. These effects were associated with a striking improvement in liver function. Adenosine treatment did not modify the late hepatotoxic effect of the carbon tetrachloride; however, the stimulatory effect of the nucleoside on energy state appeared to counteract the drastic decreases in adenine nucleotides, ATP, ATP/ADP ratio and energy charge elicited by the hepatotoxin. Moreover, a possible beneficial action of enhanced hepatic oxygenation caused by the vasodilator properties of adenosine cannot be ruled out. Regardless of the mechanism, adenosine seems to change the cellular response to the injury induced by the hepatotoxin. (HEPATOLOGY 1990;12:242–248).

Accumulation of proline in higher plants is an indication of disturbed physiological condition, triggered by biotic or abiotic stress condition. Free proline content can increase upon exposure of plants to drought, salinity, cold, heavy metals, or certain pathogens. Determination of free proline levels is a useful assay to monitor physiological status and to assess stress tolerance of higher plants. Here we describe three methods suitable for determination of free proline content. The isatin paper assay is simple and is suitable to assay proline content in large number of samples. The colorimetric measurement is quantitative and provides reliable data about proline content. The HPLC-based amino acid analysis can be employed when concentration of all amino acids has to be compared.

Rubber tree (Hevea brasiliensis Muell. Arg.) is an important industrial crop for natural rubber production. At present, more than 9.5 million hectares in about 40 countries are devoted to rubber tree cultivation with a production about 6.5 million tons of dry rubber each year. The world supply of natural rubber is barely keeping up with a global demand for 12 million tons of natural rubber in 2020. Tapping panel dryness (TPD) is a complex physiological syndrome widely found in rubber tree plantations, which causes severe yield and crop losses in natural rubber producing countries. Currently, there is no effective prevention or treatment for this serious malady. As it is a perennial tree crop, the integration of specific desired traits through conventional breeding is both time-consuming and labour-intensive. Genetic transformation with conventional breeding is certainly a more promising tool for incorporation of agronomically important genes that could improve existing Hevea genotyp...

The humoral and hemodynamic effects of converting enzyme inhibition captopril are presented in two patients with primary hyperaldosteronism (PHA). In all, 20 patients with resistant hypertension were treated with the angiotensin converting enzyme inhibitor captopril. In 18 patients with essential or renovascular hypertension mean (+/- SEM) plasma renin activity (PRA) rose from 5.0 +/- 1.4 to 35.3 +/- 5.3 ng/ml/hr (P less than 0.01) and mean (+/- SEM) plasma aldosterone (PA) declined from 25.8 +/- 2.9 to 15.1 +/- 1.9 ng/ml (P less than 0.01) after captopril. In two patients with PHA the PRA was not stimulated by converting enzyme inhibition, although there was modest decline in PA and a temporary reduction in blood pressure. After surgical removal of aldosterone-producing adenomas, PRA responsed appropriately to captopril. These cases illustrate that a disease process can modify the response to a drug and demonstrate that, in patients with PHA, captopril does not stimulate PRA, induc...

Salinity decreases yield in arid and semi-arid areas. With increasing demand for irrigation water, alternative sources are being sought.
Seawater salinity was previously considered unusable for irrigation. However, this water can be used successfully to grow crops under
certain conditions. Amino acids is well known biostimulant which has positive effects on plant growth and yield, and significantly
mitigates the injuries caused by abiotic stresses. Therefore, in the present study, the effect of exogenously treatment amino acid on
faba bean plant growing under seawater salt stress was investigated. Reduction of salinity damage in faba bean by using a mixture
of amino acids to improve morphological and biochemical parameters, and thus raising the level of plant yield was tested. A pot
experiment was conducted to alleviate the harmful effects of seawater salinity on faba bean cv. Giza 843 by foliar spraying of an
amino acid mixture with different concentrations (0.0, 500, 1000 or 1500 mg L-1). Irrigation of faba bean plants with seawater levels
of 3.13 and 6.25 dS m-1 led to significant reductions in shoot length, number of leaves per plant, fresh and dry weight of shoots,
photosynthetic pigments, total carbohydrates, polysaccharides, nucleic acid DNA and RNA contents of faba bean leaves. Seawater
salinity induced higher contents of Na+ and Cl- and decreased contents of K+, K+:Na+, Ca2+, Mg2+ and P3+. Irrigation of faba bean
plant with different levels of seawater decreased seed yield and total dry weight per plant compared with those irrigated with tap
water. Also, total carbohydrates and total protein contents in seeds were reduced by increased seawater salinity levels. Amino acid
application as foliar spray significantly improved all the reduced parameters due to seawater stress. However, the highest level of
amino acid of 1500 mg L-1 exerted the strongest effect in alleviating the harmful effect of seawater salinity stress.

Identification of sequence motifs that favor cis peptide bonds in proteins is important for understanding and designing proteins containing turns mediated by cis peptide conformations. From 1 H NMR solution studies on short peptides, we show that the Pro-Pro peptide bond in Pro-Pro-Phe ...