Jasmonic acid alleviates negative impacts of cadmium stress by modifying osmolytes and antioxidants in faba bean (Vicia faba L.)

We examined the role of jasmonic acid (JA) in faba bean under cadmium (Cd) stress, which reduces the growth, biomass yield, leaf relative water content (LRWC) and pigment systems. Hydrogen peroxide (H₂O₂) and lipid peroxidation (malondialdehyde [MDA]) levels increased by 2.78 and 2.24-fold, respectively, in plants under Cd stress, resulting in enhanced electrolyte leakage. Following foliar application to Cd-treated plants, JA restored growth, biomass yield, LRWC and pigment systems to appreciable levels and reduced levels of H₂O₂, MDA and electrolyte leakage. Proline and glycine betaine concentrations increased by 5.73 and 2.61-fold, respectively, in faba bean under Cd stress, with even higher concentrations observed following JA application to Cd-stressed plants. Superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase levels rose by 87.47%, 130.54%, 132.55% and 37.79%, respectively, with Cd toxicity, with further enhancement of antioxidant activities observed following foliar application of JA. Accumulation of Cd in roots, shoots and leaves was also minimized by external supplementation of JA. In conclusion, JA mitigates the negative impacts of Cd stress in faba bean plants by inhibiting the accumulation of Cd, H₂O₂ and MDA, and by enhancing osmolyte and antioxidant activities that reduce oxidative stress.     

Effect of cannabis oil on growth performance,haematology and metabolism of Nile Tilapia Oreochromis niloticus

Cannabis sativa is a plant that produces an oil with psychoactive and stress reduction effects and thus illegal in many nations. Lately, the beneficial properties of the plant extract are becoming better understood and perceptions are changing. As the aquaculture industry matures from a primitive extensive pond system to an industrialized intensive system, fish stress and disease incidence are increasing, with negative economic results. A nutritional ingredient that could reduce stress and disease incidence in aquacultured fish would thus be opportune. In the present work we investigated whether ether extracted cannabis oil would relieve stress, improve growth and feed conversion, and/or improve haematological indicators of disease resistance. Three diets were made to contain either soy oil, industrial hemp oil or cannabis oil and offered to tilapia for 8 weeks. At termination, survival, growth, feed conversion and blood parameters were assessed. Fish were returned to their tanks, offered the same feeds as during the experiment and respiration assessed. Cannabis extract was found to increase metabolism and thus increase feed conversion. On the other hand, cannabis had no effect on blood cell counts, total plasma protein, haematocrit or lysozyme activity. Results thus suggest that cannabis does not improve immune response of tilapia or body composition but does reduce growth rate by increasing metabolic rate.     

Effect of soil moisture on the release of alachlor from alginate-based controlled-release formulations

The release of alachlor from controlled-release formulations (CRFs) based on alginate-montmorillonite matrices into aqueous polyethylene glycol (PEG) solutions of different concentrations and into a soil at different moisture contents was studied. In distilled water and in PEG-containing solutions displaying -0.1 MPa potential and up, the beads imbibe water and swell. The ensuing increase in weight is about 5%, and the increase in the bead's diameter is about 10%. At water potentials of -0.5 MPa and lower, loss of weight and shrinkage of the beads were observed. The changes in weight and diameter of the alginate-clay beads incubated in a Hamra loamy sand soil at 26.5% moisture content (w/w; -0.18 MPa) were similar to those observed in PEG solutions of >-0.5 MPa moisture potential. The weight and diameter losses observed in the drier soils (12.0 and 7.1% water content; -0.49 and -1.11 MPa) were similar to those in the more concentrated PEG solutions. A decrease in the rate of release of the active ingredient from the beads into soil was observed as the water potential decreased (drier soils). The release of the active ingredient from the investigated CRFs displayed a linear relationship to the square root of time, suggesting a diffusion-controlled-release rate. Data extracted from this relationship enabled the formulation of a mathematical model that correlates rate of release to water content.     

Effects of Zeolite and Zinc on Quality of Canola (Brassica napus L.) Under Late Season Drought Stress

The research was performed to investigate the effect of zeolite and zinc on the qualitative characteristics of canola cultivars at different moisture regimes. Factorial split plot experiment was performed on the basis of the randomized complete blocks design with three replications in Karaj, Iran. The treatments were: 1) irrigation (I): complete (normal irrigation) (I₁), and restricted irrigation (I₂) applied at the pod formation stage, 2) zeolite (Z): 0 (Z₁), and 15 t ha^?1 (Z₂), and 3) Zn: zinc sulfate concentrations of 0%, 0.1%, and 0.2% (Zn_1, Zn_2, and Zn₃) on Opera, Licord, and RGS003 cultivars. The highest rate of all studied traits was obtained by applying Z₂Zn₂ (15 ton ha^?1 zeolite and 0.1% zinc sulfate) in both irrigation regimes. Opera cultivar in normal irrigation and RGS003 cultivar in stress conditions had the highest yield and yield components, oil yield, and oil content.     

Stimulation of insulin and glucagon synthesis in rat Langerhans islets by malathion in vitro: Evidence for mitochondrial interaction and involvement of subcellular non-cholinergic mechanisms

We examined the effects of malathion, an organophosphorus (OP) insecticide, on glucagon, C-peptide, and insulin content or secretion from isolated rat Langerhans islets in vitro. Islets were isolated from the pancreas of rats by standard collagenase digestion, separation by centrifugation, and hand-picking technique. Then islets were cultured in medium and supplemented with various concentrations of malathion (25, 125, and 625 μg/ml) for 1, 3, and 5 h. In vitro exposure to malathion increased insulin and C-peptide contents at doses of 25, 125, and 625 μg/ml following 5 h incubation as compared to control. All doses of malathion increased glucagon content after 3 and 5 h as compared to control. Increase of the glucagon content at all doses in the fifth hour was higher than that of third hour. Malathion also decreased 2.8 and 16.7 mM glucose-stimulated insulin secretion at all doses after 30 min as compared to control.It is concluded that malathion reduce insulin exocytose in a short time (first hour) but after a long time (e.g., 5 h), the content of insulin is increased by compensating mechanisms such as resynthesize of insulin or aggregation of insulin. The present in vitro study for the first time proposes the involvement of subcellular non-cholinergic mechanisms in malathion-induced changes in Langerhans islets insulin and glucagon.     

Induction of insulin resistance by malathion: Evidence for disrupted islets cells metabolism and mitochondrial dysfunction

Hyperglycemia is observed with exposure to organophosphorus (OP) pesticides. The aim of this study was to investigate the effects of malathion on secretion of insulin from rat pancreatic islets in vitro and in vivo. Malathion was administered through food for 4 weeks at concentrations of 100, 200, and 400 ppm. For in vivo experiment, at the end of treatment, blood sample was obtained and plasma was separated. For in vitro experiment, the treated rats were anesthetized and underwent a laparatomy. The common bile duct was cannulated and the pancreas distended by injecting of cold collagenase V using peristaltic infusion pump. Islets were then hand picked under a stereomicroscope and cultured in the presence of various doses of glucose and KCl. Malathion at doses of 200 and 400 ppm increased plasma glucose and insulin concentrations and lowered activity of erythrocyte acetylcholinesterase. The isolated islets from pretreated animals with malathion 200 and 400 ppm showed lower glucose-stimulated insulin secretion while no change was observed in the presence of KCl. Light microscopic examination revealed that malathion causes patchy degenerative changes in pancreatic islets. Combination of in vivo and in vitro findings suggests that malathion induces a kind of insulin resistance that cannot overwhelm hyperglycemia. This action of malathion is mediated through disruption of islets mitochondrial function.     

Effect of egg parasitoid density on the population suppression of Sunn Pest, Eurygaster integriceps (Hemiptera: Scutelleridae), and its resulting impact on bread wheat grain quality

The impact of the density of Sunn Pest egg parasitoids, Trissolcus grandis Thomson (Hymenoptera: Scelionidae), at three levels of Sunn Pest, Eurygaster integriceps Puton (Hemiptera: Scutelleridae), infestation was assessed on bread wheat variety Cham 6 in screened cages in the field for percentage of egg parasitism and grain quality. Percent parasitism ranged from 60.1 to 83.9%. No statistically significant differences were detected at parasitoid densities of 1, 2, or 3 insects per square meter at Sunn Pest densities of 2 or 4 insects per square meter. The quality of grain collected from all Sunn Pest infested cages without egg parasitoids was unacceptable for baking purposes and was significantly lower than grain from both non-infested plots and plots where either two or three egg parasitoids were present. The abundance of egg parasitoids in Al Hassakeh province in Syria was also determined. Egg parasitism was observed 1 week after the initiation of Sunn Pest oviposition and ranged between 22 and 59% in non-insecticide treated fields, while no parasitoids were recovered from insecticide treated areas within the same region. The impact of feeding by Sunn Pest on different wheat stages indicated that only feeding prior to the spike stage does not affect the bread-making quality of the grain.     

Molecular mobility of fish flesh measured by low-field nuclear magnetic resonance (LF-NMR) relaxation: effects of freeze–thaw cycles

In this study, the molecular mobility of fish flesh was measured by low field nuclear magnetic resonance (LF-NMR) relaxation. Sardine, tuna and mackerel were frozen at ?40 °C and stored for 1 day (24 h); and then these samples were thawed at room temperature (20 °C). The relaxation of water protons in fish flesh was measured for fresh (i.e., before freezing) and multi-cycle freeze–thaw samples (i.e., up to 12 times). Three domains from different pools of protons (i.e., low-mobile, medium-mobile and high-mobile) were identified from the relaxation curve. The T _2b (low-mobile), T ₂₁ (medium-mobile) and T ₂₂ (high-mobile) indicated the proton populations in the protein molecules, strongly bound water molecules, and weakly bound water molecules, respectively. In all cases, the relaxation time (T _2b: sardine r = 0.736 and p < 0.01, tuna r = 0.857 and p < 0.001, mackerel r = 0.904 and p < 0.001; and T ₂₂: sardine r = 0.956 and p < 0.0001, tuna r = 0.927 and p < 0.0001, mackerel r = 0.890 and p < 0.0001) increased with the freeze–thaw cycles and it reached a nearly constant value after 6 freeze–thaw cycles. The increased relaxation time (i.e., higher mobility) up to 6 freeze–thaw cycles could be due to the increase in proton mobility. However, relaxation time (T ₂₁: sardine r = ?0.510 and p > 0.05, tuna r = 0.162 and p > 0.5, mackerel r = 0.513 and p > 0.01) showed insignificant change with the increase of freeze–thaw cycles, which indicated minimal change in the medium-mobile protons. The results in this study revealed that the changes in proton mobility in the fish flesh during freeze–thaw cycles could be identified using T _2b and T ₂₂ relaxation of LF-NMR.     

Removal of Atrazine Contamination in Soil and Liquid Systems Using Bioaugmentation

Reported levels of atrazine in soils at pesticide mix-load sites can vary between 7·9×10^-5 mM and 1·9 mM . We report on a mixed microbial culture, capable of degrading concentrations of atrazine in excess of 1·9 mM . At initial concentrations of 0·046 M and 0·23 M , the mixed population degraded 78% and 21% of atrazine in soil (100 days), respectively. At the same initial concentrations in liquid cultures, 90% and 56% of the atrazine was degraded (80 days), respectively. Decreased degradation in soil samples may have resulted from atrazine sorption to soil surfaces or decreased contact between the population and the herbicide. In the 0·23 M system, we attribute incomplete degradation to phosphorous depletion. Data for carbon dioxide evolution was fitted to a three-half-order regression model, but we feel that there are limitations of the application of this model to atrazine degradation. The population uses the herbicide as a nitrogen source and little carbon is incorporated into biomass, as the energy status of carbons in the ring leads to their direct evolution as [¹⁴C]carbon dioxide. This situation contributes to an evolution pattern that, when fitted to the three-half-order model, results in underestimation of the biomass produced. Data from our study suggest that our mixed culture could be used for bioremediation of atrazine at concentrations up to and exceeding those currently reported for agrochemical mixing-loading facilities. © 1997 SCI.     

Comparative study on immunomodulatory and growth enhancing effects of three prebiotics (galactooligosaccharide,fructooligosaccharide and inulin) in common carp (Cyprinus carpio)

This study investigated the effects of different prebiotics, including galactooligosaccharide (GOS), fructooligosaccharide (FOS) and inulin (INL), on skin mucosal immune parameters, humoral immune responses as well as performance of common carp (Cyprinus carpio). Two hundred and forty specimens (13.85 ± 0.85 g) were stocked in 12 fibreglass tanks assigned into three treatments and a control group. The experimental diets were formulated to have equal level (2%) of the prebiotics. At the end of the feeding trial, the highest skin mucus lysozyme activities and total immunoglobulin (total Ig) were observed in GOS‐fed group (P < 0.05). However, skin mucus protease activity showed no significant difference among different dietary groups (P < 0.05). Blood respiratory burst activity was significantly increased in all prebiotic‐fed fish compared to the control group (P < 0.05); the highest activity was observed in GOS treatment. Furthermore, evaluation of humoral immune response revealed that feeding with GOS‐supplemented diet significantly increased lysozyme and alternative complement (ACH50) activity as well as total Ig compared to the control and other prebiotic groups. While no significant difference was observed between FOS and INL groups, common carps fed GOS‐supplemented displayed improved (P < 0.05) growth performance, including final weight, weight gain, specific growth rate (SGR) and feed conversion ratio (FCR), compared to the control treatment. These results revealed that different prebiotics modulate carp growth and immune response in different manner, and GOS seems to be the most suitable prebiotic.