Tolerance or sensitivity responses of Mentha pulegium to osmotic and waterlogging stress in terms of antioxidant defense systems and membrane lipid peroxidation

This study investigated the changes in the antioxidants (Car, AsA), enzymatic antioxidant system (SOD, CAT, PODs), and lipid peroxidation levels of Mentha pulegium leaves with respect to incubation period under gradual osmotic and waterlogging stress conditions. Compared to the control levels, it was seen that, under both stress conditions, the relative leaf water, chlorophyll, and ascorbate contents were lower whereas carotenoid contents were higher. Osmotic stress generally activated all of the investigated antioxidant enzymes depending on the severity of stress. As implied by the strong positive correlation between the SOD and CAT under the high osmotic stress conditions, both activities increased by approximately a 2-fold on the 6th day. The activities of the SOD, CAT, and PODs enzymes were lower in comparison to the control levels under the waterlogged stress conditions. LPO levels increased a 2-fold for osmotic stress and a 4-fold for waterlogging stress on the 8th day. As extracted from data, it seems likely that both CAT and SOD work in a concerted way under osmotic stress as well as both studied peroxidases, which might probably act as first line against abiotic stress-induced ROS production. In addition, the profile described for CAT and SOD enzyme activities could be associated to a higher stress pressure. Consequently, the positive antioxidant response in M. pulegium might be responsible for higher tolerance to osmotic stress, whereas under waterlogging stress, the early accumulation of MDA seems to be associated to an impaired ability for radical scavenging. (C) 2011 Elsevier B.V. All rights reserved

Improving Wheat Performance by Fish Flour and Vermicompost Priming against Salt Stress

Fish flour (FF) and vermicompost (V) priming were used as exogenous growth enhancers to stimulate wheat (Triticum durum Desf. cv. Yelken) phenolic biosynthesis against high salt stress. The main aim was to address whether priming of wheat with fish flour and vermicompost-combined treatment could bring about supplementary benefits particularly against salt stress. Exogenous application of fish flour and vermicompost-combined treatment improved plant behavior in the presence of salt stress. However, the best results and synergy in terms of growth, seed vigor and total phenolic - flavonoids, chlorophyll - carotenoids contents, phenylalanine ammonia-lyase (PAL), peroxidase (POD) activities and lipid peroxidation content (LPO) were obtained in response to fish flour: vermicompost (1: 1)-combined treatment. (C) 2017 Friends Science Publisher

DOES FISH FLOUR AND CALCIUM IMPROVE MENTHA DEVELOPMENT, ENZYME ACTIVITIES AND PHENOLIC COMPOUNDS UNDER HIGH SALINITY

The use of natural and biodegradable material (such as fish flour) counteracts stress as cheaper and safer alternative for toxic chemicals (such as pesticides). The effect of calcium and fish flour (Ca and FF) (single or in combination) to improve plant tolerance against salt stress was studied. Sterilized mentha seeds were imbibed in each treatment: FF (10 g mL(-1)), Ca (1, 3%) applied alone and in Ca+FF-combination shaking for 24 h at 150 rpm. Changes in the antioxidants (carotenoids, phenolic, and flavonoid), enzymatic system (superoxidase - SOD, guaiacol-dependent peroxidase - GPX and phenylalanine ammonia-lyase - PAL) and lipid peroxidation levels of mentha seedlings were investigated under salt stress. It was suggested that Ca and/or FF had positive regulation effects on the key enzyme activities related to phenolic compounds biosynthesis and individual phenolic contents under salt stress. Additionally, the mentha plants developed from Ca+FF-combined pre-treatments showed better response to salinity than either Ca or FF single pretreatment. Suppression of salt injury by Ca+FF pre-treatment reduced the LPO levels, increased enzyme activities and promoted total flavonoid and phenolic contents. Ca+FF-combined pre-treatment of mentha seeds seem to be a reliable, not-expensive and easy procedure to enhance plant salt tolerance and to gain more biomass

Zinc-biofortified seeds improved seedling growth under zinc deficiency and drought stress in durum wheat

High zinc (Zn) concentration of seeds has beneficial effects both on seed vigor and human nutrition. This study investigated the effect of Zn biofortification on growth of young durum wheat (Triticum durum cv. Yelken) seedlings under varied Zn and water supply. The seeds differing in Zn concentrations were obtained by spraying ZnSO4 to durum wheat plants at different rates under field conditions. Three groups of seeds were obtained with the following Zn concentrations: 9, 20, and 50 mg Zn kg(-1). The seeds differing in Zn were tested for germination rate, seedling height, shoot dry matter production, and shoot Zn concentration under limited and well irrigated conditions in a Zn-deficient soil with and without Zn application. In an additional experiment carried out in solution culture, root and shoot growth and superoxide dismutase activity (SOD) of seedlings were studied under low and adequate Zn supply. Low seed Zn concentration resulted in significant decreases in seedling height both in Zn-deficient and sufficient soil, but more clearly under water-limited soil condition. Decrease in seed germination due to low seed Zn was also more evident under limited water supply. Increasing seed Zn concentration significantly restored impairments in seedling development. Drought-induced decrease in seedling growth at a given seed Zn concentration was much higher when soil was Zn-deficient. Increasing seed Zn concentration also significantly improved SOD activity in seedlings grown under low Zn supply, but not under adequate Zn supply. The results suggest that using Zn-biofortified seeds assures better seed vigor and seedling growth, particularly when Zn and water are limited in the growth medium. The role of a higher antioxidative potential (i.e., higher SOD activity) is discussed as a possible major factor in better germination and development of seedlings resulting from Zn-biofortified seeds

High seed zinc concentration assures high seedling vigor and biomass production in durum wheat under zinc deficiency and drought stress

Low seed Zn concentration resulted in decreased germination rate and seedling height, whereas increasing seed Zn concentration up to 50 mg kg-1 restored these traits under low soil Zn as well as drought or control treatments (Table 1). Germination rate was reduced to 66 % in seeds with 9 mg Zn kg-1 grown under low Zn and water availability whereas highest germination rates (i.e. up to 100 %) were recorded in seeds with 50 mg Zn kg-1 treated with adequate Zn and water (Table 1). Germination rate was gradually reduced by low seed Zn, particularly in the low soil Zn (i.e. 0 mg Zn kg-1 soil) and drought stress treatments (Table 1). In treatment with adequate soil Zn (i.e. 5 mg Zn kg-­‐1 soil) and water supply, seed Zn concentration had no effect on germination rate, however seedling height was significantly reduced by low Zn in the seed. Seedling height and also germination rate was reduced by drought as well as low Zn in the seed when plants were germinated and grown with adequate Zn in soil (Table 1). At the vegetative stage (i.e. stem elongation), high seed Zn concentration alleviated shoot biomass loss upon low Zn supply in soil irrespective of irrigation regimes (Table 2). Low Zn supply severely reduced shoot Zn concentration and increasing seed Zn concentration had little impact due to dilution of Zn in shoot. Increasing seed Zn concentration induced SOD activity (results not shown), dry matter production and Zn content (i.e. total Zn uptake per plant) of plants grown under low Zn supply (Table 2)

Zinc-biofortified seeds improved seedling growth under zinc deficiency and drought stress in durum wheat

High zinc (Zn) concentration of seeds has beneficial effects both on seed vigor and human nutrition. This study investigated the effect of Zn biofortification on growth of young durum wheat (Triticum durum cv. Yelken) seedlings under varied Zn and water supply. The seeds differing in Zn concentrations were obtained by spraying ZnSO4 to durum wheat plants at different rates under field conditions. Three groups of seeds were obtained with the following Zn concentrations: 9, 20, and 50 mg Zn kg(-1). The seeds differing in Zn were tested for germination rate, seedling height, shoot dry matter production, and shoot Zn concentration under limited and well irrigated conditions in a Zn-deficient soil with and without Zn application. In an additional experiment carried out in solution culture, root and shoot growth and superoxide dismutase activity (SOD) of seedlings were studied under low and adequate Zn supply. Low seed Zn concentration resulted in significant decreases in seedling height both in Zn-deficient and sufficient soil, but more clearly under water-limited soil condition. Decrease in seed germination due to low seed Zn was also more evident under limited water supply. Increasing seed Zn concentration significantly restored impairments in seedling development. Drought-induced decrease in seedling growth at a given seed Zn concentration was much higher when soil was Zn-deficient. Increasing seed Zn concentration also significantly improved SOD activity in seedlings grown under low Zn supply, but not under adequate Zn supply. The results suggest that using Zn-biofortified seeds assures better seed vigor and seedling growth, particularly when Zn and water are limited in the growth medium. The role of a higher antioxidative potential (i.e., higher SOD activity) is discussed as a possible major factor in better germination and development of seedlings resulting from Zn-biofortified seeds

Use of magnetic poly(glycidyl methacrylate) monosize beads for the purification of lysozyme in batch system

The hydrophobic affinity ligand L-tryptophan immobilized magnetic poly(glycidyl methacrylate) [m-poly(GMA)] beads in monosize form (1.6 mu m in diameter) were used for the affinity purification of lysozyme from chicken egg white. The m-poly(GMA) beads were prepared by dispersion polymerization in the presence of Fe3O4 nano-powder. The epoxy groups of the m-poly(GMA) beads were converted into amino groups with 1,6 diaminohexane (i.e., spacer arm). L-tryptophan was then covalently immobilized on spacer arm attached m-poly(GMA) beads. Elemental analysis of immobilised L-tryptophan for nitrogen was estimated as 42.5 mu mol/g polymer. Adsorption studies were performed under different conditions in a batch system (i.e., medium pH, protein concentration and temperature). Maximum lysozyme adsorption amount of m-poly(GMA) and m-poly(GMA)-L-tryptophan beads were 1.78 and 259.6 mg/g, respectively. The applicability of two kinetic models including pseudo-first order and pseudo-second order model was estimated on the basis of comparative analysis of the corresponding rate parameters, equilibrium adsorption capacity and correlation coefficients. Results suggest that chemisorption processes could be the rate-limiting step in the adsorption process. It was observed that after 10 adsorption-elution cycle, m-poly(GMA)-L-tryptophan beads can be used without significant loss in lysozyme adsorption capacity. Purification of lysozyme from egg white was also investigated. Purification of lysozyme was monitored by determining the lysozyme activity using Micrococcus lysodeikticus as substrate. It was found to be successful in achieving purification of lysozyme in a high yield of 76% with a purification fold of 71 in a single step. The specific activity of the eluted lysozyme (62,580 U/mg) was higher than that obtained with a commercially available pure lysozyme (Sigma (60,000 U/mg). (c) 2007 Elsevier B.V. All rights reserved

The Antioxidant Response System in Wheat Exposed to Pesticides and its Combined-induced Oxidative Damage

The aim of the present study was to analyze the alterations in the, antioxidant enzyme activities (such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and level of glutathione (GSH) and lipid peroxidation (LPO) of wheat acutely treated with CP and DM treatments at low, high doses and their combination. CP and DM were administered to wheat in different doses of 1, 1.5, 5 and 35 mg kg(-1) given alone and combination. After 3 weeks, antioxidant enzyme activities, and the level of GSH and LPO were recorded and analyzed. Antioxidative defense mechanisms and LPO in wheat display different responses depending on different pesticide treatments and doses. Biochemical analysis showed that exposure of the CP and DM cause plant tissue damage. It is suggested that appropriate ecotoxicological risk assessment should be made in the areas where DM is proposed to be used in pest control when compared to CP. In the present study, we also concluded that the effect of the combined of CP and DM on the oxidative stress may be synergistic

Oxidant/antioxidant status in premenstrual syndrome

To investigate oxidant/antioxidant status in premenstrual syndrome (PMS)