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Drought stress poses a significant obstacle to agricultural productivity, particularly in the case of oilseed crops such as sunflower (Helianthus annuus L.). Selenium (Se) is a fundamental micronutrient that has been recognized for its ability to enhance plant resilience in the face of various environmental stresses. The FH-770 sunflower variety was cultivated in pots subjected to three stress levels (100% FC, 75% FC, and 50% FC) and four Se application rates (0 ppm, 30 ppm, 60 ppm, and 90 ppm). This research aimed to investigate the effect of exogenously applied Se on morpho-physiological and biochemical attributes of sunflower to improve the drought tolerance. Foliar Se application significantly lowered H2O2 (hydrogen peroxide; ROS) (20.89%) accumulation that markedly improved glycine betaine (GB) (74.46%) and total soluble protein (Pro) (68.63%), improved the accumulation of ascorbic acid (AA) (25.51%), total phenolics (TP) (39.34%), flavonoids (Flv) (73.16%), and anthocyanin (Ant) (83.73%), and improved the activity of antioxidant system superoxide dismutase (SOD) (157.63%), peroxidase (POD) (100.20%), and catalase (CAT) (49.87%), which ultimately improved sunflower growth by 36.65% during drought stress. Supplemental Se significantly increased shoot Se content (93.86%) and improved calcium (Ca2+), potassium (K+), and sodium (Na+) ions in roots by 36.16%, 42.68%, and 63.40%, respectively. Seleniumsupplements at lower concentrations (60 and 90 ppm) promoted the growth, development, and biochemical attributes of sunflowers in controlled and water-deficient circumstances. However, selenium treatment improved photosynthetic efficiency, plant growth, enzymatic activities, osmoregulation, biochemical characteristics, and nutrient balance. The mechanisms and molecular processes through which Se induces these modifications need further investigation to be properly identified. [ABSTRACT FROM AUTHOR]

Exogenous application of antioxidants can be helpful for plants to resist salinity, which can be a potentially simple, economical, and culturally feasible approach, compared with introgression and genetic engineering. Foliar spraying of alpha-tocopherol (α-tocopherol) is an approach to improve plant growth under salinity stress. Alpha-tocopherol acts as an antioxidant preventing salinity-induced cellular oxidation. This study was designed to investigate the negative effects of salinity (0 and 120mM NaCl) on linseed (Linum usitatissimum L.) and their alleviation by foliar spraying of α-tocopherol (0, 100, and 200mg L−1). Seeds of varieties "Chandni and Roshni" were grown in sand-filled plastic pots, laid in a completely randomized design in a factorial arrangement, and each treatment was replicated three times. Salinity significantly affected linseed morphology and yield by reducing shoot and root dry weights, photosynthetic pigment (Chl. a , Chl. b , total Chl., and carotenoids) contents, mineral ion (Ca2+, K+) uptake, and 100-seed weight. Concomitantly, salinity increased Na+, proline, soluble protein, peroxidase, catalase, and superoxide dismutase activities in both varieties. Conversely, the growth and yield of linseed varieties were significantly restored by foliar spraying of α-tocopherol under saline conditions, improving shoot and root dry matter accumulation, photosynthetic pigment, mineral ion, proline, soluble protein contents, peroxidase, catalase, superoxide dismutase activities, and 100-seed weight. Moreover, foliar spray of α-tocopherol alleviated the effects of salinity stress by reducing the Na+ concentration and enhancing K+ and Ca2+ uptake. The Chandni variety performed better than the Roshni, for all growth and physiological parameters studied. Foliar spray of α-tocopherol (200mg L−1) alleviated salinity effects by improving the antioxidant potential of linseed varieties, which ultimately restored growth and yield. Therefore, the use of α-tocopherol may enhance the productivity of linseed and other crops under saline soils. [ABSTRACT FROM AUTHOR]

In this experiment, effect of lead (Pb) + chromium (Cr) mixture on superoxide dismutase (SOD) in the liver of Labeo rohita at a concentration of 11.1 mgL-1 was observed. The ammonium sulphate precipitation and ion exchange chromatography techniques were successfully used to purify SOD. After purification, SOD activity of control and Pb+Cr treated fish was noted as 581.00 and 645.45 UmL-1, respectively while the specific activity was 1383.33 and 1613.62 Umg-1, respectively. The fold purification value of SOD was 2.75 and 2.45 for control and stressed fish, respectively. The recovery was calculated as 77.06 and 57.43% for control and stressed fish, respectively. The results of kinetic characterization showed that SOD form control and exposed fish had maximum activity at pH 6.5 and 7.0. Temperature also had a significant effect on activity of SOD. The SOD activity was measured maximum at 30°C for both control and Pb+Cr exposed fish. The Km value of liver SOD for control and Pb+Cr treated L. rohita was calculated as 1.48 and 0.62 mM, respectively. The value of Vmax for SOD from liver of control and Pb+Cr exposed fish was 1000 and 570 U mL-1, respectively. The enthalpy of denaturation (ΔH*) for liver SOD from control and Pb+Cr exposed L. rohita was computed as 3.492 and 2.802 KJ mol-1 at 40°C, respectively and these values were dropped off with increasing the temperature until it remains 3.251 and 2.561 KJ mol-1 at 70°C, respectively. The free energy of thermal denaturation (ΔG°) of liver SOD was slightly increased with increasing temperature until 75°C which shows its resistance against heat. The values of ΔG° was observed as 58.03 and 57.95 KJ mol-1 for control and exposed fish at 40°C, respectively while the same was increased upto 62.37 and 62.00 KJ mol-1 at 70°C, respectively. It was concluded from negative value of ΔS* (entropy of inactivation) that the SOD is stable thermodynamically. [ABSTRACT FROM AUTHOR]

The aim of the present study was to determine the level of selected toxicants in water, their bioaccumulation and effects on antioxidant enzymes i.e. superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in vital organs (gills, liver and kidney) of fish, Cirrhina mrigala. The 3 different representative water samples and 60 fish samples (20 fish from each site) were collected from three sites i.e. fishfarm, hatchery and Indus River of Punjab, Pakistan. The results showed differences in physico-chemical parameters of water samples collected from all the sites. The concentrations of Zinc (Zn), copper (Cu) and nickel (Ni) were higher in river water as compared to farm and hatchery. Different organs of fish collected from different sites showed variations in their metal concentration. In Indus River fish, the concentrations of metals were highest in liver followed by kidney and gills. The Indus River fish also exhibited highest SOD activity in all the organs as compared to farm and hatchery fish. The activity of CAT enzyme was higher in kidneys and gills of farm fish compared to the liver of hatchery fish. The maximum POD activity was recorded in liver, kidney and gills of hatchery fish. This study reveals that fish could acquire higher uptake of metals due to excessive pollution of heavy metals and other toxic elements in river water. In response to metals toxicity, the antioxidant system can be useful as an early warning tool in natural monitoring studies. [ABSTRACT FROM AUTHOR]

The current study was conducted to determine the tolerance limits of Indian major carps viz. Catla catla, Cirrhina mrigala and Labeo rohita against pesticides mixture (Bifenthrin + Chlorpyrifos + Endosulfan) and to see it effect on antioxidant enzyme like superoxide dismutase (SOD) activity in the liver of these species. The 96-hr LC50 and lethal concentration of pesticides mixture (BIF+CPF+END) for C. catla, C. mrigala and L. rohita was determined in the static bioassay methods as 1.09, 1.81 1.63 and 1.90, 2.78, 2.30 µgL-1, respectively.C. catla exhibited higher sensitivity toward tertiary pesticides mixture followed by L. rohita and C. mrigala. The activity of SOD in the liver of all three fish species exposed to pesticides mixture was significantly (p<0.05) higher as compare to control fish. The SOD activity showed time dependent increasing trend in the liver of all three fish species. [ABSTRACT FROM AUTHOR]

Concerns regarding zinc oxide nanoparticles (ZnO-NPs) have gained much attention due to their unique properties and widespread applications in cosmetics, electronics and medicinal industry that may induce an adverse impact not only on specific ecosystem but also on human health. ZnO-NPs were synthesized by coprecipitation method and characterization was done by Scanning electron microscope (SEM), X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) analysis. SEM showed the hexagonal wurtzite crystal structure of particles. From XRD pattern, average particle size, lattice parameters (a and c), X-ray density and volume of unit cell of zinc oxide nanoparticles were 52.22 nm, (a =3.25 Å and c=5.21 Å), 5.0 g/cm3 and 54.82 ų, respectively. FT-IR confirmed the attached compound of synthesized nanoparticles. The acute toxicity of ZnO-NPs was determined by using fish, Labeo rohita as a genetic model during this study. The mean 96-h LC50 and lethal concentration were measured as 31.15 and 57.84 mg/L, respectively. Oxidative stress in terms of catalase, lipid peroxidation and superoxide dismutase was also determined in fish gills, muscle, liver and heart after chronic exposure of ZnO-NPs for 80 days and sampling were done on 20, 40, 60 and 80 days. Significantly decreased catalase and superoxide dismutase activity was determined in selected fish organs. However, level of lipid peroxidation was significantly increased in the fish organs as compared to control group. The overall results indicated that induced toxicity mechanism of ZnO-NPs in aquatic ecosystem was oxidative stress. [ABSTRACT FROM AUTHOR]