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Low-temperature storage is generally used to extend postharvest lifetime and to inhibit decay of cucumber fruit, but it also enhances the intensity of chilling injury. The capability of γ-aminobutyric acid to enhance antioxidant enzyme activities and reduce chilling injury was studied in cucumber ( L.) fruit stored at 1 °C for 5 weeks. The purpose of this study was to define if the GABA-induced modification in antioxidant system and phospholipase activity is linked to the reduced chilling injury in cold-stored cucumber fruit. Alleviation of chilling injury by GABA treatment was related to increased content of proline, endogenous GABA and enhanced activities of CAT and SOD, together with reduced activities of PLC, PLD and LOX. We suggest that PLC, LOX and PLD are associated with chilling injury initiation by involvement in a signaling pathway and membrane deterioration. Therefore the results obtained in this study suggest GABA's potential for postharvest applications for reducing chilling injury symptom in cucumber fruit.

Salinity (NaCl Stress) was applied with 50, 100, 200, 300 and 400 mM NaCl. The shoot and root respiration of two barley cultivars (Hordeum vulgare L. variety Afzal and variety EMB82-12) were determined in various concentrations ofNaCl. Chlorophyll a, b and total chlorophyll content were significantly decreased, but carotenoids content increased under salinity. Decrease of chlorophyll content in EMB82-12 was higher than Afzal, but carotenoids content in Afzal variety was higher than EMB82-12. Relative Water Content (RWC) was used to indicate the degree of stress. Oxygen uptake declined in shoot and root with increasing NaCl concentrations. Decrease of oxygen uptake in shoot and root of EMB82-12 variety was higher than Afzal variety. RWC decreased with increasing NaCl concentrations. Lowering of RWC reduced growth and increased shoot/root ratio. Decrease of water content in EMB82-12 plants was higher than Afzal plants. Shoot/root ratio in EMB82-12 variety was higher than Afzal.

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Salinity (NaCl stress) was applied with 50, 100, 200, 300 and 400 mM NaCl. The shoot and root water content and organic solutes contents of two barley varieties (Hordeum vulgare L. var. Afzal and var. EMB82-12) were determined in various concentrations of NaCl. Soluble sugar and proline contents were increased in two barley varieties in response to increased salt concentration, but this increase in Afzal var. were higher than EMB82-12. Soluble protein content was decreased in two barley varieties in response to different salt regimes and this decrease in Afzal var. was lower than EMB82-12 var. RWC decreased with increasing NaCl concentrations. Decrease of water content in EMB82-12 plants was higher than Afzal plants.

The highly sensitive impedimetric biosensor in label free approach for hepatitis B virus DNA (HPV DNA) detection based on tellurium doped ZnO nanowires was fabricated. The NWs were grown by hybrid thin film oxidation in the physical vapor deposition (PVD) mechanism. The morphology characterization of the synthesized NWs was performed by field emission scanning electron microscopy (FESEM) and the images demonstrated that the diameter and the length of the materialized NWs were around 50 nm and several micrometers, respectively. The high-resolution transmission electron microscopy (HRTEM) image indicated that the fabricated NWs were crystalline and their phase characterization was validated by the X-ray diffraction pattern (XRD pattern). The single-stranded DNA (ss DNA) probe was immobilized on the surface of the Te-ZnO NWs. The electrochemical impedance spectra (EIS) measurements showed high response sensitivity after hybridization with complementary oligonucleotides. The biosensor could distinguish complementary target from non-complementary and mismatch oligonucleotides. The HBV biosensor could respond to complementary target in the concentrations range from 1 pM to 1 μM. The limit of detection (LOD) of the biosensor was 0.1 pM. The stability of the HBV DNA biosensor was investigated and biosensor could show 95% of its initial responses after 8 weeks maintenance.

In this study, we investigated antioxidant responses of activities of Superoxide Dismutase (SOD), Catalase (CAT), Ascorbate Peroxidase (APX) and Guaiacol Peroxidase (GPX) to saline stress in two barley varieties named Hordeum vulgare L. var. Afzal and var. EMB82-12 treated with 50, 100, 200, 300 and 400 mM NaCl for 3 days. The MDA content of Afzal plants grown under different salt regimes remained nearly constant but it largely increased in EMB82-12 plants under the same conditions. There was a linear and significant correlation in CAT, APX, SOD, GPX activities in Afzal plants in response to increased salt concentration. The strong and positive correlation between antioxidant enzymes and salt concentrations, may account for the MDA level of Afzal plants remaining constant in response to different salt regimes. In general, the activities of antioxidant enzymes were increased in the root and shoot under saline stress. But the increase was more significant and consistent in the root. Among the antioxidant enzymes, CAT activity was increased the most drastically.

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