ascorbic-acid and paclobutrazol

Salinity extent and severity is rising because of poor management practices on agricultural lands, possibility lies to grow salt-tolerant crops with better management techniques. Therefore, a highly nutritive salt-tolerant crop quinoa with immense potential to contribute for future food security was selected for this investigation. Soil drenching of paclobutrazol (PBZ; 20 mg l

Topics: Antioxidants; Ascorbic Acid; Chenopodium quinoa; Gases; Ions; Lipid Peroxidation; Oxidation-Reduction; Photosynthesis; Plant Transpiration; Principal Component Analysis; Quantitative Trait, Heritable; Salinity; Sodium Chloride; Soil; Stress, Physiological; Triazoles

This investigation was carried out with the aim of determining the effect of paclobutrazol (PBZ) (0 and 2 mg l(-1)) and polyethylene glycol (PEG) (0, 2, 4 and 6 % w/v of PEG 6000) treatments on antioxidant system of Stevia rebaudiana Bertoni under in vitro condition. Analysis of data showed that PEG treatment significantly increased hydrogen peroxide (H2O2) and phenolic contents, while PBZ treatment limited the effect of PEG on them. Our data revealed that PEG treatment significantly increased total antioxidant capacity, catalase (CAT), ascorbate peroxidase (APX), polyphenol oxidase (PPO) and peroxidase (POD) activity, while it inversely decreased glutathione reductase (GR) activity. The superoxide dismutase (SOD) activity was not affected by PEG treatment. PBZ treatment induced significantly higher levels of CAT and GR activity and lower levels of SOD activity in PEG-treated plants. PBZ in combination with PEG resulted in no significant difference on APX activity with PEG treatment alone. PBZ treatment prevented the effect of PEG on the PPO activity. PEG (with or without PBZ) treatment increased the ascorbate pool, whereas total glutathione level was not affected by PEG. Our finding indicated that PBZ reduced the negative effect of PEG treatment by quenching H2O2 accumulation and increasing the CAT activity. Collectively, the antioxidant capacity of S. rebaudiana in PEG treatment condition was associated with active enzymatic and non-enzymatic defence systems which partly could be improved by the PBZ treatment. In addition, a higher accumulation of phenolic compounds leads to a more potent reactive oxygen species scavenging activity in S. rebaudiana.

Topics: Antioxidants; Ascorbic Acid; Culture Techniques; Glutathione; Hydrogen Peroxide; Phenols; Polyethylene Glycols; Stevia; Triazoles

This investigation was carried out at Mahasarakham University Experimental Farm, Mahasarakham University, Northeast Thailand in the late rainy season of the 2003 to 2004 with the use of Roi-Et soil series (Oxic Paleustults). The experiment aims to search for more information on the effect of different rates of chemical Paclobutrazol (PBZ) application on growth, yield and quality of edible okra pods. A Randomised Complete Block Design (RCDB) with four replications was used for the experiment. The experiments consisted of five treatments, i.e., 0 (T1), 4000 (T2), 8000 (T3), 12,000 (T4) and 16,000 ppm ha(-1) (T5) of chemical PBZ. The results showed that an increase in PBZ application rate highly decreased plant height, harvesting age and significantly decreased leaf area of the fifth leaf but highly increased pod length, fresh weight/pod and fresh pod yield ha(-1) of the okra plants. PBZ had no significant effect on stem diameter and diameter of pods of the okra plants. Total soluble solid, fibre content, titratable acid, vitamin C and pectin contents in pods were not affected by chemical PBZ application. Pod yield highly increased with an increase in rate of PBZ application. The highest edible pod yield reached a value of 4501 kg ha(-1) for the highest rate of PBZ application (T5).

Topics: Abelmoschus; Acids; Agriculture; Ascorbic Acid; Pectins; Plant Leaves; Plant Stems; Solubility; Thailand; Titrimetry; Triazoles

An investigation was carried out to find out the extent of changes occurred in groundnut (Arachis hypogaea L.) cultivars in response to paclobutrazol (PBZ) treatment under water deficit stress. Two groundnut cultivars namely ICG 221 and ICG 476 were used for the study. Individual treatment with PBZ and drought stress showed an increase in ascorbic acid, alpha-tocopherol and reduced glutathione, superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT) activities. PBZ with drought stressed plants maintained higher levels of antioxidant and scavenging enzymes. Significant differences were observed between cultivars and treatments. These results suggests that the adverse effects of water stress can be minimized by the application of PBZ by increasing the antioxidant levels and activities of scavenging enzymes such as SOD, APX and CAT. The Cv. ICG 221 appears to be more tolerant to water stress than the ICG 476.

Topics: alpha-Tocopherol; Antioxidants; Arachis; Ascorbate Peroxidases; Ascorbic Acid; Catalase; Enzyme Activation; Free Radical Scavengers; Fungicides, Industrial; Glutathione; Peroxidases; Superoxide Dismutase; Triazoles; Water

The effect of paclobutrazol (PBZ) treatments on the antioxidant metabolism of white yam (Dioscorea rotundata Poir.) was investigated in the present study. PBZ @ 15 mg l(-1) plant(-1) was given to plants by soil drenching, 30, 60, and 90 days after planting (DAP). The non-enzymatic antioxidant contents like ascorbic acid (AA), reduced glutathione (GSH) and alpha-tocopherol (alpha-toc), activities of antioxidant enzymes like superoxide dismutase (SOD), ascorbate peroxidase (APX), polyphenol oxidase (PPO) and catalase (CAT) were extracted and assayed on 100 DAP from leaf, stem and tubers of both control and PBZ treated plants. It was found that PBZ has a profound effect on the antioxidant metabolism and caused an enhancement in both non-enzymatic and enzymatic antioxidant potentials under treatments in white yam. Our results have good significance, as this increase the innate antioxidant potential of this food crop, which is helpful to satisfy the needs of antioxidants in diet and thereby make it an economically important food crop.

Topics: alpha-Tocopherol; Antioxidants; Ascorbate Peroxidases; Ascorbic Acid; Catalase; Catechol Oxidase; Dioscorea; Glutathione; Peroxidases; Plant Leaves; Plant Roots; Plant Stems; Superoxide Dismutase; Triazoles