{"type": "FeatureCollection", "features": [{"id": "10.1016/j.jplph.2012.02.014", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:16:31Z", "type": "Journal Article", "created": "2012-04-24", "title": "Drought Stress Has Contrasting Effects On Antioxidant Enzymes Activity And Phenylpropanoid Biosynthesis In Fraxinus Ornus Leaves: An Excess Light Stress Affair?", "description": "The experiment was conducted using Fraxinus ornus plants grown outside under full sunlight irradiance, and supplied with 100% (well-watered, WW), 40% (mild drought, MD), or 20% (severe drought, SD) of the daily evapotranspiration demand, with the main objective of exploring the effect of excess light stress on the activity of antioxidant enzymes and phenylpropanoid biosynthesis. Net CO\u2082 assimilation rate at saturating light and daily assimilated CO\u2082 were significantly smaller in SD than in WW and MD plants. Xanthophyll-cycle pigments supported nonphotochemical quenching to a significantly greater extent in SD than in MD and WW leaves. As a consequence, the actual efficiency of PSII (\u03a6(PSII)) was smaller, while the excess excitation-energy in the photosynthetic apparatus was greater in SD than in WW or MD plants. The concentrations of violaxanthin-cycle pigments relative to total chlorophyll (Chl(tot)) exceeded 200 mmol mol\u207b\u00b9 Chl(tot) in SD leaves at the end of the experiment. This leads to hypothesize for zeaxanthin a role not only as nonphotochemical quencher, but also as chloroplast antioxidant. Reductions in ascorbate peroxidase and catalase activities, as drought-stress progressed, were paralleled by greater accumulations of esculetin and quercetin 3-O-glycosides, both phenylpropanoids having effective capacity to scavenge H\u2082O\u2082. The drought-induced accumulation of esculetin and quercetin 3-O-glycosides in the vacuoles of mesophyll cells is consistent with their putative functions as reducing agents for H\u2082O\u2082 in excess light-stressed leaves. Nonetheless, the concentration of H\u2082O\u2082 and the lipid peroxidation were significantly greater in SD than in MD and WW leaves. It is speculated that vacuolar phenylpropanoids may constitute a secondary antioxidant system, even on a temporal basis, activated upon the depletion of primary antioxidant defences, and aimed at keeping whole-cell H\u2082O\u2082 within a sub-lethal concentration range.", "keywords": ["0301 basic medicine", "Analysis of Variance", "Principal Component Analysis", "0303 health sciences", "Time Factors", "Light", "Propanols", "Antioxidant enzymes Drought stress Phenylpropanoids Water relations Violaxanthin-cycle pigments", "Hydrogen Peroxide", "Pigments", " Biological", "Carbon Dioxide", "15. Life on land", "Antioxidants", "6. Clean water", "Antioxidant enzymes; Drought stress; Phenylpropanoids; Violaxanthin-cycle pigments; Water relations; Analysis of Variance; Antioxidants; Carbon Dioxide; Fraxinus; Hydrogen Peroxide; Malondialdehyde; Mesophyll Cells; Microscopy", " Fluorescence; Photosynthesis; Pigments", " Biological; Plant Leaves; Principal Component Analysis; Propanols; Stress", " Physiological; Time Factors; Droughts; Light; Plant Science; Physiology; Agronomy and Crop Science", "Droughts", "Plant Leaves", "03 medical and health sciences", "Fraxinus", "Microscopy", " Fluorescence", "Stress", " Physiological", "Antioxidant enzymes; drought stress; flavonoids", "Malondialdehyde", "Photosynthesis", "Mesophyll Cells"]}, "links": [{"href": "https://doi.org/10.1016/j.jplph.2012.02.014"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Journal%20of%20Plant%20Physiology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.jplph.2012.02.014", "name": "item", "description": "10.1016/j.jplph.2012.02.014", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.jplph.2012.02.014"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2012-07-01T00:00:00Z"}}, {"id": "10.17221/113/2010-pse", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:19:47Z", "type": "Journal Article", "created": "2018-02-10", "title": "Selenium Biofortification And Antioxidant Activity In Lettuce Plants Fed With Selenate And Selenite", "description": "Selenium is an important element associated with enhancement of antioxidant activity in plants, microorganisms, animals, and humans. In Brazil, the information on Se in agricultural crops is lacking, though there are indications that low levels of Se are consumed by the population. The experiment was conducted under greenhouse conditions with pots containing 3 l of nutritive solution in a completely randomized factorial design, with seven Se concentrations (0, 2, 4, 8, 16, 32, and 64 \u00b5mol/l) and two forms of Se (sodium selenate - Na2SeO4 and sodium selenite - Na2SeO3), with six replicates. The application of Se as selenate at low concentrations is more appropriate for lettuce biofortification because it favors shoot biomass growth and Se levels in the shoot biomass. Selenium in both forms had two effects on lettuce plant metabolism: at low doses it acted as an antioxidant and enhanced plant growth, whereas at higher levels it reduced yield.", "keywords": ["0106 biological sciences", "2. Zero hunger", "selenate", "Plant culture", "04 agricultural and veterinary sciences", "01 natural sciences", "Selenate", "SB1-1110", "3. Good health", "biofortification", "antioxidant enzymes", "Selenite", "0401 agriculture", " forestry", " and fisheries", "Antioxidant enzymes", "selenite", "Biofortification"]}, "links": [{"href": "https://doi.org/10.17221/113/2010-pse"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Plant%2C%20Soil%20and%20Environment", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.17221/113/2010-pse", "name": "item", "description": "10.17221/113/2010-pse", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.17221/113/2010-pse"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2010-12-31T00:00:00Z"}}, {"id": "10.17221/559/2012-pse", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:19:47Z", "type": "Journal Article", "created": "2018-02-10", "title": "Response Of Brachiaria Grass To Selenium Forms Applied In A Tropical Soil", "description": "In Brazil the total area of native and cultivated pasture used for livestock is around 180 million hectares, and selenium (Se) is absent from mineral fertilizer formulas. Nutritional supplementation of this element takes place along with provision of mineral salts in the form of sodium selenite. In the present work, the effects of adding selenate and selenite on Se biofortification, antioxidant activity and anatomy alterations in Brachiaria brizantha were evaluated. The experiments were disposed in a completely randomized design in a 6 \u00d7 2 factorial scheme, by means of five levels of Se (0; 0.5; 1.0; 3.0 and 6.0 mg/kg) applied along with grass plant fertilizer, and two Se forms (sodium selenate and sodium selenite), with six replications. The results of the present study suggest that, in tropical soil conditions, the application of Se as selenate at low doses is more appropriate for B. brizantha biofortification than Se as selenite, because it favors a greater shoot Se levels, better activation of the antioxidant system and reduces on lipid peroxidation. Finally, with an increase of Se rates, cellular modifications were observed in internal structures of roots in B. brizantha, with aerenchyma appearing.", "keywords": ["0106 biological sciences", "2. Zero hunger", "Forage", "Brachiaria brizantha", "Root anatomy", "forage", "Plant culture", "04 agricultural and veterinary sciences", "15. Life on land", "01 natural sciences", "SB1-1110", "biofortification", "root anatomy", "antioxidant enzymes", "0401 agriculture", " forestry", " and fisheries", "Antioxidant enzymes", "brachiaria brizantha", "Biofortification"], "contacts": [{"organization": "Ramos, S\u00edlvio Junio, \u00c1vila, Fabricio William de, Boldrin, Paulo Fernandes, Pereira, Fabr\u00edcio Jos\u00e9, Castro, Evaristo Mauro de, Faquin, Valdemar, Reis, Andr\u00e9 Rodrigues dos, Guilherme, Luiz Roberto Guimar\u00e3es,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.17221/559/2012-pse"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Plant%2C%20Soil%20and%20Environment", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.17221/559/2012-pse", "name": "item", "description": "10.17221/559/2012-pse", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.17221/559/2012-pse"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2012-11-30T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Antioxidant+enzymes&f=json", "hreflang": "en-US"}, {"rel": "alternate", "type": "text/html", "title": "This document as HTML", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Antioxidant+enzymes&f=html", "hreflang": "en-US"}, {"rel": "collection", "type": "application/json", "title": "Collection URL", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main", "hreflang": "en-US"}, {"type": "application/geo+json", "rel": "first", "title": "items (first)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Antioxidant+enzymes&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Antioxidant+enzymes&offset=3", "hreflang": "en-US"}], "numberMatched": 3, "numberReturned": 3, "distributedFeatures": [], "timeStamp": "2026-05-26T03:53:34.023160Z"}