title: Effects of phosphorus fertilizer supplementation on antioxidant enzyme activities in tomato fruits.
abstract: The effects of soil and foliar phosphorus supplementation on the activities and levels of superoxide dismutase (SOD), guaiacol peroxidase (POX), and ascorbate peroxidase (APX) in tomato fruits were evaluated by determining enzyme activities and isoenzyme analysis. Both protein levels and enzyme activities varied depending on the variety and season. In general, phosphorus supplementation did not alter SOD, POX, and APX activities significantly;however, some treatments showed season- and stage-specific enhancement in activities as noticed with hydrophos and seniphos supplementation. Three different SOD isozymes were observed, and these isozymes showed very similar staining intensities in response to P application and during the three developmental stages studied. Two major isozymes of POX and two different APX isozymes were observed at all the developmental stages. The results suggest that antioxidant enzyme activities may be influenced by the availability of phosphorus, but are subject to considerable variation depending on the developmental stage and the season.
authors.affiliation: Department of Plant Agriculture, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
authors.forename: Taehyun
authors.initials: T
authors.lastname: Ahn
authors.forename: Moustapha
authors.initials: M
authors.lastname: Oke
authors.forename: Andrew
authors.initials: A
authors.lastname: Schofield
authors.forename: Gopinadhan
authors.initials: G
authors.lastname: Paliyath
mesh_terms: D000975:Antioxidants; D060387:Ascorbate Peroxidases; D005308:Fertilizers; D005638:Fruit / Q000201:enzymology*; D007527:Isoenzymes / Q000378:metabolism; D018551:Solanum lycopersicum / Q000201:enzymology*; D009195:Peroxidase / Q000378:metabolism; D010544:Peroxidases / Q000378:metabolism; D010758:Phosphorus / Q000008:administration & dosage*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D005308:Fertilizers; D007527:Isoenzymes; D010758:Phosphorus; D010544:Peroxidases; C121048:guaiacol peroxidase; D060387:Ascorbate Peroxidases; D009195:Peroxidase; D013482:Superoxide Dismutase