title: Assessment of the effect of silicon on antioxidant enzymes in cotton plants by multivariate analysis.
abstract: Silicon has been extensively researched in relation to the response of plants to biotic and abiotic stress, as an element triggering defense mechanisms which activate the antioxidant system. Furthermore, in some species, adding silicon to unstressed plants modifies the activity of certain antioxidant enzymes participating in detoxifying processes. Thus, in this study, we analyzed the activity of antioxidant enzymes in leaves and roots of unstressed cotton plants fertilized with silicon (Si). Cotton plants were grown in hydroponic culture and added with increasing doses of potassium silicate; then, the enzymatic activity of catalase (CAT), guaiacol peroxidase (GPOX), ascorbate peroxidase (APX), and lipid peroxidation were determined. Using multivariate analysis, we found that silicon altered the activity of GPOX, APX, and CAT in roots and leaves of unstressed cotton plants, whereas lipid peroxidation was not affected. The analysis of these four variables in concert showed a clear differentiation among Si treatments. We observed that enzymatic activities in leaves and roots changed as silicon concentration increased, to stabilize at 100 and 200 mg Si L(-1) treatments in leaves and roots, respectively. Those alterations would allow a new biochemical status that could be partially responsible for the beneficial effects of silicon. This study might contribute to adjust the silicon application doses for optimal fertilization, preventing potential toxic effects and unnecessary cost.
authors.affiliation: Facultad de Ciencias Exactas y Naturales, Universidad Nacional de La Pampa , Av. Uruguay 151, CP 6300 Santa Rosa, La Pampa, Argentina.
authors.forename: Carlos
authors.initials: C
authors.lastname: Alberto Moldes
authors.forename: Oscar
authors.initials: O
authors.lastname: Fontão de Lima Filho
authors.forename: José
authors.initials: J
authors.lastname: Manuel Camiña
authors.forename: Soraya
authors.initials: S
authors.lastname: Gabriela Kiriachek
authors.forename: María
authors.initials: M
authors.lastname: Lia Molas
authors.forename: Siu
authors.initials: S
authors.lastname: Mui Tsai
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D060387:Ascorbate Peroxidases / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D004798:Enzymes / Q000378:metabolism*; D003368:Gossypium / Q000187:drug effects* / Q000378:metabolism*; D018527:Hydroponics; D015227:Lipid Peroxidation / Q000187:drug effects; D015999:Multivariate Analysis; D009195:Peroxidase / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D012825:Silicon / Q000494:pharmacology*; D013312:Stress, Physiological
chemical_list: D000975:Antioxidants; D004798:Enzymes; C121048:guaiacol peroxidase; D060387:Ascorbate Peroxidases; D002374:Catalase; D009195:Peroxidase; D012825:Silicon