title: Contrasting effect of silicon on iron, zinc and manganese status and accumulation of metal-mobilizing compounds in micronutrient-deficient cucumber.
abstract: Although the beneficial role of silicon (Si) in alleviation of abiotic stress is well established, little is known of the relevance of Si nutrition under microelement deficiency. The aim of our work was to investigate the physiological role of Si in relation to micronutrient (Fe, Zn and Mn) deficiencies in cucumber (Cucumis sativus L.). Cucumber (cv. Semkross) plants were grown hydroponically in a complete nutrient solution (control) and in nutrient solutions free from Fe, Zn or Mn, with or without Si supply. Plant tissue concentrations of microelements, organic acids and phenolics were measured. Si supply effectively mitigated the symptoms of Fe deficiency, but only in part, the symptoms of Zn- or Mn deficiency. Leaf Fe concentration significantly increased in plants deprived of Fe but treated with Si, whereas the concentrations of other microelements were not affected by Si supply. The effects of Si supply in increasing accumulation of both organic acids and phenolic compounds in cucumber tissues were exclusively related to Fe nutrition. Enhancement of Fe distribution towards apical shoot parts, along with the tissue accumulation of Fe-mobilizing compounds such as citrate (in leaves and roots) or cathechin (in roots) appears to be the major alleviating effect of Si. Si nutrition, however, was without effect on the mobility and tissue distribution of either Zn or Mn.
authors: Department of Agricultural Chemistry, Saint Petersburg State University, 16th linia 29, V.O. Saint Petersburg 199178, Russia.
authors: Nikolai
authors: N
authors: Bityutskii
authors: Institute for Multidisciplinary Research (IMSI), University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia.
authors: Jelena
authors: J
authors: Pavlovic
authors: Department of Agricultural Chemistry, Saint Petersburg State University, 16th linia 29, V.O. Saint Petersburg 199178, Russia.
authors: Kirill
authors: K
authors: Yakkonen
authors: Institute for Multidisciplinary Research (IMSI), University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia.
authors: Vuk
authors: V
authors: Maksimović
authors: Institute for Multidisciplinary Research (IMSI), University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia. Electronic address: mnikolic@imsi.bg.ac.rs.
authors: Miroslav
authors: M
authors: Nikolic
mesh_terms: D018553:Cucumis sativus / Q000254:growth & development / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D008345:Manganese / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism; D018520:Plant Shoots / Q000378:metabolism; D012825:Silicon / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
chemical_list: D008345:Manganese; D007501:Iron; D015032:Zinc; D012825:Silicon
keywords: Cucumber; Micronutrient deficiency; Organic acids; Phenolics; Silicon