Nitrogen Form Alters Hormonal Balance in Salt-treated Tomato (Solanum lycopersicum L.) |
| |
Authors: | Michel Edmond Ghanem Cristina Mart��nez-And��jar Alfonso Albacete Hana Posp��?ilov�� Ian C. Dodd Francisco P��rez-Alfocea Stanley Lutts |
| |
Affiliation: | (1) Groupe de Recherche en Physiologie v?g?tale, Earth and Life Institute, Universit? catholique de Louvain, 5 (Bte 13) Place Croix du Sud, 1348 Louvain-la-Neuve, Belgium;(2) Departamento de Nutrici?n Vegetal, Centro de Edafolog?a y Biolog?a Aplicada del Segura (CEBAS), Consejo Superior de Investigaciones Cient?ficas (CSIC), Campus Universitario de Espinardo, 30100 Espinardo, Murcia, Spain;(3) Department of Biochemistry, Palack? University, 779 00 Olomouc, Czech Republic;(4) The Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK;(5) Present address: Department of Horticulture-Seed Biology, Oregon State University, Corvallis, OR 97331, USA;(6) Present address: Plant Physiology Group, Institute of Plant Sciences, Karl-Franzens University of Graz, Schubertstra?e 51, 8010 Graz, Austria; |
| |
Abstract: | Mixed nitrate/ammonium fertilization can partially alleviate the negative effects of salinity on growth of some plant species compared to all-nitrate or all-ammonium fertilization. To gain insights about the mechanisms involved, tomato (Solanum lycopersicum L. cv Moneymaker) plants were grown hydroponically for 3 weeks with two NO3 −/NH4 + fertilization regimes (6/0.5 and 5/1.5; Ntotal = 6.5 mM) in the absence (control) or presence of salt stress (100 mM NaCl). Ammonium enrichment had no effect on growth and other parameters under control conditions. Under salinity, however, ammonium enrichment improved shoot and root biomass by 20% and maintained leaf PSII efficiency close to control levels. These changes were related to higher leaf K+, NO3 −, and NH4 + concentrations and activities of the N-assimilatory enzymes glutamate synthase (GOGAT) and glutamine synthase (GS) in the leaves. Ammonium enrichment also attenuated the salt-induced increase in leaf abscisic acid (ABA) concentration and decrease in leaf concentrations of indole 3-acetic acid (IAA) and the cytokinins trans-zeatin (tZ) and trans-zeatin riboside (tZR). Enhanced cytokinin status was probably due to maintenance of root-to-shoot cytokinin transport and decreased leaf induction of the cytokinin-degrading enzyme cytokinin oxidase/dehydrogenase (CKX) under ammonium-enriched conditions. It is concluded that nitrogen form modifies salinity-induced physiological responses and that these modifications are associated with changes in plant hormone status. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|