Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Nitrogen Form Alters Hormonal Balance in Salt-treated Tomato (Solanum lycopersicum L.)
AU - Ghanem, Michel Edmond
AU - Martinez-Andujar, Cristina
AU - Albacete, Alfonso
AU - Pospisilova, Hana
AU - Dodd, Ian C.
AU - Perez-Alfocea, Francisco
AU - Lutts, Stanley
PY - 2011/6
Y1 - 2011/6
N2 - 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; N-total = 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.
AB - 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; N-total = 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.
KW - Abscisic acid
KW - Ammonium
KW - Cytokinin
KW - Indole-3-acetic acid
KW - Nitrate
KW - Nitrogen metabolism
KW - Plant hormones
KW - Salt stress
KW - Sodium chloride
KW - Tomato (Solanum lycopersicum L.)
KW - trans-Zeatin
KW - trans-Zeatin riboside
KW - PHOSPHOENOLPYRUVATE CARBOXYLASE ACTIVITY
KW - GLUTAMATE-DEHYDROGENASE
KW - NITRATE REDUCTASE
KW - LEAF SENESCENCE
KW - GENE-EXPRESSION
KW - WATER-DEFICIT
KW - ABSCISIC-ACID
KW - XYLEM SAP
KW - SALINITY
KW - PLANTS
U2 - 10.1007/s00344-010-9178-4
DO - 10.1007/s00344-010-9178-4
M3 - Journal article
VL - 30
SP - 144
EP - 157
JO - Journal of Plant Growth Regulation
JF - Journal of Plant Growth Regulation
SN - 0721-7595
IS - 2
ER -