Details

Autor(en) / Beteiligte

• Monteiro, Carolina C.
• Carvalho, Rogério F.
• Gratão, Priscila L.
• Carvalho, Giselle
• Tezotto, Tiago
• Medici, Leonardo O.
• Peres, Lázaro E.P.
• Azevedo, Ricardo A.

Titel

Biochemical responses of the ethylene-insensitive Never ripe tomato mutant subjected to cadmium and sodium stresses

Ist Teil von

• Environmental and experimental botany, 2011-06, Vol.71 (2), p.306-320

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2011

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• ▶ We used the ethylene-insensitive Never ripe (Nr) tomato (Solanum lycopersicum L.) mutant and Micro-Tom, which blocks ethylene responses, to investigate the oxidative stress responses to Cd and NaCl. ▶ Similar growth patterns and Na and Cd accumulation for MT and Nr were observed but the mutant exhibited reduced leaf chlorophyll degradation following stress. ▶ One specific superoxide isoenzyme from roots responded differently to NaCl and CdCl2 exposure, but was not genotype specific. ▶ Overall the results indicate that the ethylene signaling associated with NR receptor can modulate the biochemical pathways of oxidative stress in a tissue dependent manner, and that this signaling may be different following Na and Cd exposure. In order to further address the known interaction between ethylene and components of the oxidative system, we have used the ethylene-insensitive Never ripe (Nr) tomato (Solanum lycopersicum L.) mutant, which blocks ethylene responses. The mutant was compared to the control Micro-Tom (MT) cultivar subjected to two stressful situations: 100mM NaCl and 0.5mM CdCl2. Leaf chlorophyll, lipid peroxidation and antioxidant enzyme activities in roots, leaves and fruits, and Na and Cd accumulation in tissues were determined. Although we verified a similar growth pattern and Na and Cd accumulation for MT and Nr, the mutant exhibited reduced leaf chlorophyll degradation following stress. In roots and leaves, the patterns of catalase (CAT), glutathione reductase (GR), ascorbate peroxidase (APX), guaiacol peroxidase (GPOX), superoxide dismutase (SOD) enzyme activity as well as malondialdehyde (MDA) and hydrogen peroxide (H2O2) production under the stressful conditions tested were very similar between MT and Nr mutant. However, Nr fruits showed increased H2O2 production, reduced and enhanced APX activity in NaCl and CdCl2, respectively, and enhanced GPOX in NaCl. Moreover, through non-denaturing PAGE, a similar reduction of SOD I band intensity in both, control MT and Nr mutant, treated with NaCl was observed. In leaves and fruits, a similar SOD activity pattern was observed for all periods, genotypes and treatments. Overall the results indicate that the ethylene signaling associated with NR receptor can modulate the biochemical pathways of oxidative stress in a tissue dependent manner, and that this signaling may be different following Na and Cd exposure.