IQUIFIB   02644
INSTITUTO DE QUIMICA Y FISICOQUIMICA BIOLOGICAS "PROF. ALEJANDRO C. PALADINI"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Role of polyamines in the modulation of NADPH oxidase and catalase in Nicotiana tabacum leaves.
Autor/es:
IANNONE M.F.; ROSALES E.P.; GROPPA M.D.; BENAVIDES M.P.
Lugar:
Puerto Madryn, Chubut
Reunión:
Congreso; XLVI Reunión Anual- Sociedad Argentina de Investigación en Bioquímica y Biología Molecular.; 2010
Institución organizadora:
SAIB
Resumen:
ROL OF polYaminES IN THE MODULATION OF NADPH oxidasE AND catalasE IN NICOTIANA TABACUM LEAVES María F Iannone, Eliana P Rosales, Maria D. Groppa; María P Benavides Dpto de Química Biológica, FFyB, UBA. Junín 956, CABA, Argentina. Email: mflorenciaiannone@gmail.com Polyamines (PAs) are molecules implicated in plant growth, development and cell death. Previously, we observed that 1mM of putrescine (Put), spermidine (Spd), spermine (Spm) increased O2.- and H2O2 and cellular death in tobacco leaves at 24 h of exposure.The aim of this work was to evaluate the participation of NADPH oxidase in the generation of  O2.- and catalase (CAT) in the removal of  H2O2. We measured the enzymatic activity, gene expression of cat1 and Ntrboh and the protein content of catalase by WB. Leaf discs from 60-day-old wild type SR1 tobacco plants were treated for 2 and 24 h with 0.1mM or 1mM Put, Spm or Spd. All PAs concentrations tested increased the expression of NADPH oxidase at 2 h of exposure, but it decreased at 24 h, except 1mM Spm. However, the enzymatic activity decreased between 50% and 80%, with both concentrations of the 3 PAs at 2 and 24 h of treatment. Genetic expression of CAT increased at 2h with 1mM of PAs, but it decreased at 24 h. PAs diminished CAT activity at 2h. The protein expression of CAT raised over  50 and 30%, at 2 h,  with 1mM Put and 0.1 mM Spm, respectively, but at 24 h it was significantly reduced with both concentrations of Spd and Spm. These results show that at short times, the 3 PAs had a positive modulation in the genetic expression but a negative one in the activity of both enzymes. These suggest a post-transcriptional regulation of the enzymatic activity or a direct action over the enzyme. At long times, we observed that 1 mM Spm had an opposite effect than Put, suggesting that the induction of ROS generation and detoxification in tobacco could be regulated in a different way for each PA.