Dimethylthiourea, a hydrogen peroxide trap, partially prevents stress effects and ascorbate peroxidase increase in spermidine-treated maize roots.

Autor: De Zacchini, M., De Agazio, M.
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Zdroj: Plant, Cell & Environment; Feb2001, Vol. 24 Issue 2, p237, 8p, 3 Charts, 5 Graphs
Abstrakt: Inhibition of root growth and accumulation of putrescine caused by exogenous spermidine in roots of maize seedlings (Zea mays L., cv Samodek) were partially prevented by a concomitant treatment with dimethylthiourea (DMTU), that traps H[sub 2]O[sub 2] produced from spermidine by the activity of polyamine oxidase (PAO) in the apoplast. Treatment with spermidine caused a strong increase of ascorbate peroxidase (APX) gene expression, that was induced to a lesser extent by removing spermidine-generated H[sub 2]O[sub 2] by DMTU. Over-expression of APX was associated with increased APX activity in spermidine-treated seedlings whereas the addition of DMTU to spermidine completely prevented spermidine-induced increase of APX activity. Thus, DMTU permitted the demonstration that exogenous spermidine supplied to maize seedlings causes an oxidative stress and induces APX, a key enzyme of the antioxidant defence mechanism, through H[sub 2]O[sub 2], a spermidine catabolic product. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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