Copper amine oxidases (CuAOs) catalyse the oxidation of polyamines to aminoaldehydes, producing ammonia and hydrogen peroxide (H2O2). CuAOs are induced by stress-related hormones such as methyljasmonate and abscisic acid (ABA). In this study, we have analysed the role played by an Arabidopsis CuAO, AtCuAOδ, in the ABAmediated stomatal closure. ABA induced AtCuAOδ-gene expression at two different concentrations (10μM, 100μM). Moreover, ABA-induced stomatal closure was analysed in atcuaoδ T-DNA insertional mutant lines. Under physiological conditions no differences between WT and mutants were observed, while mutants were less responsive to ABAinduced stomatal closure. Treatment with the H2O2 scavenger N,N1- dimethylthiourea reversed in part the ABA-induced stomatal closure in WT plants. Moreover, H2O2, normally detected in guard cells of WT plants upon ABA treatment, was absent in guard cells of ABA treated mutants. AtCuAOδ over-expressing plants showed an increase in stomatal closure level along with a detectable H2O2 production in guard cells under normal growth conditions. These data suggest that AtCuAOδ may play a role as H2O2 source in ABA-induced stomatal closure.
AtCuAOδ participates in abscisic acid-induced stomatal closure in Arabidopsis
RODRIGUES POUSADA, RENATO ALBERTO;
2016-01-01
Abstract
Copper amine oxidases (CuAOs) catalyse the oxidation of polyamines to aminoaldehydes, producing ammonia and hydrogen peroxide (H2O2). CuAOs are induced by stress-related hormones such as methyljasmonate and abscisic acid (ABA). In this study, we have analysed the role played by an Arabidopsis CuAO, AtCuAOδ, in the ABAmediated stomatal closure. ABA induced AtCuAOδ-gene expression at two different concentrations (10μM, 100μM). Moreover, ABA-induced stomatal closure was analysed in atcuaoδ T-DNA insertional mutant lines. Under physiological conditions no differences between WT and mutants were observed, while mutants were less responsive to ABAinduced stomatal closure. Treatment with the H2O2 scavenger N,N1- dimethylthiourea reversed in part the ABA-induced stomatal closure in WT plants. Moreover, H2O2, normally detected in guard cells of WT plants upon ABA treatment, was absent in guard cells of ABA treated mutants. AtCuAOδ over-expressing plants showed an increase in stomatal closure level along with a detectable H2O2 production in guard cells under normal growth conditions. These data suggest that AtCuAOδ may play a role as H2O2 source in ABA-induced stomatal closure.Pubblicazioni consigliate
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