The until now characterised plant polyamine oxidases (PAO), such as the apoplastic maize PAO (ZmPAO), are involved in the terminal catabolism of spermine (Spm) and spermidine (Spd), contrary to the animal PAOs which oxidise Spm and Spd through a polyamine back-conversion pathway. In Arabidopsis thaliana, five putative PAO genes (AtPAO1-5) are present with a varying sequence homology (23%-45%) to ZmPAO and predicted subcellular localization (cytosolic and peroxisomal). Biochemical characterization of recombinant AtPAO1, AtPAO2 and AtPAO4 showed that these enzymes are active not only towards the common polyamines Spd and Spm, but also towards the stress-related uncommon polyamines thermine and thermospermine. It was also demonstrated that these enzymes participate in a polyamine back-conversion pathway which was indeed detected in vivo. Characterization of Arabidopsis knock out mutants and Arabidopsis plants transformed with 35SCaMVprom:AtPAO, AtPAOprom:GUS and 35SCaMVprom:AtPAOGFP constructs for all AtPAOs is in progress both under physiological and environmental stress conditions to obtain information on AtPAO expression pattern, subcellular localization and physiological role.
Pomettini, L., Spedaletti, V., Leone, M., RICCI MARIA, E., Tavazza, R., Angelini, R., et al. (2008). POLYAMINE CATABOLISM IN ARABIDOPSIS THALIANA. In Atti del 47° Congresso della Società Italiana di Fisiologia Vegetale (pp.59).
POLYAMINE CATABOLISM IN ARABIDOPSIS THALIANA
SPEDALETTI, VALENTINA;ANGELINI, Riccardo;FEDERICO, Rodolfo;TAVLADORAKI, Paraskevi
2008-01-01
Abstract
The until now characterised plant polyamine oxidases (PAO), such as the apoplastic maize PAO (ZmPAO), are involved in the terminal catabolism of spermine (Spm) and spermidine (Spd), contrary to the animal PAOs which oxidise Spm and Spd through a polyamine back-conversion pathway. In Arabidopsis thaliana, five putative PAO genes (AtPAO1-5) are present with a varying sequence homology (23%-45%) to ZmPAO and predicted subcellular localization (cytosolic and peroxisomal). Biochemical characterization of recombinant AtPAO1, AtPAO2 and AtPAO4 showed that these enzymes are active not only towards the common polyamines Spd and Spm, but also towards the stress-related uncommon polyamines thermine and thermospermine. It was also demonstrated that these enzymes participate in a polyamine back-conversion pathway which was indeed detected in vivo. Characterization of Arabidopsis knock out mutants and Arabidopsis plants transformed with 35SCaMVprom:AtPAO, AtPAOprom:GUS and 35SCaMVprom:AtPAOGFP constructs for all AtPAOs is in progress both under physiological and environmental stress conditions to obtain information on AtPAO expression pattern, subcellular localization and physiological role.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
