POLYAMINE CATABOLISM IN THE ELONGATION ZONE CONTRIBUTES TO SUSTAIN SOYBEAN HYPOCOTYLS GROWTH UNDER SALINE STRESS

CAMPESTRE MARIA; MAIALE SANTIAGO; BORDENAVE CESAR; ORIGONE ANDREA; RUIZ OSCAR; RODRÍGUEZ ANDRÉS

La Plata, Pcia Bs.As.

Congreso; RAFV 2010; 2010

SAFV

Objetive:The possible relationship between polyamine catabolism by copper-containing amine oxidase and hypocotyl growth of salinized soybean has been studied. Results: Salt treatment increased spermine and mainly, cadaverine level in hypocotyls. Copper-containing amine oxidase activity level was up to 77-fold higher that of the polyamine oxidase. Copper-containing amine oxidase was active even in salinity and showed highest affinity to cadaverine than putrescine. In vivo determination of copper-containing amine oxidase activity in presence of cadaverine, showe an increase with saline treatment modulated negatively in treatment added with diaminoguanidine,a competitive inhibitor. The same effects of cadaverine and diaminoguanidine were observed in hypocotyl growth assays of under optimal or unfavourable conditions. Additionally, plants treated with diaminoguanidine showed a signiticative reduction of reactive oxygen species in the elongation zone of hypocotyl detected by DCF fluorescence. Conclusions: These results demostrated that copper-containing amine oxidase activity produced hydrogen peroxide by polyamine catabolism in salinity and this hydrogen peroxide production may be contributing to hypocotyl growth partially under saline stress.