Polyamine catabolism is involved in response to salt stress in soybean hypocotyls

MARÍA PAULA CAMPESTRE; CESAR DANIEL BORDENAVE; ANDREA CECILIA ORIGONE; ANA BERNARDINA MENÉNDEZ; OSCAR ADOLFO RUIZ; ANDRÉS ALBERTO RODRÍGUEZ; SANTIAGO JAVIER MAIALE

JOURNAL OF PLANT PHYSIOLOGY

ELSEVIER GMBH

Año: 2011 vol. 168 p. 1234 - 1240

0176-1617

The possible relationship between polyamine catabolism mediated by copper-containing amineoxidase and the elongation of soybean hypocotyls from plants exposed to NaCl has been studied.Salt treatment reduced values of all hypocotyl growth parameters. In vitro, copper-containingamine oxidase activity was up to 77-fold higher than that of polyamine oxidase. This enzymepreferred cadaverine over putrescine and it was active even under the saline condition. On theother hand, saline stress increased spermine and cadaverine levels, and the in vivo coppercontainingamine oxidase activity in the elongation zone of hypocotyls. The last effect wasnegatively modulated by the addition of the copper-containing amine oxidase inhibitor N,N´-diaminoguanidine. In turn, plants treated with the inhibitor showed a significant reduction ofreactive oxygen species in the elongation zone, even in the saline situation. In addition, plantsgrown in cadaverine-amended culture medium showed increased hypocotyl length either in salineor control conditions and this effect was also abolished by N,N´-diaminoguanidine. Taken together,our results suggest that the activity of the copper-containing amine oxidase may be partiallycontributing to hypocotyl growth under saline stress, through the production of hydrogen peroxideby polyamine catabolism and reinforce the importance of polyamine catabolism and hydrogenperoxide production in the induction of salt tolerance in plants.