COMPARATIVE RESPONSE OF HEMO OXYGENASE OF SOYBEAN NODULES TO SALT AND DROUGHT STRESS

ZILLI CG; BARCIA RA; BALESTRASSE KB

Tucumán

Congreso; 1. XLV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2009

Heme oxygenase-1 (HO-1) induction plays a protective role in plantcells against oxidative stress. Salt and drought stress are among themost serious challenges to crop production worldwide. The aim ofthis study was to evaluate whether there is a link between droughtand salt stress with soybean plants nodules HO-1 behavior. After 30days growth, plants were subjected to salt and drought for 10 days.Under drought stress, there is an augmentation in TBARS levels(45%), CAT activity decreased by 20% and HO-1 protein levelswere enhanced by 40%, respect to controls. Treatment with 100 mMNaCl increased TBARS levels (29%), CAT activity decreased by30% and protein overexpression occurred, respect to controls. It isinteresting to note that under 100 mM NaCl and drought stress CATactivity was inhibited, while HO is markedly increased.Salt and drought treatments on nitrogen assimilation, glutaminesynthetase (GS) and NADH-glutamate synthase (GOGAT) proteinlevels were evaluated. Both enzymes increased in droughtconditions. GS remained similar to control and GOGAT increasedprotein levels with salt. In addition, HO activity and proteinexpression were significantly increased under salt and droughttreatments.Our data demonstrated that the up-regulation of HO could beprotecting the soybean nodule nitrogen assimilation under salineand drought stress conditions.