Response of the heme oxygenase of soybean nodules to drought stress

BARCIA R; SANTA CRUZ DM; BALESTRASSE KB; TOMARO ML

Miami Beach, Florida

Congreso; Heme Oxygenases in Biology and Medicine, 6th International Congress on Heme Oxygenases; 2009

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:ES; mso-fareast-language:ES;} @page Section1 {size:595.3pt 841.9pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Drought stress is among the most serious challenges to crop production worldwide. Upon exposure of plants to drought conditions, many stress-related genes are induced and their products are thought to function as cellular protectants of stress-induced damage. The aim of this study was to evaluate whether there is a link between drought stress and soybean plants nodules heme oxygenase (HO-1) behaviour. To this purpose, soybean plants inoculated with Bradyrhizobium japonicum. After 30 days growth they were subjected to drought for 5 days. Under this condition no difference was found in TBARS content respect to controls. Nevertheless, an increase of catalase (CAT) activity (60%) was observed. No induction of heme oxygenase-1 gene expression was detected, as demonstrated by RT-PCR analysis. To further investigate the effect of drought was performed with plants exposed to 10 days without Hoagland. Under this condition, there is an augmentation in TBARS levels (45%), beside CAT activity increase by 20% respect to controls and HO-1 gene expression was enhanced by 40%. After these plants were recovered for 6 days using Hoagland solution. Results obtained showed that no production of TBARS occurred, whereas an increase in CAT activity (30% respects to controls) and HO-1 gene expression (35% respect to controls) were evidenced. These results let us assume that HO-1 gene response to drought after 10 days of drought when lipid peroxidation is increase. On the other hand, CAT and HO- reduced the damage oxidative in soybean nodules after 6 days recovery.