INVESTIGADORES
BALESTRASSE Karina Beatriz
congresos y reuniones científicas
Título:
Heme oxygenase gene expression is modulated by nitric oxide in soybean plants
Autor/es:
NORIEGA, G; YANNARELLI, G; BALESTRASSE, K; BATLLE, A; TOMARO, M
Lugar:
Krakow, Poland
Reunión:
Congreso; The 5th Internacional Congress Heme Oxygenase 2007; 2007
Institución organizadora:
Department of Medical Biotechnology Faculty of Biotechnology Jagiellonian Univeristy Krakow, Poland
Resumen:
Heme oxygenase (HO, EC 1.14.99.3) catalyses the oxidative conversion of
heme to biliverdin IXa (BV) with the concomitant release of carbon monoxide and
iron. Recently, HO has been involved in the protection against oxidative stress
in plants . The fact that nitric oxide (NO), an endogenous signaling molecule
in animals and plants, mediates responses to abiotic and biotic stresses,
prompted us to study, whether this molecule could modulate HO-1 gene
transcription. To fulfill this objective leaves of soybean (Glycine max L.) plants were stimulated
with Cd, employing an acute intoxication model. Cadmium caused dehydration,
chlorophyll loss and ion leakage. Semi-quantitive RT-PCR analysis showed no
augmentation of HO-1 transcript levels with respect to controls. Pretreatment with
100 ìM sodium nitroprusiate (SNP), a well known NO donor, prevented the effects
caused by Cd. When the HO-1 mRNA levels were analyzed, a significant
augmentation (54%) was observed respect to Cd-treated plants. On the other
hand, 50 or 300 ìM SNP did not fully prevent the effects elicited by Cd. When
HO-1 transcript levels were analyzed, no significant enhancement or a
down-regulation was respectively observed. The potassium salt of
2-(4-carboxylphenyl)-4,4,5,5-tetramethylimidazoline1-oxyl-3-oxide (cPTIO), a specific
NO scavenger, arrested NO mediated protective effects against to Cd-induced oxidative
damage. These data provide an understanding of one of the possible roles that NO
can play against an oxidative insult. Nitric oxide is cytoprotective depending
on its concentration, and it was further demonstrated that this protection
could be, at least in part, mediated by an enhancement of HO-1 mRNA, as it
happens with genes associated with the antioxidant defense system.