Drought regulation of GST8, encoding the Arabidopsis homologue of ParC/Nt107 glutathione transferase/peroxidase.
Glutathione transferases (GST; EC 2.5.1.18) have been involved in many biotic and abiotic interactions of plants with their environment, but very little information is available on their regulation and possible role in drought tolerance. The GST8 gene of Arabidopsis thaliana encodes, as assessed by phylogenetic analysis, the homologue of an extremely conserved subgroup of Tau GSTs. During rapid dehydration of seedlings and progressive drought stress of mature plants, GST8 transcript levels increased following slower kinetics than RNAs for dehydration responsive genes RD29A and B, and strictly paralleled, in a mostly ABA independent manner, expression of oxidative stress marker PRX. GST8 RNA levels were also consistently increased by oxidative stress, high doses of auxin or cytokinin, and to a lesser extent, by wounding. RNA levels of ERD13, a previously described rapid dehydration responsive GST of the Phi class, were not co-regulated with those of GST8. Our results suggest that a drought-associated oxidative stress induces accumulation of GST8, whose function could be to counteract the effect of higher ROS production in stressed plants
Biologie Cellulaire et Moléculaire de l'Adaptation à la Sécheresse, Faculté des Sciences et Technologie, Université Paris XII-Val de Marne, 61 Avenue General de Gaulle, 94010 Créteil, France Institut des Sciences du Végétal, UPR 40 CNRS, 91198 Gif-sur-Yvette cedex, France.
Michele W
MW
Bianchi
Camille
C
Roux
Nicole
N
Vartanian