The cellular response to stress also includes the accumulation of reactive oxygen species (ROS). When in excess, these second messengers can cause significant detrimental biochemical changes, such as stress-induced lipid peroxidation. In plants, a powerful endogenous antioxidant system is based on the enzymatic modification of redox-sensitive cysteines, carried out for example, by thioredoxin proteins. In this work, we report the cloning and characterization of a thioredoxin gene from olive (Olea europaea L.), which was named Oe-Trx h I. We also performed an expression analysis in drupes following biotic stress, as a first step towards the definition of its possible defensive role against the olive fruit fly [Bactrocera oleae (Rossi)]. The data indicate that the cloned thioredoxin h is a potential member of the biotic stress response in drupes and suggest that Oe-Trx h I may be a component active towards an increased resistance against oxidative stress. This work opens the way to further studies to assess the protective role of this gene against ROS accumulation and lipid peroxidation in drupes following larval feeding.
Keywords: biotic stress, cloning, drupes, gene expression, Olea europaea, stress response