Abstract

Antarctica is considered one of the most extreme environments. Despite the extreme conditions, two vascular plants naturally inhabit: Colobanthus quitensis (Kunth) Bartl. and Deschampsia antarctica Desv. both colonize the Antarctica maritime territory. In terms of successfully, D. antarctica is described as the main colonizing vascular plant of Antarctica. In recent decades, due to global warming, the temperature of the Antarctica Peninsula has increased sustained and faster, more than the rest of the Antarctica continent and the world, registering an increase in temperature of 3.7 ºC during the last century. This condition promotes the growth and expansion of D. antarctica in the Antarctica maritime region. The increment in expansion of D. antarctica along Antarctica peninsula suggests that D. antarctica has biochemical mechanisms to confront the temperature increase. The high temperatures trigger signaling pathways that activate the expression of genes and synthesis of “stress related proteins”. Some specific to heat stress (“heat-shock proteins”, HSPs) and others to prevent the oxidative damage associated with heat. Plants produce a series of antioxidant enzymes for detoxify the reactive oxygen species (ROS). In this work was evaluated the response of D. antarctica cultivated in vitro to a short and long-time heat shock, determining the oxidative status (ROS content, membrane peroxidation and activity of the antioxidant enzymes superoxide dismutases, class III peroxidases, ascorbate peroxidases and catalases) and photosynthetic efficiency. Our results showed an induction of antioxidant activity to maintains the normal physiology of D. antarctica, suggesting that this specie is tolerant to heat shock of 10 ºC over optimal growth temperature.