Colobanthus quitensis differential proteomics

Global warming is strongly affecting the Maritime Antarctica climate and the consequent melting of perennial snow and ice covers resulted in increased colonization by plants. Colobanthus quitensis is a vascular plant highly adapted to the harsh environmental conditions of Antarctic Peninsula and understanding how the plant is responding to global warming is a new challenging target for modern cell physiology. To this aim, we performed differential proteomic analysis on C. quitensis plants grown in natural conditions compared to plants grown for one year inside Open Top Chambers (OTCs) which determine an increase of about 4 °C at midday, mimicking the effect of global warming. A thorough analysis of the up- and down-regulated proteins highlighted an extensive metabolism reprogramming leading to the hypothesis that (i) photorespiration could play an important role in reducing ROS-mediated photodamage improving OTC plants protection against photoinhibition; (ii) OTC plants activate stronger antioxidant defenses as confirmed by enzymatic activity and TBARS content measurement; (iii) the deposition of cell wall components is impaired in OTC plants due to the down-regulation of many enzymes involved in their biosyn-thesis; (iv) OTC plants could suffer of a reduced freezing tolerance due to lower concentration of soluble sugars acting as osmoprotectants.