FRANSCICO GASULLA, RENUKA JAIN, EVA BARRENO, ALFREDO GUÉRA, TIAGO S. BALBUENA, JAY J. THELEN and MELVIN J. OLIVER
Our understanding of desiccation tolerance in lichens, and of their chlorobionts, was limited to the ability of the antioxidant system to protect cells from photo-oxidative and dehydration induced damage. He intent of this investigation was to determine how desiccation tolerance in the algal partner, Asterochloris erici, of the symbiosis was broadly controlled, a critical missing piece of information in our understanding of the evolution of this important trait in plants. Using a proteomic approach, along with targeted transcript profiling, we were able to demonstrate that only a small number of proteins, including Hsp90s and β-tubulins, were positively enhanced during dehydration indicating that the desiccation tolerance in the alga is primarily constitutive. These conclusions were consistent with ultrastructural observations that revealed extensive damage, especially when drying rates were rapid, that the alga survived without a major alteration of the proteome.