Role of chromatin remodeling proteins in UV-B responses in plants

PAULA CASATI

Rosario

Congreso; L Reunión Anual de la Sociedad Argentina de Bioquímica y Biología Molecular; 2014

Terrestrial life evolved only after the stratospheric ozone layer formed and could absorb most damaging UV-B (280-315 nm) in solar radiation. The strong absorption of UV-B by biological molecules, particularly DNA, makes this radiation extremely dangerous. Because plants must absorb photons to power photosynthesis, they are inevitably exposed to damaging UV-B. As a result, they have evolved diverse responses to this type of radiation. Chromatin remodeling in response to UV-B has been implicated in plants. Chromatin conformation on DNA can have a role in the regulation of the expression of different genes: proteins that function in chromatin remodeling can activate or repress transcription recruiting co-regulators, or changing the structure of promoter regions, and thus affecting the interaction with the transcripcional machinery. On the other hand, the package of DNA in the chromatin affects the structure and accessibility of DNA, and therefore the velocity of formation and repair of damage in DNA molecules. Thus, we explored the role of chromatin proteins in UV-B stress. In particular, we investigated the role of histone acetylation in UV-B responses and the function of chromatin proteins in cell cycle regulation. Our results indicate that chromatin remodeling is a key process in acclimation to UV-B treatment and that lines deficient in this process are more sensitive to UV-B.