PERSONAL DE APOYO
CAMPI Mabel
congresos y reuniones científicas
Título:
Participation of chromatin remodeling proteins in UV-B responses
Autor/es:
PAULA CASATI, LUCIANA D. LARIO, JULIA EMILIANI, MABEL CAMPI, VIRGINIA WALBOT Y JULIA QÜESTA
Lugar:
Glasgow, Reino Unido
Reunión:
Congreso; Annual Main Meeting of the Society for Experimental Biology; 2009
Institución organizadora:
Society for Experimental Biology
Resumen:
<!--
@page { margin: 2cm }
P { margin-bottom: 0.21cm }
-->
Terrestrial life evolved after the
ozone layer formed and could absorb most damaging UV-B in solar
radiation. Chromatin remodeling in response to UV-B has been
implicated in maize; in addition, several chromatin proteins are also
UV-B regulated in Arabidopsis. Therefore, chromatin remodeling
capacity appears to be a key process for effective responses to UV-B.
ChIP assays were done to monitor chromatin status at several UV-B
responsive genes: the promoter and transcribed regions in tolerant
maize lines showed different chromatin protein association after UV-B
than sensitive lines. Chromatin status was also investigated at
terminal inverted repats of the mutator transposon in maize, both in
active and silencing states: reactivation by UV-B is accompanied by
histone and DNA demethylation, correlating with an increase in MuRA
and B transcripts. On the other hand, UV-B causes the
formation of photoproducts in DNA, wich affects the structural and
dynamic properties of chromatin. To investigate the role of different
chromatin remodeling proteins in DNA repair, Arabidopsis T-DNA
mutants, and maize and arabidopsis RNAi plants were analyzed. Several
chromatin deficient plants (maize chc101, mbd101,sdg102 and nfc102; and Arabidopsis sdg26)
showed increased UV-B-induced DNA damage; while others (Arabidopsischc1) did not show significant differences with WT plants. On
the contrary, ros1 mutants showed increased tolerance to DNA
damage, suggesting that chromatin proteins regulate different aspects
of DNA repair in plants. Our results indicate that chromatin
remodeling is a key process in acclimation to UV-B and that plants
deficient in this process are more sensitive to UV-B.