CEFOBI   05405
CENTRO DE ESTUDIOS FOTOSINTETICOS Y BIOQUIMICOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
“ROLE OF CHROMATIN REMODELING PROTEINS IN THE UV-B RESPONSE OF PLANTS”
Autor/es:
CAMPI M.; EMILIANI J.; CASATI P.
Lugar:
Mar del plata
Reunión:
Congreso; XLIII Reunión Annual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2007
Resumen:
ROLE OF CHROMATIN REMODELING PROTEINS IN THE UV-B RESPONSE OF PLANTS Campi, Mabel; Emiliani, Julia; Casati, Paula. CEFOBI. Fac. Cs. Bioq. y Farm. UNR. Suipacha 531. 2000.Rosario. Argentina. e-mail:campi@cefobi.gov.ar UV-B radiation affects plant development and physiology. UV-B causes the formation of photoproducts in DNA, which affects the structural and dynamic properties of chromatin. In maize, genes encoding chromatin remodeling proteins are regulated by UV-B, including chc101, nfc 102 and sdg102. A. thaliana chc1, nfc4 and sdg26 genes are the homologues to those from maize; we measured mRNA levels after 4 h-UV-B exposure: transcripts are induced for all genes. To investigate the role of each protein in UV-B responses, T-DNA mutants and RNAi plants were analyzed; they show null or decreased transcript levels compared to WT plants. Flavonoid levels increased in WT plants by UV-B (54%). However, chc101 deficient plants showed a smaller increase (24%); while in nfc 102 and sdg10, flavonoids are unchanged. Thus, these plants have altered regulation of UV sunscreen accumulation. Chlorophyll levels also varied among lines: chc1 mutants showed a decrease of 55% by UV-B, while WT, sdg26 and nfc4 deficient plants show unchanged chl levels by UV-B. However, although preliminary, CO2 fixation in sdg26 mutants seems to be more affected by UV-B than in WT plants. Together, Arabidopsis plants with null or decreased levels of transcripts encoding chromatin remodeling factors exhibit increased UV-B sensitivity. DNA damage and UV-B regulation of marker genes in these plants are under study.