INVESTIGADORES
CASATI Paula
artículos
Título:
Repression of Growth Regulating Factors by the microRNA miR396 inhibits cell proliferation by UV-B in Arabidopsis thaliana leaves
Autor/es:
ROMINA CASADEVALL; RAMIRO RODRIGUEZ VIRASORO; JUAN MANUEL DEBERNARDI; JAVIER PALATNIK; PAULA CASATI
Revista:
PLANT CELL
Editorial:
AMER SOC PLANT BIOLOGISTS
Referencias:
Lugar: Rockville; Año: 2013 p. 3570 - 3583
ISSN:
1040-4651
Resumen:
Because of their sessile lifestyle, plants are continuously exposed to solar UV-B radiation. Inhibition of leaf growth is one of the most consistent responses of plant exposure to UV-B. In this work, we have investigated the role of GROWTH-REGULATING FACTORS (GRFs) and of microRNA miR396 in UV-B-mediated inhibition of leaf growth in Arabidopsis thaliana plants. We demonstrate that miRNA396 is up-regulated by UV-B radiation in proliferating tissues and that this induction is correlated with a decrease in GRF1, GRF2 and GRF3 transcripts. Induction of miR396 results in inhibition of cell proliferation, and this outcome is independent of the UV-B photoreceptor UVR8, ATR and MPK6, but dependent on MPK3. Transgenic plants expressing an artificial target mimic directed against miR396 (MIM396) to decrease the endogenous miRNA activity or plants expressing miR396-resistant copies of several GRFs are less sensitive to this inhibition. Consequently, at intensities that can induce DNA damage in Arabidopsis plants, UV-B limits leaf growth by inhibiting cell division in proliferating tissues, a process mediated by miR396 and GRFs.