Facultad de Agronomia - UBA

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Acceso al documento : Documento de Acceso Restringido. Disponible sólo para la Comunidad FAUBA.
URL al registro : http://ri.agro.uba.ar/cgi-bin/library.cgi?a=d&c=arti&d=2016goyal
Tipo de material : Artículo
Autores : Goyal, Anupama; Karayekov, Elizabeth; Galvao, Vinicius Costa; Ren, Hong; Casal, Jorge José; Fankhauser, Christian
Título en inglés : Shade promotes Phototropism through Phytochrome B-controlled Auxin production
Fuente : Current biology
Año : 2016
Volumen y número : Vol.26
Temas : PHOTOTROPISM; SHADE AVOIDANCE; PHOTORECEPTOR CROSSTALK; PHITOTROPIN 1; PHYTOCHROME B; PHYTOCHROME INTERACTING FACTORs; YUCCAS; ARABIDOPSIS THALIANA
Idioma : inglés
Descripción : grafs.
Páginas :  p.3280–3287
Resumen : Phototropism is an asymmetric growth response enabling plants to optimally position their organs. In flowering plants, the phototropin (phot) blue light receptors are essential to detect light gradients. In etiolated seedlings, the phototropic response is enhanced by the red/far-red (R/FR)-sensing phytochromes (phy) with a predominant function of phyA. In this study, we analyzed the influence of the phytochromes on phototropism in green (deetiolated) Arabidopsis seedlings. Our experiments in the laboratory and outdoors revealed that, in open environments (high R/FR ratio), phyB inhibits phototropism. In contrast, under foliar shade, where access to direct sunlight becomes important, the phototropic response was strong. phyB modulates phototropism, depending on the R/FR ratio, by controlling the activity of three basic-helix-loop-helix (bHLH) transcription factors of the PHYTOCHROME INTERACTING FACTORs (PIFs) family. Promotion of phototropism depends on PIF-mediated induction of several members of the YUCCA gene family, leading to auxin production in the cotyledons. Our study identifies PIFs and YUCCAs as novel molecular players promoting phototropism in photoautotrophic, but not etiolated, seedlings. Moreover, our findings reveal fundamental differences in the phytochrome-phototropism crosstalk in etiolated versus green seedlings. We propose that in natural conditions where the light environment is not homogeneous, the uncovered phytochrome-phototropin co-action is important for plants to adapt their growth strategy to optimize photosynthetic light capture.
DOI : 10.1016/j.cub.2016.10.001
Link al editor : https://www.cell.com/
Cita recomendada : Goyal, A.; Karayekov, E.; Galvao, V. C.; Ren, H.; Casal, J. J.; & Fankhauser, C. (2016). Shade promotes Phototropism through Phytochrome B-controlled Auxin production. Current biology‚ 26‚  p.3280–3287. Doi: 10.1016/j.cub.2016.10.001.
 
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