CNR ExploRA

Articolo in rivista, 2012, ENG, 10.1242/dev.078212

COP1 mediates the coordination of root and shoot growth by light through modulation of PIN1- and PIN2-dependent auxin transport in Arabidopsis.

Sassi M (1,2), Lu Y (3), Zhang Y (4), Wang J (3), Dhonukshe P (5), Blilou I (5), Dai M (6), Li J (4), Gong X (3), Jaillais Y (1), Yu X (7), Traas J (1), Ruberti I (2), Wang H (6), Scheres B (5), Vernoux T (1), Xu J (3,4,5).

(1) CNRS, INRA, ENS Lyon, UCBL, Université de Lyon, Laboratoire de Reproduction et Développement des Plantes, 46 Allée d'Italie, 69364 Lyon Cedex 07, France. (2) Istituto di Biologia e Patologia Molecolari, CNR, Piazzale Aldo Moro 5, 00185 Rome, Italy. (3) Department of Biological Sciences and NUS Centre for BioImaging Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543. (4) National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China. (5) Department of Molecular Genetics, Utrecht University, Padualaan 8, 3584CH Utrecht, The Netherlands. (6) Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520-8104, USA. (7) Department of Biology, Indiana University, Bloomington, IN 47405, USA.

When a plant germinates in the soil, elongation of stem-like organs is enhanced whereas leaf and root growth is inhibited. How these differential growth responses are orchestrated by light and integrated at the organismal level to shape the plant remains to be elucidated. Here, we show that light signals through the master photomorphogenesis repressor COP1 to coordinate root and shoot growth in Arabidopsis. In the shoot, COP1 regulates shoot-to-root auxin transport by controlling the transcription of the auxin efflux carrier gene PIN-FORMED1 (PIN1), thus appropriately tuning shoot-derived auxin levels in the root. This in turn directly influences root elongation and adapts auxin transport and cell proliferation in the root apical meristem by modulating PIN1 and PIN2 intracellular distribution in the root in a COP1-dependent fashion, thus permitting a rapid and precise tuning of root growth to the light environment. Our data identify auxin as a long-distance signal in developmental adaptation to light and illustrate how spatially separated control mechanisms can converge on the same signaling system to coordinate development at the whole plant level.

Development (Camb. Online) 139 , pp. 3402–3412