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

by Sassi, M, Lu, Y, Zhang, YH, Wang, J, Dhonukshe, P, Blilou, I Dai, MQ, Li, J, Gong, XM, Jaillais, Y, Yu, XH, Traas, J, Ruberti, I, Wang, HY, Scheres, B, Vernoux, T and Xu, Jian

Development 139, 3402-3412 (2012)

Although the roots of most plant species are not directly exposed to light, root growth is controlled by light and integrated with the growth of above-ground organs. We uncover a novel long-distance mechanism by which light signals through the master photomorphogenesis repressor COP1 to coordinate root and shoot development in Arabidopsis. We show that, in the shoot, COP1 regulates shoot-to-root transport of auxin by controlling transcription of the auxin efflux carrier gene PIN-FORMED1 (PIN1). Whereas in the root apical meristem COP1 regulates auxin transport and cell proliferation by modulating the intracellular distribution of PIN1 and PIN2 in the root, thereby ensuring rapid and precise tuning of root growth to the light environment.

Together, our results identify auxin as a long-distance signal in light-regulated plant development and show how spatially separated control mechanisms can converge on a single signalling system to coordinate development at the whole plant level.

Read online: Pubmed.

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