These authors contributed equally to this work.
The WAVY GROWTH 3 E3 ligase family controls the gravitropic response in Arabidopsis roots
Article first published online: 5 JAN 2012
© 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd
The Plant Journal
Volume 70, Issue 2, pages 303–314, April 2012
How to Cite
Sakai, T., Mochizuki, S., Haga, K., Uehara, Y., Suzuki, A., Harada, A., Wada, T., Ishiguro, S. and Okada, K. (2012), The WAVY GROWTH 3 E3 ligase family controls the gravitropic response in Arabidopsis roots. The Plant Journal, 70: 303–314. doi: 10.1111/j.1365-313X.2011.04870.x
- Issue published online: 3 APR 2012
- Article first published online: 5 JAN 2012
- Accepted manuscript online: 28 NOV 2011 01:55PM EST
- Received 23 October 2011; accepted 22 November 2011; published online 5 January 2012.
- E3 ligase;
- RING finger protein;
Regulation of the root growth pattern is an important control mechanism during plant growth and propagation. To better understand alterations in root growth direction in response to environmental stimuli, we have characterized an Arabidopsis thaliana mutant, wavy growth 3 (wav3), whose roots show a short-pitch pattern of wavy growth on inclined agar medium. The wav3 mutant shows a greater curvature of root bending in response to gravity, but a smaller curvature in response to light, suggesting that it is a root gravitropism-enhancing mutation. This wav3 phenotype also suggests that enhancement of the gravitropic response in roots strengthens root tip impedance after contact with the agar surface and/or causes an increase in subsequent root bending in response to obstacle-touching stimulus in these mutants. WAV3 encodes a protein with a RING finger domain, and is mainly expressed in root tips. RING-containing proteins often function as an E3 ubiquitin ligase, and the WAV3 protein shows such activity in vitro. There are three genes homologous to WAV3 in the Arabidopsis genome [EMBRYO SAC DEVELOPMENT ARREST 40 (EDA40), WAVH1 and WAVH2 ], and wav3 wavh1 wavh2 triple mutants show marked root gravitropism abnormalities. This genetic study indicates that WAV3 functions positively rather than negatively in root gravitropism, and that enhancement of the gravitropic response in wav3 roots is dependent upon the function of WAVH2 in the absence of WAV3. Hence, our results demonstrate that the WAV3 family of proteins are E3 ligases that are required for root gravitropism in Arabidopsis.