A hydraulic signal in root-to-shoot signalling of water shortage
Article first published online: 16 AUG 2007
The Plant Journal
Volume 52, Issue 1, pages 167–174, October 2007
How to Cite
Christmann, A., Weiler, E. W., Steudle, E. and Grill, E. (2007), A hydraulic signal in root-to-shoot signalling of water shortage. The Plant Journal, 52: 167–174. doi: 10.1111/j.1365-313X.2007.03234.x
- Issue published online: 16 AUG 2007
- Article first published online: 16 AUG 2007
- Received 27 May 2007; accepted 12 June 2007.
- abscisic acid;
- water stress;
- drought stress;
- long-distance signal;
Photosynthesis and biomass production of plants are controlled by the water status of the soil. Upon soil drying, plants can reduce water consumption by minimizing transpiration through stomata, the closable pores of the leaf. The phytohormone abscisic acid (ABA) mediates stomatal closure, and is the assigned signal for communicating water deficit from the root to the shoot. However, our study does not support ABA as the proposed long-distance signal. The shoot response to limited soil water supply is not affected by the capacity to generate ABA in the root; however, the response does require ABA biosynthesis and signalling in the shoot. Soil water stress elicits a hydraulic response in the shoot, which precedes ABA signalling and stomatal closure. Attenuation of the hydraulic response in various plants prevented long-distance signalling of water stress, consistent with root-to-shoot communication by a hydraulic signal.