Local and systemic regulation of sulfur homeostasis in roots of Arabidopsis thaliana
Article first published online: 20 SEP 2012
© 2012 The Authors. The Plant Journal © 2012 Blackwell Publishing Ltd
The Plant Journal
Volume 72, Issue 4, pages 625–635, November 2012
How to Cite
Hubberten, H.-M., Drozd, A., Tran, B. V., Hesse, H. and Hoefgen, R. (2012), Local and systemic regulation of sulfur homeostasis in roots of Arabidopsis thaliana. The Plant Journal, 72: 625–635. doi: 10.1111/j.1365-313X.2012.05105.x
- Issue published online: 2 NOV 2012
- Article first published online: 20 SEP 2012
- Accepted manuscript online: 9 JUL 2012 12:01PM EST
- Received 11 November 2010; revised 2 July 2012; accepted 6 July 2012; published online 20 September 2012.
- split root;
- systemic signal;
Nutrients are limiting for plant growth and vigour. Hence, nutrient uptake and homeostasis must be adjusted to the needs of the plant according to developmental stages and environmental conditions. A split-root system was applied to analyse the systemic and local response of Arabidopsis thaliana to sulfur starvation. Arabidopsis thaliana plants in which only one root half was starved while the other root half was supplied with sulfate were analysed at the metabolic and transcriptional level. No systemic induction of sulfate uptake or expression of sulfate starvation marker genes was observed in split-roots sufficiently supplied with sulfate. Our data suggest that no activation of sulfur uptake takes part in sulfur-supplied root patches when the general sulfur status declines. When comparing roots of fully sulfate-starved plants with sulfate-starved split-root roots, expression of several potentially OAS responsive genes was attenuated in split-roots depending on the shoot sulfate status and the local root O-acetylserine concentration. In contrast, high-affinity sulfate transporters displayed similar expression in sulphate-starved split-roots and the corresponding controls. Feeding of 35SO42− to the shoot or to either part of a split-root system revealed that sulfate is the most prominent mobile sulfur-containing compound within the plant. Hence, we postulate a model whereby the soil sulfate availability regulates the sulfate uptake system of roots while the shoot sulfur status modulates the local O-acetylserine response in the root by passive ‘plant sulfur status-dependent’ transport of sulfate.