Present address: Department of Botany and Plant Sciences, Institute for Integrative Genome Biology, Center for Plant Cell Biology, University of California, Riverside, CA 92521, USA.
Identification of the Arabidopsis dry2/sqe1-5 mutant reveals a central role for sterols in drought tolerance and regulation of reactive oxygen species
Article first published online: 1 APR 2009
© 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Ltd
The Plant Journal
Volume 59, Issue 1, pages 63–76, July 2009
How to Cite
Posé, D., Castanedo, I., Borsani, O., Nieto, B., Rosado, A., Taconnat, L., Ferrer, A., Dolan, L., Valpuesta, V. and Botella, M. A. (2009), Identification of the Arabidopsis dry2/sqe1-5 mutant reveals a central role for sterols in drought tolerance and regulation of reactive oxygen species. The Plant Journal, 59: 63–76. doi: 10.1111/j.1365-313X.2009.03849.x
- Issue published online: 25 JUN 2009
- Article first published online: 1 APR 2009
- Received 11 December 2008; revised 9 February 2009; accepted 17 February 2009; published online 1 April 2009.
- squalene epoxidase;
- sterol biosynthesis;
- drought tolerance;
- NADPH oxidase;
- reactive oxygen species
Squalene epoxidase enzymes catalyse the conversion of squalene into 2,3-oxidosqualene, the precursor of cyclic triterpenoids. Here we report that the Arabidopsis drought hypersensitive/squalene epoxidase 1-5 (dry2/sqe1-5) mutant, identified by its extreme hypersensitivity to drought stress, has altered stomatal responses and root defects because of a point mutation in the SQUALENE EPOXIDASE 1 (SQE1) gene. GC-MS analysis indicated that the dry2/sqe1-5 mutant has altered sterol composition in roots but wild-type sterol composition in shoots, indicating an essential role for SQE1 in root sterol biosynthesis. Importantly, the stomatal and root defects of the dry2/sqe1-5 mutant are associated with altered production of reactive oxygen species. As RHD2 NADPH oxidase is de-localized in dry2/sqe1-5 root hairs, we propose that sterols play an essential role in the localization of NADPH oxidases required for regulation of reactive oxygen species, stomatal responses and drought tolerance.