The Arabidopsis det3 mutant reveals a central role for the vacuolar H+–ATPase in plant growth and development
- Howard Hughes Medical Institute and Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037 USA; Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742 USA; Department of Agronomy and Range Science, University of California, Davis, California 95616 USA
Abstract
In all multicellular organisms growth and morphogenesis must be coordinated, but for higher plants, this is of particular importance because the timing of organogenesis is not fixed but occurs in response to environmental constraints. One particularly dramatic developmental juncture is the response of dicotyledonous seedlings to light. The det3 mutant of Arabidopsis develops morphologically as a light-grown plant even when it is grown in the dark. In addition, it shows organ-specific defects in cell elongation and has a reduced response to brassinosteroids (BRs). We have isolated the DET3 gene by positional cloning and provide functional and biochemical evidence that it encodes subunit C of the vacuolar H+–ATPase (V-ATPase). We show that the hypocotyl elongation defect in the det3 mutant is conditional and provide evidence that this is due to an alternative mechanism of V-ATPase assembly. Together with the expression pattern of the DET3 gene revealed by GFP fluorescence, our data provide in vivo evidence for a role for the V-ATPase in the control of cell elongation and in the regulation of meristem activity.
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↵Corresponding author.
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E-MAIL chory{at}salk.edu; FAX (858) 558-6379.
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- Received September 22, 1999.
- Accepted October 28, 1999.
- Cold Spring Harbor Laboratory Press
