Mechanotransduction in gravisensing cells

• Published in: Trends in plant science Vol. 8; no. 10; pp. 498 - 504
• Main Authors: Perbal, Gérald, Driss-Ecole, Dominique
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.10.2003; Elsevier
• Subjects: Biological and medical sciences; Cell Polarity; Fundamental and applied biological sciences. Psychology; Gravitropism - physiology; Mechanoreceptors - physiology; Movements; Plant physiology and development; Plant Roots - cytology; Plant Roots - physiology; Signal Transduction - physiology; Space life sciences; Translocation; Signal transduction; Vegetals; Auxin; Calcium; Amyloplast; Ion transport; Gravitropism; Statolith; Review; Gravity
• ISSN: 1360-1385; 1878-4372
• DOI: 10.1016/j.tplants.2003.09.005

Plant organs can re-orientate themselves with respect to gravity. Gravisensing cells (statocytes) contain movable amyloplasts whose potential energy is apparently used to activate calcium channels by exerting tension on the actin network and/or pressure on the cytoskeleton elements lining the plasma membrane. The chain of events that follows remains to be further analysed but includes transient pH changes in the cytosol and sustained pH changes in the cell wall. Transduction ends with relocation of the auxin efflux carriers responsible for the lateral transport of auxin, which reorients the root tip in the direction of gravity. Many questions remain to be solved but recent studies now herald a better understanding of the molecular events involved in gravisensing.