How do plant roots sense and respond to gravity?





Changes in cytoplasmic calcium levels are thought to be part of the signal transduction/sensory mechanism whereby roots respond to gravity. This plant has been loaded with a fluorescent dye that reports cytoplasmic calcium levels. The root was then imaged using confocal microscopy to generate a map of the calcium response of the root as it is stimulated by a change in gravity. The top image is a 'normal' microscope image of the root, the lower image is the confocal/computer generated image of the calcium dynamics. Because of its small size, optical accessibility and the range of molecular tools available we are using Arabidopsis thaliana as the plant for these studies.

We are currently applying this sort of technology to try and determine the role of calcium, pH and other regulatory molecules in transducing the gravity signal in roots. The main workers on this project are: