This award supports the acquisition of eight plant growth chambers and computerized monitoring system that will provide the foundation of a new multi-user plant growth facility in the Department of Cell Biology and Molecular Genetics at the University of Maryland. The facility will be used by investigators whose work with the model plant Arabidopsis thaliana, but address diverse problems. These include the function of vacuolar ion pumps and ethylene receptors, the control and function of genes encoding gluconases used in cell-wall formation and remodeling, and splicing of messenger RNA. Arabidopsis has been increasingly adopted as the experimental material of choice for studies of basic plant biology because of the knowledge of the complete genomic sequence and the availability of large mutant collections, extensive databases and powerful new molecular genetic tools. These chambers will increase the growth area available to these researchers by 3 to 4-fold, and will provide precise control of day-length, light and temperature, all of which can affect the outcome of experiments intended to increase knowledge of plant development, physiology and genetics.