Arabidopsis thaliana is a plant that is emerging as a model for understanding plant genetics, development and physiology at the molecular level. It has many characteristics that make it more amenable to molecular inquiry than are other flowering plants and yet because it is a flowering plant, has many homologous DNA sequences and genes which can be used to both isolate and understand gene action in plants with less accessible genomes. The laboratory headed by Dr. Gerald Fink has been in the forefront of those using Arabidopsis to ask questions which have been unanswerable in previous work with plants. The biosynthetic pathway for aromatic amino acids is under study and that study has already provided information suggesting that differences exist between the pathway in animals and plants. Continuation of this work requires more appropriate facilities for growing plants under controlled conditions. The greenhouse, which will be built on the roof of the Whitehead Biomedical Institute, will allow the continuation and expansion of research using plants as experimental organisms by scientists in Dr. Fink's laboratory as well as others at the Institute.***//