The mechanisms controlling gene expression in plants were investigated. Specifically, 4 important cereal seed protein genes and 3 differentially regulated genes coding for glutamine synthetase (a key enzyme in the assimilation of nitrogen by plants) from French bean were examined.
The control regions of 4 cereal seed protein genes, 3 differentially expressed glutamine synthetase genes and the T-cyt gene of A tumefaciens were characterized.
Genes related to plant growth and development were isolated from potato, barley, maize and tobacco, including genes that are activated by the plant growth regulating auxins and cytokinins (plant hormones) as well as genes that are developmentally controlled in maize and barley.
Agrobacterium Ri and Ti T-deoxyribonucleic acid (T-DNA) genes were found to give a spectrum of changes in growth and development in transgenic potato, including effects on the development of root systems. The natural Agrobacterium gene transfer system was studied in detail and genes determining host range and efficiency of transfer were characterized. Gene transfer techniques were also developed for rice.