Abstract: The present invention provides new tools and methods for identifying herbicides and potential herbicides which affect cell plate formation and development. A new protein, phragmoplastin, has been discovered which is associated with cell plate membrane vesicles during cytokinesis. By visualizing the phragmoplastin, one is able to examine the development of the cell plate particularly in response to herbicides or potential herbicides. One method of visualizing phragmoplastin employs immunocytochemical techniques with anti-phragmoplastin antibodies. Another method of visualizing phragmoplastin employs cells which are transformed with a DNA molecule which encodes a chimeric phragmoplastin protein comprised of phragmoplastin and a luminescent tag or protein, fused to the phragmoplastin protein. The phragmoplastin in such cells is visualized by examining the cells under conditions which cause the marker to become visible such as by fluorescent microscopy.

Abstract: The present invention provides new tools and methods for identifying herbicides and potential herbicides which affect cell plate formation and development. A new protein, phragmoplastin, has been discovered which is associated with cell plate membrane vesicles during cytokinesis. By visualizing the phragmoplastin, one is able to examine the development of the cell plate particularly in response to herbicides or potential herbicides. One method of visualizing phragmoplastin employs immunocytochemical techniques with anti-phragmoplastin antibodies. Another method of visualizing phragmoplastin employs cells which are transformed with a DNA molecule which encodes a chimeric phragmoplastin protein comprised of phragmoplastin and a luminescent tag or protein, fused to the phragmoplastin protein. The phragmoplastin in such cells is visualized by examining the cells under conditions which cause the marker to become visible such as by fluorescent microscopy.

Abstract: The invention is directed to the production of plants containing a cDNA clone encoding a bifunctional enzyme, delta.sup.1 -pyrroline-5-carboxylate synthetase, hereinafter P5CS, with both gamma-glutamyl kinase and glutamic-gamma-semialdehyde dehydrogenase activities that catalyzes the first two steps in plant proline production, also called biosynthesis. The invention also provides methods for increasing the salt tolerance and drought resistance of plants, and for increasing the proline production and glutamine synthetase activity in plants.