RUI: Elucidating and Manipulating the Role of Malate in the Maintenance of Stomatal Aperture

Eastern Michigan University, Ypsilanti MI

Investigators

Abstract

The purpose of Prof. Laporte's research project is to use genetic engineering to alter plant responses to growth under irrigation. Irrigation is widely used to prevent crop losses due to drought. In the United States, approximately 70% of the water diverted by humans is used to irrigate crops. Irrigation has dried up rivers and caused salinization of crop land, which reduces crop productivity. Genetically modified crops that use less water under irrigation conditions have the potential to save massive amounts of irrigation water and to reduce the destruction of farm land. The majority of water used by plants is lost to the atmosphere through openings called stomata on leaf surfaces. Specialized guard cells that border the stomata control stomatal opening and closing through changes in the concentrations of certain ions in the guard cells. Prof. Laporte's research focuses on one of these ions, malate, which is maintained at high concentrations in guard cells when stomata are open. The metabolism of malate is linked to stomatal closure. Prof. Laporte will study the enzyme that metabolizes malate to look for ways of altering its activity, thereby modulating the size of the stomatal opening while maintaining the stomatal function critical to optimal plant growth. The long-term goals of this project include not only a better understanding of the way in which malate metabolism in guard cells regulates the size of the stomatal opening, but also the actual molecular engineering of plants with conservative water use under irrigation. In order to accomplish this, Prof. Laporte will conduct genetic studies of the gene for the malate-metabolizing enzyme, identifying which form of the enzyme is made in guard cells. She will then evaluate the size of the stomatal opening and the use of water in plants that make more the metabolizing enzyme in guard cells than usual, plants that make no metabolizing enzyme in guard cells, and plants that make a mutant metabolizing enzyme in guard cells. These experiments will provide the information Prof. Laporte will use to engineer a plant that uses less irrigation water. Through this research project, Prof. Laporte will also contribute to the training of undergraduate students. Eastern Michigan University has a diverse student body of high-quality undergraduates who are interested in one-on-one training with faculty members. Although many EMU students go on to graduate or professional school or join the scientific workforce; an even larger number become K-12 teachers. While pursuing the goals of this research, Prof. Laporte will train promising undergraduate students, including members of underrepresented minorities, who will become the next generation of scientists and teachers. The extensive connections between EMU and the local K-12 teaching community provide opportunities for high school students, as well as current and future teachers, to learn from and become involved in Prof. Laporte's research program. Many of the molecular, biochemical, and physiological techniques used in this project, along with the accompanying critical thinking skills, can be adapted for use in high school classrooms.