An Orphaned Kinesin with a Leading Role in Plant Cell Morphogenesis

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).

During plant development, plant cells undergo a highly orchestrated series of cell divisions and elongation events that contribute directly to the shape of the adult plant. Central to both cell division and elongation are microtubules, which are subcellular elements that act as guides and transport rails. Kinesins are a class of cellular motors that interact with microtubules and serve to assist in both transport of cellular components and to affect the function and configuration of microtubules themselves. Evolutionary forces have acted upon the ancestral kinesin motor in diverse ways, to the extent that 15 subfamilies are now recognized throughout all eukaryotic cells. The research to be carried out will investigate how one kinesin, termed ATKINUA, acts during plant development to affect growth and development. Genetic evidence indicates ATKINUA is absolutely required for early development in the most basal of all organs, the shoot apical meristem (which houses the cells that give rise to all aerial portions of the plant), and in more derived tissues and cells, including leaf stomata (which are involved in gas exchange and water regulation). Experiments will be carried out to isolate and characterize plants that do not express this protein normally, and this will provide insight into how it usually functions. Additional experiments will be carried out using transgenic plants in which a fluorescent protein is engineered into ATKINUA; this will enable the researchers to visualize this kinesin in living cells during development. Because this kinesin shows preferential association with the microtubule array that assists in determining the plane of cell division, the researchers will engineer mutations into the kinesin that predictably should disrupt this localization; the effects of this mis-targeted kinesin will be studied in transgenic plants. Bioinformatic analysis of this kinesin indicates it has the potential to interact with signaling moieties in the cell. Therefore, a series of experiments will be carried out to identify its interacting proteins; the researchers anticipate the identification of these interacting proteins will lead to further experiments aimed at understanding how plant cells integrate the activity of this kinesin to affect normal plant growth and development.

Broader Impacts

Plants comprise the foundation for all agricultural activities, so understanding the basic mechanisms that facilitate their normal development is critical if researchers are to pursue a strategic effort in improving crops. This project seeks to provide information that will contribute to such a strategic effort. The project will also provide training for two critical groups of young scientists. First, a postdoctoral researcher will be trained in modern cell biological methods, which will enable the person to establish and carry out future research that is critical for the country's scientific vitality. In addition, this person will receive training in classroom instruction, which will enhance his or her teaching effectiveness in a future academic position. Second, undergraduate students who are enrolled in a sophomore-level cell and molecular biology course will benefit from this project. These students will participate in the experiments to identify interacting proteins of ATKINUA. The anticipated outcome of this experience will be an excitement for scientific research. Opportunities will be provided, after the class is completed, for interested students to continue with the research. Possibly, through this experience, one or more students will decide to choose a career path in science.