As the site of photosynthesis, the chloroplast is the defining organelle of green plants and may be thought of as the world's life-support system. It is an attractive target for functional genomics because it participates in a wide array of biosynthetic processes yet has a similar number of genes and metabolic processes as a bacterial cell. The aim of this project is to determine functions for the ~4,400 nuclear genes predicted to encode plastid-targeted proteins in Arabidopsis. Computer methods are being used to create structural models for many plastid proteins and sequenced bacterial genomes are being analyzed to link genes of unknown function with those of known function. Together, these informatics approaches will generate hypotheses for the roles of genes of unknown function. Knockout lines will be analyzed for chloroplast, plant, and seed morphology, as well as photosynthetic parameters and selected chloroplast-synthesized metabolites. In-depth characterization of mutants with morphological or metabolic phenotypes will be performed, including analyzing flux through the central metabolic network in seeds. The informatic and phenotypic data will be made available to the research community through a project website (http://plastid.msu.edu ).
Broader Impacts: By enriching the annotation of nuclear genes encoding plastid-targeted proteins, the research will lay the foundation for a comprehensive understanding of plastid function throughout the life cycle of plants. The project will contribute to the objectives of the 2010 Project by attempting to improve the annotation of approximately 15% of the protein-coding genes of Arabidopsis. Because a number of the traits that will be studied are important targets in crops, these results should inform approaches to transgenic crop improvement and molecular breeding of economically important plants.
The project will involve interdisciplinary training of students and postdoctoral researchers. Each trainee will be exposed to multiple areas of science, ranging from informatic approaches, through high-throughput phenotypic analysis and flux measurements, to data analysis methods, preparing them for 21st century biology careers. In addition to cross-training of students, this project will integrate research and education at three levels: 1.Summer research experiences for undergraduate students and secondary school teachers; 2.Summer research opportunities for faculty from primarily undergraduate schools; 3.Training of participants in cutting edge computer-based curriculum development tools using the Lon-CAPA web-based course management system (www.lon-capa.org).
