C3/C4 DB  

Search/Browse DB |  Project Resources |  Project Summary |  Home page

Project Summary

The C4 complex of traits, which includes C4-type carbon fixation shared between leaf bundle sheath (BS) and mesophyll (M) cells, high venation density, high plasmodesmatal density at the BS/M interface, and development of a highly photosynthetic and gas-impermeable BS, has evolved independently at least 50 times from C3-type ancestral species, with particular frequency among the grasses. The objectives of this project are (1) to compare the patterns of transcripts, proteins, metabolic activities and anatomical features at discrete stages and in specific cell types in the C3 grass rice and the C4 grasses maize and sorghum, and (2) from these datasets, to interpret cellular and subcellular metabolic differentiation, and to develop a model of the regulatory networks that govern C4 anatomical and physiological traits, to provide a rationale for enhancing C3 crops with advantageous C4 traits. To achieve these goals, the team will first calibrate leaf developmental gradients by documenting the coincident anatomical and physiological features that define each stage with precision. Second, defined stages from these calibrated source materials will be subjected to transcript profiling, comparative proteome analysis, metabolite analysis, and photosynthetic and vascular activity assays. We will develop novel methods for transcriptome and proteome analysis using laser microdissection techniques, and for BS and M cells and vascular strands in particular. These datasets will be linked through the development of new informatics tools that will enable rigorous comparative transcriptional and proteome analysis. We will generate a relational database (C3/C4 DB) that will enable researchers to query our combined datasets to identify genes and proteins associated with specific developmental phases, cell types and tissue types associated with C4 traits. The source materials for these public datasets will be sufficiently calibrated and cross-referenced to permit the addition of community data on the same cellular gradient framework. This will provide a foundation for a systems biology approach to understanding C4 biology.

copy right statement