An initial conceptual framework
now exists for describing how whole-plant processes such as source-sink
relationships and sink strength are influenced, and indeed regulated, at the
genetic level. Based on this hypothesis, we are leveraging the Populus genome
to discover genes important to the process of carbon sequestration in plants
and soils. We are focusing on the identification of genes that control points
for the flow and anabolic transformations of carbon in roots, concentrating on
genes that favor increased sink activity and synthesis of chemical forms that
favor slow turnover rates of soil organic matter. Our key approaches are de
novo gene discovery, comparative and functional genomics, transgenesis,
high-throughput metabolic phenotyping, and tissue-specific expression
profiling. We seek to enhance carbon allocation (i.e., the movement of carbon
into sink tissues) and partitioning (i.e., the deposition of carbon in various
chemical forms) to roots by altering the auxin and cytokinin signaling
pathways. We are also undertaking two major gene discovery efforts aimed at
identifying novel genes that control carbon allocation and partitioning in
Populus. This broad, integrated approach is aimed at ultimately enhancing root
biomass as well as longevity, thus providing the best prospects for significant
enhancement of belowground carbon storage.
The objectives of this project
are to:
- Identify candidate genes with putative
roles in belowground carbon allocation and partitioning.
- Explore the functions of candidate genes
using Populus transformation, focusing on a variety of transgenic approaches
for characterizing putative carbon allocation and partitioning gene function.
- Evaluate effects of candidate genes and
implications for carbon sequestration using a combination of high-throughput
whole-plant physiological measurements, GC/MS-based metabolic profiling, and
microarray-based expression profiling.
This
research will be conducted as a collaborative project by scientists at Oak
Ridge National Laboratory, University of Florida, Oregon State University,
United States Forest Service, University of Minnesota and the University of
Tennessee. of Tennessee. |
