Although there is compelling evidence supporting a connection between plant hormones and nitrogen (N), the nature of the interaction between these signals has not yet been established. For example, it is not clear whether hormones act as an early or late signal of the change in N status. And it is not clear which of the changes elicited in response to changes in N availability require functional hormone signaling pathways. We are using systems biology approaches that combine genetics, genomics and bioinformatics tools to answer these questions and characterize the mechanisms involved in N:hormones signaling cross-talk. Our current research involves:
- Enhancing and refining our existing qualitative network model of the plant cell to predict mechanisms of regulation and map information flow in gene networks.
- Developing a large scale platform to generate mutants in the selected genes and analyze their phenotypes under various N/hormone conditions.
- Use of whole genome microarray experiments to understand the global consequences of the mutations and refine our models and hypotheses.
Our systems approach should not only help us identify the most important players and increasingly refine our understanding of the mechanisms involved in hormone- and N-signaling pathway interactions, but may also provide insight into the intersection between N and signaling networks activated by other external or internal inputs.