Plant & Animal Genome IX Conference

Workshop: Forest Tree Genome Mapping
W26_05.html

MOLECULAR PORTRAITS OF NITROGEN RESPONSES IN POPLARS

School of Forest Resources and Conservation, and Plant Molecular and Cellular Biology Program, University of Florida, P.O. Box 110410, Gainesville FL 32611 USA

Nitrogen fertilization induces dramatic changes in the growth and development of plants. These changes are mediated at the cellular level in part by N-responsive genes. We have set out to develop a molecular phenotype of N-modulated responses in poplar trees that are induced prior to or concomitant with visible changes in growth resulting from varying levels of N availability. We used differential display of mRNA to identify cDNAs whose expression patterns are altered in response to limiting versus luxuriant levels of N fertilization. Membrane-based arrays were then used to quantify the expression levels of these cDNAs. Analysis of these arrays has allowed us to construct a spatial expression map of these N-responsive cDNAs within different tissues of the tree. These cDNAs represent a diverse array of biochemical and cellular processes that are modulated in response to N availability , and thus are useful sentinels for monitoring global responses to changing N status.