Poster: Late and Moved Abstracts
Abs #
1021: Exploring maturation and flowering in poplar using microarray expression analysis
To identify candidate genes involved in maturation and flowering, we conducted microarray expression studies using two poplar genotypes (Populus trichocarpa x P. deltoides hybrids) represented in continuous age gradients of one to six years. We designed 70-mers for 228 poplar genes and microarray studies were carried out using the microplate-based 96-well BioGridArray platform (GeneXP Biosciences). Included on the array were close homologs of Arabidopsis flowering control genes,109 transcription factors, 42 chromatin modifiers, and 30 signal transduction factors. Floral buds, vegetative buds and shoot tips were collected at different seasonal time points from juvenile and adult trees and from both basal and upper branches of mature trees. Among all floral bud to vegetative bud comparisons, 14 genes showed consistent upregulation in floral buds. Four genes were consistently upregulated in vegetative buds, including homologs of the Arabidopsis flowering time genes SOC1 and AGL24/SVP. For within-tree maturation, 11 genes were consistently upregulated in upper branch shoot tips compared to basal shoot tips, including a homolog of CONSTANS. Interestingly, PMADS12, a poplar gene related to SVP and AGL24, showed consistent upregulation in mature vegetative buds and shoot tips collected at different seasonal time points compared to tissues from juvenile trees . As the assembled and annotated poplar genome sequence will soon be available, microarray analysis will be an increasingly powerful tool for discovery of genes and pathways regulating tree maturation and flowering.
