Expression data from BIG LEAF

We study differences in gene expression between Populus P35S::BL (BL-oe) lines and control, affecting plant growth and differentiation, and dormancy. We used microarrays to detail the global program of gene expression underlying morphological and developmental changes droved by overexpression of BL gene. We identified an activation tagging mutant with increased leaf size and correspondingly name it BIG LEAF (BL). We positioned the tag, localized a putative candidate gene and verified transcription activation. The activated gene encodes a WD40 putative transcription regulator similar to the Arabidopsis thaliana STERILE APETALA (SAP). We recapitulated the phenotype by overexpression of the gene into the same genotype under strong constitutive promoter (P35S::BL, BL-oe). Transgenic up-regulation of the BL gene caused enhanced leaf size, early bud-break, and suppression of secondary growth. BL transcript abundance in wild type plants is in apical tissues, mostly in shoot meristem, leaf primordia and axillary meristem. Our data indicates that BL plays an important role in the process of tree growth. Poplar apex, secondary stem (30th internode), and leaves (at 30 node) was selected for RNA extraction and hybridization on Affymetrix microarrays. We sought to obtain expression of affected genes in P35S::BL lines and control wild type (WT-717), in order to increase the resolution of expression profiles inducing the developmental changes in P35S::BL. To do that, we selected apex, stem and leaf tissue from greenhouse healthy plants.