Transcriptome-wide analysis of apical shoot development during growing season in Pinus canariensis

The shoot apical meristem is responsible of seasonal length increase in plants. In woody plants transition from primary to secondary growth is also produced during seasonal apical growth. These processes are controlled by different families of transcription factors. Using a previously constructed Pinus canariensis transcriptome, we designed a genomic microarray to measure the levels of transcription during apical growth. The identification of differentially expressed genes was performed by mean of a time-course analysis. mRNA samples were collected at 5 dates during the growing season in Pinus canariensis, supported by microscopical observation of developmental activity: April 15th, April 30th, May 22nd, July 3rd and September 11th. Three biological replicates were collected for each time sampled, and therefore 15 mRNA samples were hybridazed in a one-color microarray experiment.