Figure 7
Seasonal changes of GS gene expression in poplar trees. Total RNA was extracted from leaves, stem, buds and bark of 10-year-old hybrid poplar trees. Transcript levels of PtGS1.1, PtGS1.2, PtGS1.3 and PtGS2 were determined by real-time qPCR analysis as described. Expression levels are presented as relative values to reference genes (actin2 and ubiquitin). The histograms represent the mean values of at least three independent experiments with standard deviations.