Fig. 8

Principal component analysis and cluster of genes differentially expressed. PCA of 24 Vitis vinifera defense-related gene expression data sets for visualizing observations in a 2-dimensional space in order to identify uniform or atypical groups of observations. a Projection on the standard unit circle of the quantitative variables (genes): b The two major principal components explaining ~ 60% of the expression variance plotted for 18 samples. Gene expression data were obtained by microfluidic dynamic array (squared plot) or by the Stratagene Mx3005P system (triangular plot). The different groups are indicated by different colors (blue: control untreated; black: BTH-treated; and green: FOS-treated)