Principal component analysis (PCA) of microarray data and representative K-means profiles of tissue-specific gene expressions. Variance of principal component 1 (PC1) = 41.05% and of principal component 2 (PC2) = 17.73%. Three major regions of dispersion were found representing A) root specific genes (profile 1); B) stem specific genes (profiles 2 and 3) and leaf specific genes (profile 4); and C) seed specific genes (profiles 5, 6 and 7). Genes similarly expressed in different tissues are located in the middle of the PCA figure. R: root; L: leaf; SOV: Shoot outer tissue, vegetative stage; SOGC: shoot outer tissue, green capsule stage; SIV: Shoot inner tissue, vegetative stage; SIGC: shoot inner tissue, green capsule stage; S1: 10-15 days-old seeds; S2: 20-30 days-old seeds; S3: 40-50 days-old seeds.