Comparison of the mature pollen proteome with the proteomes of other Arabidopsis thaliana tissues. (A) Cluster dendrogram (Ward method) using the Jaccard-based distance as a measure of dissimilarity between protein lists. The clustering implies that pollen is quite dissimilar with respect to the other tissues; the most similar tissue is “seed.” (B) Proteins of mature pollen are preferentially stable proteins. The distributions of protein instability parameter values of several data sets are shown: 29,988 distinct TAIR7 protein sequences (black line), unambiguously identified proteins by Baerenfaller et al. (2008) (12,043; blue line), and unambiguously identified protein sequences in mature pollen (classes 1a, 1b, 3a; 3141 proteins; red line). (C) Amino acid frequency analysis of all mature pollen proteins versus all distinct proteins in TAIR7. The normalized frequency of the amino acids for both data sets is shown on the left (light red, mature pollen; light blue, TAIR7), and the relative difference on the right. (Blue) Amino acids occurring at a lower relative frequency in the pollen proteome; (red) amino acids with higher relative frequency.
