Figure 5.

Expression patterns analysis of 2,858 pollen-preferential transcripts of six functional groups. The 2,858 transcripts, involving transcription factors, phytohormones, kinases, cell cycle regulators, ubiquitin/26 S proteasome system and defence/stress responders, were distributed in five clusters (c0 to c4). The clusters were created by GeneCluster 2.0; raw data for each cluster are listed in Additional file 7. X-axis denotes the developmental stages from UNM to GPG; y-axis denotes the normalized expression level of the transcripts.