Table 1.
Distributions of six functional-group pollen-preferential transcripts in the five clusters.
| Categories/sub-categories | c0 | c1 | c2 | c3 | c4 | Total |
|---|---|---|---|---|---|---|
| 01 Trancription factor | 176 | 282 | 133 | 89 | 92 | 772 |
| 01.01 ABI3VP1 | 4 | 8 | 6 | 4 | 2 | 24 |
| 01.02 Alfin-like | 1 | 1 | 0 | 2 | 1 | 5 |
| 01.03 AP2-EREBP | 18 | 25 | 11 | 4 | 5 | 63 |
| 01.04 ARF | 1 | 1 | 2 | 1 | 3 | 8 |
| 01.05 ARID | 1 | 1 | 0 | 0 | 0 | 2 |
| 01.06 ARR-B | 0 | 1 | 0 | 0 | 0 | 1 |
| 01.07 BES1 | 0 | 2 | 1 | 0 | 0 | 3 |
| 01.08 bHLH | 11 | 23 | 10 | 5 | 2 | 51 |
| 01.09 bZIP | 9 | 9 | 5 | 2 | 0 | 25 |
| 01.10 C2C2-CO-like | 1 | 0 | 0 | 0 | 1 | 2 |
| 01.11 C2C2-Dof | 5 | 7 | 0 | 0 | 0 | 12 |
| 01.12 C2C2-GATA | 2 | 5 | 0 | 1 | 2 | 10 |
| 01.13 C2C2-YABBY | 1 | 1 | 0 | 1 | 0 | 3 |
| 01.14 C2H2 | 12 | 18 | 9 | 6 | 9 | 54 |
| 01.15 C3 H | 4 | 11 | 1 | 2 | 9 | 27 |
| 01.16 C3HC4 | 1 | 0 | 1 | 3 | 1 | 6 |
| 01.17 CCAAT_HAP2 | 0 | 2 | 1 | 0 | 0 | 3 |
| 01.18 CCAAT_HAP3 | 1 | 4 | 0 | 1 | 0 | 6 |
| 01.19 CCAAT_HAP5 | 2 | 2 | 0 | 3 | 2 | 9 |
| 01.20 CPP | 1 | 2 | 1 | 0 | 1 | 5 |
| 01.21 CSD | 0 | 0 | 0 | 0 | 1 | 1 |
| 01.22 DBP | 0 | 3 | 0 | 1 | 0 | 4 |
| 01.23 DDT | 3 | 0 | 3 | 0 | 1 | 7 |
| 01.24 G2-like | 3 | 3 | 2 | 1 | 2 | 11 |
| 01.25 GeBP | 1 | 0 | 0 | 1 | 0 | 2 |
| 01.26 GRAS | 6 | 6 | 6 | 2 | 0 | 20 |
| 01.27 GRF | 0 | 1 | 0 | 0 | 0 | 1 |
| 01.28 HB | 7 | 15 | 5 | 5 | 0 | 32 |
| 01.29 HMG | 0 | 1 | 1 | 0 | 2 | 4 |
| 01.30 HRT | 0 | 1 | 0 | 0 | 0 | 1 |
| 01.31 HSF | 2 | 1 | 1 | 1 | 1 | 6 |
| 01.32 Jumonji | 3 | 2 | 1 | 2 | 0 | 8 |
| 01.33 LFY | 0 | 1 | 0 | 0 | 0 | 1 |
| 01.34 LIM | 0 | 3 | 0 | 0 | 0 | 3 |
| 01.35 LUG | 0 | 0 | 1 | 0 | 0 | 1 |
| 01.36 MADS | 10 | 13 | 8 | 5 | 8 | 44 |
| 01.37 MYB and MYB-related | 20 | 26 | 18 | 7 | 12 | 83 |
| 01.38 NAC | 9 | 26 | 8 | 2 | 6 | 51 |
| 01.39 Orphans | 14 | 17 | 10 | 2 | 2 | 45 |
| 01.40 PHD | 4 | 5 | 3 | 4 | 2 | 18 |
| 01.41 PLATZ | 1 | 0 | 1 | 1 | 0 | 3 |
| 01.42 Pseudo ARR-B | 0 | 1 | 0 | 0 | 0 | 1 |
| 01.43 PWP-RK | 1 | 4 | 0 | 0 | 0 | 5 |
| 01.44 SBP | 1 | 1 | 2 | 0 | 0 | 4 |
| 01.45 SET | 3 | 2 | 2 | 6 | 7 | 20 |
| 01.46 S1Fa-like | 0 | 0 | 0 | 2 | 0 | 2 |
| 01.47 SNF2 | 4 | 3 | 2 | 3 | 6 | 18 |
| 01.48 TAZ | 0 | 0 | 0 | 0 | 1 | 1 |
| 01.49 TCP | 3 | 3 | 2 | 0 | 2 | 10 |
| 01.50 Trihelix | 0 | 4 | 1 | 0 | 0 | 5 |
| 01.51 TUB | 1 | 1 | 1 | 3 | 0 | 6 |
| 01.52 ULT | 0 | 0 | 1 | 1 | 0 | 2 |
| 01.53 WRKY | 3 | 9 | 3 | 4 | 1 | 20 |
| 01.54 zf-HD | 2 | 3 | 2 | 0 | 0 | 7 |
| 01.55 ZIM | 0 | 4 | 1 | 1 | 0 | 6 |
| 02 Phytohormone | 31 | 52 | 28 | 25 | 10 | 146 |
| 02.01 Auxin | 13 | 31 | 16 | 13 | 7 | 80 |
| 02.02 BR | 3 | 2 | 2 | 2 | 1 | 10 |
| 02.03 Cytokinin | 2 | 3 | 3 | 0 | 0 | 8 |
| 02.04 Ethylene | 6 | 13 | 3 | 3 | 2 | 27 |
| 02.05 GA | 3 | 2 | 0 | 6 | 0 | 11 |
| 02.06 JA | 4 | 1 | 4 | 1 | 0 | 10 |
| 03 Cell cycle | 36 | 63 | 30 | 25 | 43 | 197 |
| 04 Kinase | 110 | 319 | 116 | 78 | 43 | 666 |
| 04.01 Calcium | 4 | 19 | 2 | 6 | 2 | 33 |
| 04.02 Inositol phosphate | 6 | 21 | 7 | 5 | 0 | 39 |
| 04.03 MAPK | 1 | 11 | 1 | 3 | 0 | 16 |
| 04.04 Pto-pti | 1 | 5 | 0 | 1 | 0 | 7 |
| 04.05 Receptor kinase | 46 | 83 | 43 | 20 | 5 | 197 |
| 04.06 WAK | 10 | 14 | 10 | 1 | 2 | 37 |
| 04.07 Others | 42 | 166 | 53 | 42 | 34 | 337 |
| 05 Defense/stress response | 107 | 172 | 109 | 51 | 35 | 474 |
| 06 UPS | 107 | 155 | 100 | 65 | 176 | 603 |
| 06.01 F-box | 75 | 103 | 71 | 49 | 108 | 406 |
| 06.02 Others | 32 | 52 | 29 | 16 | 68 | 197 |
The six functional groups involve transcription factors, phytohormones, cell cycle regulators, defence/stress responders, kinases and ubiquitin/26 S proteasome factors in different expression patterns (shown in Figure 5). Raw data for the clusters are in Additional file 7.