Figure 1.

Microarray data for putative exocyst components in Arabidopsis indicate that transcripts for all eight subunits are expressed widely. In particular, the experiments of Honys and Twell (2004) show that AtSEC8, as well as other putative exocyst components, are expressed in developing pollen. Pollen sources of RNA for the expression analysis included uninucleate microspores (UNM), bicellular pollen (BCP), immature tricellular pollen (TCP), and mature pollen grains (MPG). Additional sources of RNA for the analysis included cotyledons (COT), leaves (LEF), petioles (PET), stems (STM), roots (ROT), root hairs (RHR), and cell suspensions (SUS). White (no expression) indicates that expression was not consistently detected among replicates. For brevity, the data shown for AtEXO70 represent only three of the 23 homologs of this exocyst component in Arabidopsis; these are the homologs highly expressed in the pollen. Nomenclature is based upon that of Elias et al. (2003).