Ion transporters involved in pollen germination and pollen tube tip-growth.

Pollen germination (PG) and pollen tube growth (PTG) play crucial roles in sexual reproduction of flowering plants by sending sperm cells to the ovule. These two processes are regarded as ideal model system for the study of cell signaling and cell polarized growth. It has been considered for a long time that ion transports across the pollen tube membranes are essential for pollen tube navigation and growth. Previous transcriptome analyses for Arabidopsis have shown that the transcripts related to cellular transport are correspondingly overrepresented during the process of pollen tube growth. Here, we showed that 459 transporter genes expressed during PG and PTG in Arabidopsis. In addition, the gene expression profiles of ion (including Ca(2+), H(+), K(+), Cl(-)) channels and transporters were further analyzed. This analysis provides novel information for the potential candidate genes involving in ion fluxes across the pollen tube membranes and in regulation of pollen tube tip growth.