Abstract:

The polar growth of pollen tubes is essential for the delivery of sperm cells during fertilization in angiosperms. How this polar growth is regulated has been a long‐standing question. An in vitro pharmacological assay previously implicated proton flux in pollen tube growth, although genetic and cellular supporting evidence was lacking. Here, we report that protons form a gradient from the pollen tube tip to the shank region and this gradient is generated by three members of Arabidopsis H⁺‐ATPases (AHAs). Genetic analysis suggested that these AHAs are essential for pollen tube growth, thus providing new insight into the regulation of polar growth.