Significance

In pollen grains, the known function of the vegetative cell is to extend a pollen tube to transport the two sperm cells to the embryo sac for fertilization. Because the vegetative cell is much larger and more metabolically active than sperm, it has been assumed that the vegetative cell also might supply various components to sperm, but there was no direct evidence to support this hypothesis. We used deletion and promoter exchange constructs to provide direct evidence that the vegetative cell provides protein-encoding transcripts to sperm cells, highlighting a previously unidentified role of the vegetative cell.