ABSTRACT
Recent work has revealed signaling molecules that control pollination, including small peptides that mediate pollen recognition and glycoproteins that support pollen tube growth. The polarized growth of pollen tubes requires a calcium-mediated signal cascade, and cues derived from the haploid and diploid ovule cells guide pollen tubes to the eggs.
Subject(s)
Plant Physiological Phenomena , Pollen , Cell Polarity , Fertilization , Plant Cells , Plants/embryology , SeedsABSTRACT
In flowering plants, a series of cell-cell interactions govern the delivery of sperm to the ovules through precise guidance of pollen tubes. Two Arabidopsis genes, POP2 and POP3, were found that mediate pollen tube guidance and are critical for self-fertility in diploid reproductive cells. The pop2 and pop3 mutations exhibited genetic redundancy: Self-sterility occurred only when male and female tissues were defective in both genes. This phenotype resembles that found in many self-incompatible species.
