Knowledge Bank

Pollen grains, the male reproductive structures of flowering plants, are shielded by a resilient cell wall structure called exine. Apertures are areas on the pollen surface that receive limited or no exine deposition. Their patterns vary from species to species, and they play crucial roles in pollen tube emergence during pollen germination, and in hydration of the pollen grain. In Arabidopsis thaliana, three equidistant apertures form during the tetrad stage of pollen development, when future aperture sites are created in sister microspores through delivery of specific proteins and lipids to the three equidistant domains of the plasma membrane. INP1 and INP2 are the previously characterized aperture factors that are essential for aperture formation in Arabidopsis pollen and appear to be species-specific interacting partners. In this study, we investigated the interactions between INP1, INP2, and two recently discovered pollen aperture factors. Our findings will enhance the understanding of how specific domains of the plasma membrane are created in the development of pollen apertures, with broader implications for plant reproduction and development.