A subunit of the oligosaccharyltransferase complex is required for interspecific gametophyte recognition in Arabidopsis

Lena M Müller, Heike Lindner, Nuno D Pires, Valeria Gagliardini, Ueli Grossniklaus
2016
Species-specific gamete recognition is a key premise to ensure reproductive success and the maintenance of species boundaries. During plant pollen tube (PT) reception, gametophyte interactions likely allow the species-specific recognition of signals from the PT (male gametophyte) by the embryo sac (female gametophyte), resulting in PT rupture, sperm release, and double fertilization. This process is impaired in interspecific crosses between Arabidopsis thaliana and related species, leading to
more » ... ecies, leading to PT overgrowth and a failure to deliver the sperm cells. Here we show that ARTUMES (ARU) specifically regulates the recognition of interspecific PTs in A. thaliana. ARU, identified in a genome-wide association study (GWAS), exclusively influences interspecific-but not intraspecific-gametophyte interactions. ARU encodes the OST3/6 subunit of the oligosaccharyltransferase complex conferring protein N-glycosylation. Our results suggest that glycosylation patterns of cell surface proteins may represent an important mechanism of gametophyte recognition and thus speciation. Species-specific gamete recognition is a key premise to ensure reproductive success and the maintenance of species boundaries. During plant pollen tube (PT) reception, gametophyte interactions likely allow the species-specific recognition of signals from the PT (male gametophyte) by the embryo sac (female gametophyte), resulting in PT rupture, sperm release, and double fertilization. This process is impaired in interspecific crosses between Arabidopsis thaliana and related species, leading to PT overgrowth and a failure to deliver the sperm cells. Here we show that ARTUMES (ARU) specifically regulates the recognition of interspecific PTs in A. thaliana. ARU, identified in a genome-wide association study (GWAS), exclusively influences interspecific-but not intraspecific-gametophyte interactions. ARU encodes the OST3/6 subunit of the oligosaccharyltransferase complex conferring protein N-glycosylation. Our results suggest that glycosylation patterns of cell surface proteins may represent an important mechanism of gametophyte recognition and thus speciation. | www.nature.com/naturecommunications c Pollen donor: A. arenosa Figure 2 | Natural variation in PT reception with different interspecific pollen donors. (a) A subset of A. thaliana accessions pollinated with A. lyrata pollen. Per accession, four to eight siliques were analysed. Box plots are ordered by the mean OG/S value and colour-coded to facilitate comparison with b and c. (b,c) The same subset pollinated with pollen from A. halleri (b) and A. arenosa (c). The accessions show comparable OG/S with all three interspecific pollen donors. NATURE COMMUNICATIONS |
doi:10.5167/uzh-130933 fatcat:gmd4web7o5dsvcttruh3uctbmm