Auxin-dependent patterning and gamete specification in the Arabidopsis female gametophyte.
The female reproductive unit of flowering plants, the haploid female gametophyte, is highly reduced relative to other land plants. We show that patterning of the Arabidopsis female gametophyte depends on an asymmetric distribution of the hormone auxin during its syncitial development. Furthermore, this auxin gradient is correlated with location-specific auxin biosynthesis, rather than auxin efflux that directs patterning in the diploid sporophytic tissues comprising the rest of the plant. Manipulation of auxin responses or synthesis induces switching of gametic and nongametic cell identities and specialized nonreproductive cells to exhibit attributes presumptively lost during angiosperm evolution. These findings may account for the unique egg cell specification characteristic of angiosperms and the formation of seeds with single diploid embryos while containing endosperm that can have variable numbers of parental haploid genomes.
Pagnussat
Gabriela C
GC
Department of Plant Biology, University of California, Davis, CA 95616, USA.
Alandete-Saez
Monica
M
Bowman
John L
JL
Sundaresan
Venkatesan
V
D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D005075:Biological Evolution; D015536:Down-Regulation; D035264:Flowers / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005854:Germ Cells / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D035683:MicroRNAs; D008938:Mitosis; D008954:Models, Biological; D010105:Oxygenases / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012639:Seeds / Q000166:cytology; D015398:Signal Transduction
D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D026901:Membrane Transport Proteins; D035683:MicroRNAs; C116363:PIN1 protein, Arabidopsis; D011993:Recombinant Fusion Proteins; D010105:Oxygenases; C422746:YUC protein, Arabidopsis