RRC ID 36741
Author Toda E, Ohnishi Y, Okamoto T.
Title Development of Polyspermic Rice Zygotes.
Journal Plant Physiol
Abstract Fertilization is a general feature of eukaryotic uni- and multicellular organisms to restore a diploid genome from female and male gamete haploid genomes. In most animals and fucoid algae, polyspermy block occurs at the plasmogamy step. Because the polyspermy barrier in animals and in fucoid algae is incomplete, polyspermic zygotes are generated by multiple fertilization events. However, these polyspermic zygotes with extra centrioles from multiple sperms show aberrant nuclear and cell division. In angiosperms, polyspermy block functions in the egg cell and the central cell to promote faithful double fertilization, although the mechanism of polyspermy block remains unclear. In contrast to the case in animals and fucoid algae, polyspermic zygotes formed in angiosperms are not expected to die because angiosperms lack centrosomes. However, there have been no reports on the developmental profiles of polyspermic zygotes at cellular level in angiosperms. In this study, we produced polyspermic rice zygotes by electric fusion of an egg cell with two sperm cells, and monitored their developmental profiles. Two sperm nuclei and an egg nucleus fused into a zygotic nucleus, and the triploid zygote divided into a two-celled embryo via mitotic division with a typical bipolar microtubule spindle, as observed during mitosis of a diploid zygote. The two-celled proembryos further developed and regenerated into triploid plants. These findings suggest that polyspermic plant zygotes have the potential to form triploid embryos. Polyspermy in angiosperms might be a pathway for the formation of triploid plants, which can contribute significantly to the formation of autopolyploids.
Volume 171(1)
Pages 206-14
Published 2016-5-1
DOI 10.1104/pp.15.01953
PII pp.15.01953
PMID 26945052
PMC PMC4854695
MeSH Cell Division Cell Fusion / methods Cell Nucleus / metabolism Cell Nucleus Division / physiology Chromatin / metabolism Diploidy Fertilization / physiology* Flow Cytometry Microtubules / metabolism Mitosis Oryza / cytology* Oryza / embryology* Oryza / genetics* Oryza / physiology Seeds / embryology Triploidy Zygote / cytology* Zygote / growth & development* Zygote / physiology
IF 6.902
Times Cited 12
Arabidopsis / Cultured plant cells, genes rpc00031