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Fertilization and embryogenesis in plants

Martin Bayer

Martin Bayer

  • PhD at the University of Hohenheim, Stuttgart, 2000-04
  • Postdoctoral training at the Cold Spring Harbor Laboratory, NY, 2004-08
  • Postdoctoral training at the University of Zürich, 2008-09
  • Project leader at the MPI since 2009

Research Interest

Multi-cellular organisms rely on a robust network of temporal and spatial coordinates during their development from a single cell. Different organisms have evolved different strategies to obtain such information from internal or external cues.

Little is known about such signals during early embryogenesis of higher plants. In Arabidopsis thaliana, the first asymmetric division marks a crucial cell-fate decision between embryonic development of the apical daughter cell and mostly extra-embryonic suspensor formation of the basal cell. The plant hormone auxin plays a crucial role in establishing and maintaining the polarity of the embryo proper. It is currently not known, however, how polarity is established in the zygote. It is possible that asymmetrically deposited cues in the egg cell determine the apical-basal axis of the zygote. Alternatively, the sperm may provide polarity signals as it does in many other organisms.

Recently we described a sperm-specific cytoplasmic kinase gene that controls the elongation of the zygote and suspensor formation after fertilization (Bayer et al., 2009). This example demonstrates that sperm-derived factors can play a crucial role in early cell fate decisions in plants.

In our research group we are currently using the model organism Arabidopsis thaliana to study sperm-derived signals that guide early embryonic patterning in plants.

Selected Reading

1) Babu Y, Musielak TJ, Henschen A, Bayer M (2013) Suspensor length determines developmental progression of the embryo in Arabidopsis thaliana. Plant Physiol 10.1104/pp.113.217166
 
2) Bayer M, Nawy, T, Giglione C, Galli M, Meinnel T, et al. (2009) Paternal control of embryonic patterning in Arabidopsis thaliana. Science 323, 1485-8.
 
3) Nawy T, Lukowitz W & Bayer M (2008) Talk global, act local – patterning the Arabidopsis embryo. Curr Opin Plant Biol 11, 28-33.
(click to enlarge)
Left panel: Sperm cell-specific GFP expression in mature Arabidopsis pollen; center panel: Immature seed with GFP reporter expression in nuclei of endosperm and zygote; right panel: 8-cell stage embryo, the arrow head marks the boundary between proem-bryo and suspensor. Confocal laser scanning micrographs (DAPI: blue, PI: red, and GFP: green) with DIC overlay; scale bars 20µm.