765 / 2019-06-10 22:02:33

Regulation and function of endosperm cellularization

endosperm cellularization

全体主题 > Development

Seed development in flowering plants is initiated by double fertilization of two female gametes by two sperm cells; fertilization of the haploid egg cell will generate the diploid embryo, while fertilization of the diploid central cell will generate the triploid endosperm. Endosperm development is a complex process; in most flowering plant species free nuclear proliferation without cytokinesis (syncytial phase) is followed by a cellularization phase that is initiated in a region surrounding the embryo and then proceeds from the outer to the inner region of the endosperm. In Arabidopsis, endosperm cellularization coincides with the early heart stage of embryo development. This will allow incoming maternal resources to be directed towards the embryo. Endosperm cellularization failure resulting in seed abortion is a frequently occurring phenomenon in response to interploidy and interspecies hybridization. Consistent with an essential role of endosperm cellularization for triploid embryo survival, several suppressor mutants have been identified that rescues triploid seeds by restoring endosperm cellularization. The objective of this proposal is to address the functional requirement of endosperm cellularization for embryo survival. We aim at distinguishing among the hypotheses that endosperm cellularization is required to (i) remove an inhibitor of embryo growth, (ii) to allow nutrient translocation to the developing embryo.