According to a CNRS communications dated September 4, 2026. Based on a scientific paper published in Science to which the RDP contributed: “An embryo-derived peptide signal directs endosperm polarity.” Thumbnail credit: © Denis DARZACQ/CNRS Images
In flowering plants, seed formation depends on the coordinated development of the embryo and the tissue that surrounds and nourishes it. In a study published in Science, scientists demonstrate, using the model plant Arabidopsis thaliana, that this coordination depends on a genuine molecular dialogue: shortly after fertilization, the embryo produces a small peptide that transmits a signal to neighboring cells and organizes the development of the endosperm. In this way, by controlling its immediate environment, it maximizes its chances of survival.
Double fertilization at the origin of the seed
In flowering plants, or angiosperms, sexual reproduction has a distinctive feature: it relies on double fertilization. When a pollen grain reaches the receptive part of the flower, it germinates and forms a pollen tube that grows toward the ovule. This tube carries two male gametes.
Inside the ovule is a structure consisting of a few cells, called the female gametophyte. It includes, in particular, an egg cell and a central cell. The two male gametes then follow different paths: the first fuses with the egg cell to form the embryo, while the second fuses with the central cell to give rise to the endosperm.
This tissue plays an essential role in seed development. In particular, it facilitates the exchange of nutrients between the tissues of the mother plant and the embryo. Because it serves as an interface between the mother and the embryo, it can be compared, to a certain extent, to the placenta in mammals.
During the first three to four days following fertilization, the endosperm develops rapidly. Its nuclei initially multiply without cell walls forming between them; it then constitutes a large cell containing numerous nuclei, called a coenocyte. Next comes cellularization: cell walls gradually form around the nuclei, separating the cells from one another.
Reference
Audrey Creff et al., An embryo-derived peptide signal directs endosperm polarity in Arabidopsis. Science
DOI:10.1126/science.aed6035