Seminars

Like animals, plants are viviparous: the plant embryo grows inside its mother, is nourished by her, and eventually emerges from her to live independently. We first identified the ZHOUPI (ZOU) gene in Arabidopsis, where it acts in seeds to promote the breakdown of the endosperm, an embryo-surrounding tissue with a role in nourishing the embryo. Curiously, ZOU genes are found in all types of land plant, most of which do not have endosperm or seeds, and they were likely present in the common ancestor of all land plants. We are trying to find out what the ancestral role of ZOU genes was using comparative functional analyses. I’ll present our work using the liverwort Marchantia polymorpha, mostly on the role of the ZOU orthologue in controlling programmed cell death and differentiation of a novel water conducting cell. Recently we uncovered a role for Marchantia ZOU in reproductive development and I’ll describe our progress in testing the hypothesis that ZOU genes evolved in early land plants to promote breakdown of maternal embryo-surrounding tissues, helping the embryo to emerge.