THE PLANT CELL IN A NUTSHELL
Faculty of Agriculture Department of Plant-bioscience
Research Associate TONOSAKI Kaoru
【Science in genetics and breeding】
Endosperm is a nourishment tissue for embryo development in seed and for seedling growth after germination. Endosperm development is complexly regulated by epigenetic mechanisms such as histone modifications. One of the repressive histone marks, H3K27me3, is mediated by PRC2 (Polycomb repressive complex 2). PRC2 is largely conserved in mammal and plant and be involved in several development processes via repression of gene transcription. In Arabidopsis, PRC2 represses endosperm development before fertilization and after fertilization. However, PRC2 function for endosperm development is still unclear in monocot species.
We wanted to know how PRC2 involves in the endosperm development, and to identify what the direct target genes are in rice.
We found nuclear divisions in the central cell before fertilization in the mutation of EMBRYONIC FLOWER2a (one of the components for PRC2) in rice. The divided nuclei are associate with cytosol, which accumulates starch granules and protein bodies. After fertilization, the mutant also displays delayed developmental transitions in the endosperm. By using ChIP-seq analysis, we identified direct targets of PRC2 in the endosperm. Those include over 100 transcription factor genes and about 200 of paternally expressed imprinted genes.
Identification for Key regulators for repression of central cell nuclear divisions and endosperm developmental transitions require more detailed investigations.
Repressor of Endosperm Formation in Rice
Author(s) and Institutions:
Kaoru Tonosaki and Tetsu Kinoshita
Iwate University and Yokohama City University
rice, endosperm, Polycomb repressive complex 2, H3K27me3