Abstract

The endosperm is a developmental innovation of angiosperms that supports embryo growth and germination. Aside from this essential reproductive function, the endosperm fuels angiosperm evolution by rapidly establishing reproductive barriers between incipient species. Specifically, the endosperm prevents hybridization of newly formed polyploids with their non-polyploid progenitors, a phenomenon termed the triploid block. Furthermore, recently diverged diploid species are frequently reproductively isolated by endosperm-based hybridization barriers. Current genetic approaches have revealed a prominent role for epigenetic processes establishing these barriers. In particular, imprinted genes, which are expressed in a parent-of-origin-specific manner, underpin the interploidy barrier in the model species Arabidopsis. We will discuss the mechanisms establishing hybridization barriers in the endosperm, the driving forces for these barriers and their impact for angiosperm evolution.This article is part of the theme issue 'How does epigenetics influence the course of evolution?'

Keywords

polyploidy; endosperm; hybridization barrier; speciation; genomic imprinting; triploid block

Published in

Philosophical Transactions B: Biological Sciences
2021, volume: 376, number: 1826, article number: 20200118
Publisher: ROYAL SOC

Authors' information