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Research article - Peer-reviewed, 2019

Auxin regulates endosperm cellularization in Arabidopsis

Batista, Rita A.; Figueiredo, Duarte D.; Santos-Gonzalez, Juan; Konder, Claudia

Abstract

The endosperm is an ephemeral tissue that nourishes the developing embryo, similar to the placenta in mammals. In most angiosperms, endosperm development starts as a syncytium, in which nuclear divisions are not followed by cytokinesis. The timing of endosperm cellularization largely varies between species, and the event triggering this transition remains unknown. Here we show that increased auxin biosynthesis in the endosperm prevents its cellularization, leading to seed arrest. Auxin-overproducing seeds phenocopy paternal-excess triploid seeds derived from hybridizations of diploid maternal plants with tetraploid fathers. Concurrently, auxin-related genes are strongly overexpressed in triploid seeds, correlating with increased auxin activity. Reducing auxin biosynthesis and signaling reestablishes endosperm cellularization in triploid seeds and restores their viability, highlighting a causal role of increased auxin in preventing endosperm cellularization. We propose that auxin determines the time of endosperm cellularization, and thereby uncovered a central role of auxin in establishing hybridization barriers in plants.

Keywords

auxin; cellularization; endosperm; hybridization barrier; seed development; triploid block

Published in

Genes and Development
2019, volume: 33, number: 7-8, pages: 466-476
Publisher: COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT

Authors' information

Swedish University of Agricultural Sciences, Department of Plant Biology
Figueiredo, Duarte
Swedish University of Agricultural Sciences, Department of Plant Biology
Swedish University of Agricultural Sciences, Department of Plant Biology
Swedish University of Agricultural Sciences, Department of Plant Biology

UKÄ Subject classification

Developmental Biology

Publication Identifiers

DOI: https://doi.org/10.1101/gad.316554.118

URI (permanent link to this page)

https://res.slu.se/id/publ/99563