TY  - JOUR
A1  - Batista, Rita A.
A1  - Moreno-Romero, Jordi
A1  - Qiu, Yichun
A1  - van Boven, Joram
A1  - Santos-Gonzalez, Juan
A1  - Figueiredo, Duarte Dionisio
A1  - Köhler, Claudia
T1  - The MADS-box transcription factor PHERES1 controls imprinting in the endosperm by binding to domesticated transposons
JF  - eLife
N2  - MADS-box transcription factors (TFs) are ubiquitous in eukaryotic organisms and play major roles during plant development. Nevertheless, their function in seed development remains largely unknown. Here, we show that the imprinted Arabidopsis thaliana MADS-box TF PHERES1 (PHE1) is a master regulator of paternally expressed imprinted genes, as well as of non-imprinted key regulators of endosperm development. PHE1 binding sites show distinct epigenetic modifications on maternal and paternal alleles, correlating with parental-specific transcriptional activity. Importantly, we show that the CArG-box-like DNA-binding motifs that are bound by PHE1 have been distributed by RC/Helitron transposable elements. Our data provide an example of the molecular domestication of these elements which, by distributing PHE1 binding sites throughout the genome, have facilitated the recruitment of crucial endosperm regulators into a single transcriptional network.
Y1  - 2019
U6  - https://doi.org/10.7554/eLife.50541
SN  - 2050-084X
VL  - 8
PB  - eLife Sciences Publications
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Batista, Rita A.
A1  - Figueiredo, Duarte Dionisio
A1  - Santos-Gonzalez, Juan
A1  - Köhler, Claudia
T1  - Auxin regulates endosperm cellularization in Arabidopsis
JF  - Genes & Development
N2  - 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.
KW  - auxin
KW  - cellularization
KW  - endosperm
KW  - hybridization barrier
KW  - seed development
KW  - triploid block
Y1  - 2019
U6  - https://doi.org/10.1101/gad.316554.118
SN  - 0890-9369
SN  - 1549-5477
VL  - 33
IS  - 7-8
SP  - 466
EP  - 476
PB  - Cold Spring Harbor Laboratory Press
CY  - Cold Spring Harbor, NY
ER  -