AUTHOR=Di Marzo Maurizio , Roig-Villanova Irma , Zanchetti Eva , Caselli Francesca , Gregis Veronica , Bardetti Paola , Chiara Matteo , Guazzotti Andrea , Caporali Elisabetta , Mendes Marta Adelina , Colombo Lucia , Kater Martin M. 

TITLE=MADS-Box and bHLH Transcription Factors Coordinate Transmitting Tract Development in Arabidopsis thaliana

JOURNAL=Frontiers in Plant Science

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.00526

DOI=10.3389/fpls.2020.00526

ISSN=1664-462X

ABSTRACT=<p>The MADS-domain transcription factor <italic>SEEDSTICK</italic> (<italic>STK</italic>) controls several aspects of plant reproduction. <italic>STK</italic> is co-expressed with <italic>CESTA</italic> (<italic>CES</italic>), a basic Helix-Loop-Helix (bHLH) transcription factor-encoding gene. <italic>CES</italic> was reported to control redundantly with the brassinosteroid positive signaling factors BRASSINOSTEROID ENHANCED EXPRESSION1 (BEE1) and BEE3 the development of the transmitting tract. Combining the <italic>stk ces-4</italic> mutants led to a reduction in ovule fertilization due to a defect in carpel fusion which, caused the formation of holes at the center of the septum where the transmitting tract differentiates. Combining the <italic>stk</italic> mutant with the <italic>bee1 bee3 ces-4</italic> triple mutant showed an increased number of unfertilized ovules and septum defects. The transcriptome profile of this quadruple mutant revealed a small subset of differentially expressed genes which are mainly involved in cell death, extracellular matrix and cell wall development. Our data evidence a regulatory gene network controlling transmitting tract development regulated directly or indirectly by a STK-CES containing complex and reveal new insights in the regulation of transmitting tract development by bHLH and MADS-domain transcription factors.</p>