AUTHOR=Caselli Francesca , Beretta Veronica Maria , Mantegazza Otho , Petrella Rosanna , Leo Giulia , Guazzotti Andrea , Herrera-Ubaldo Humberto , de Folter Stefan , Mendes Marta Adelina , Kater Martin M. , Gregis Veronica 

TITLE=REM34 and REM35 Control Female and Male Gametophyte Development in Arabidopsis thaliana

JOURNAL=Frontiers in Plant Science

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.01351

DOI=10.3389/fpls.2019.01351

ISSN=1664-462X

ABSTRACT=<p>The REproductive Meristem (REM) gene family encodes for transcription factors belonging to the B3 DNA binding domain superfamily. In <italic>Arabidopsis thaliana</italic>, the <italic>REM</italic> gene family is composed of 45 members, preferentially expressed during flower, ovule, and seed developments. Only a few members of this family have been functionally characterized: <italic>VERNALIZATION1</italic> (<italic>VRN1</italic>) and, most recently, <italic>TARGET OF FLC AND SVP1</italic> (<italic>TFS1</italic>) regulate flowering time and <italic>VERDANDI</italic> (<italic>VDD</italic>), together with <italic>VALKYRIE</italic> (<italic>VAL</italic>) that control the death of the receptive synergid cell in the female gametophyte. We investigated the role of <italic>REM34</italic>, <italic>REM35</italic>, and <italic>REM36</italic>, three closely related and linked genes similarly expressed in both female and male gametophytes. Simultaneous silencing by RNA interference (RNAi) caused about 50% of the ovules to remain unfertilized. Careful evaluation of both ovule and pollen developments showed that this partial sterility of the transgenic RNAi lines was due to a postmeiotic block in both female and male gametophytes. Furthermore, protein interaction assays revealed that REM34 and REM35 interact, which suggests that they work together during the first stages of gametogenesis.</p>