title: Control of inflorescence architecture in tomato by BTB/POZ transcriptional regulators.
abstract: Plant productivity depends on inflorescences, flower-bearing shoots that originate from the stem cell populations of shoot meristems. Inflorescence architecture determines flower production, which can vary dramatically both between and within species. In tomato plants, formation of multiflowered inflorescences depends on a precisely timed process of meristem maturation mediated by the transcription factor gene TERMINATING FLOWER (TMF), but the underlying mechanism is unknown. We show that TMF protein acts together with homologs of the Arabidopsis BLADE-ON-PETIOLE (BOP) transcriptional cofactors, defined by the conserved BTB (Broad complex, Tramtrack, and Bric-a-brac)/POZ (POX virus and zinc finger) domain. TMF and three tomato BOPs (SlBOPs) interact with themselves and each other, and TMF recruits SlBOPs to the nucleus, suggesting formation of a transcriptional complex. Like TMF, SlBOP gene expression is highest during vegetative and transitional stages of meristem maturation, and CRISPR/Cas9 elimination of SlBOP function causes pleiotropic defects, most notably simplification of inflorescences into single flowers, resembling tmf mutants. Flowering defects are enhanced in higher-order slbop tmf mutants, suggesting that SlBOPs function with additional factors. In support of this, SlBOPs interact with TMF homologs, mutations in which cause phenotypes like slbop mutants. Our findings reveal a new flowering module defined by SlBOP-TMF family interactions that ensures a progressive meristem maturation to promote inflorescence complexity.
authors: Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA.
authors: Cao
authors: C
authors: Xu
authors: Division of Biological Sciences and Research Institute for Basic Science, Wonkwang University, Iksan, Jeonbuk 54538, Republic of Korea.
authors: Soon Ju
authors: SJ
authors: Park
authors: The Boyce Thompson Institute, Ithaca, New York 14853, USA.
authors: Joyce
authors: J
authors: Van Eck
authors: Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA.
authors: Zachary B
authors: http://orcid.org/0000-0001-7668-9025
authors: ZB
authors: Lippman
mesh_terms: D000071757:BTB-POZ Domain; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D056626:Inflorescence / Q000737:chemistry / Q000235:genetics*; D018551:Solanum lycopersicum / Q000235:genetics* / Q000502:physiology; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism*
chemical_list: D010940:Plant Proteins
keywords: flowering; inflorescence; meristem; tomato