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Summary Seasonal changes in spring induce flowering by expressing the florigen, FLOWERING LOCUS T (FT), inArabidopsis.FTis expressed in unique phloem companion cells with unknown characteristics. The question of which genes are co-expressed withFTand whether they have roles in flowering remains elusive. Through tissue-specific translatome analysis, we discovered that under long-day conditions with the natural sunlight red/far-red ratio, theFT-producing cells express a gene encoding FPF1-LIKE PROTEIN 1 (FLP1). The masterFTregulator, CONSTANS (CO), controlsFLP1expression, suggestingFLP1’s involvement in the photoperiod pathway. FLP1 promotes early flowering independently ofFT,is active in the shoot apical meristem, and induces the expression ofSEPALLATA 3(SEP3), a key E-class homeotic gene. Unlike FT, FLP1 facilitates inflorescence stem elongation. Our cumulative evidence indicates that FLP1 may act as a mobile signal. Thus, FLP1 orchestrates floral initiation together with FT and promotes inflorescence stem elongation during reproductive transitions.
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TERMINAL FLOWER 1-FD complex target genes and competition with FLOWERING LOCUS T
Abstract Plants monitor seasonal cues to optimize reproductive success by tuning onset of reproduction and inflorescence architecture. TERMINAL FLOWER 1 (TFL1) and FLOWERING LOCUS T (FT) and their orthologs antagonistically regulate these life history traits, yet their mechanism of action, antagonism and targets remain poorly understood. Here, we show that TFL1 is recruited to thousands of loci by the bZIP transcription factor FD. We identify the master regulator of floral fate,LEAFY(LFY) as a target under dual opposite regulation by TFL1 and FT and uncover a pivotal role of FT in promoting flower fate viaLFYupregulation. We provide evidence that the antagonism between FT and TFL1 relies on competition for chromatin-bound FD at shared target loci. Direct TFL1-FD regulated target genes identify this complex as a hub for repressing both master regulators of reproductive development and endogenous signalling pathways. Our data provide mechanistic insight into how TFL1-FD sculpt inflorescence architecture, a trait important for reproductive success, plant architecture and yield.
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- Award ID(s):
- 1905062
- PAR ID:
- 10197736
- Publisher / Repository:
- Nature Publishing Group
- Date Published:
- Journal Name:
- Nature Communications
- Volume:
- 11
- Issue:
- 1
- ISSN:
- 2041-1723
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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