BROTHER OF FT AND TFL1 (BFT) has TFL1-like activity and functions redundantly with TFL1 in inflorescence meristem development in Arabidopsis.
The FLOWERING LOCUS T (FT)/TERMINAL FLOWER 1 (TFL1) family is a small gene family that encodes important regulators that control flower development in Arabidopsis. Here, we investigated the biological role of the product of BROTHER OF FT AND TFL1 (BFT), a member of this family, whose function remains unknown. Comparison of the critical residues that play a role in distinguishing FT- or TFL1-like activity revealed that BFT is more similar to FT. Similar to FT expression, BFT expression showed a diurnal oscillation pattern, peaking in the evening. In situ hybridization revealed BFT expression in the shoot apical meristem, young leaf and axillary inflorescence meristem. Transgenic plants over-expressing BFT exhibited delayed flowering and severe floral defects (floral indeterminacy and compact inflorescences surrounded by serrate leaves), similar to 35S::TFL1 plants. LEAFY (LFY) and APETALA1 (AP1) expression was significantly reduced in 35S::BFT plants. BFT over-expression failed to rescue the terminal flower phenotype of tfl1 mutants; however, it delayed both terminal flower formation in the primary inflorescence and axillary inflorescence development in the tfl1 mutant background. Consistent with this, the loss-of-function BFT alleles, bft-2 and an BFT RNAi line, accelerated termination of the primary inflorescence and formation of axillary inflorescences in the tfl1 mutant background. Taken together, our results suggest that, despite similarities in the critical residues of BFT and FT, BFT possesses a TFL1-like activity and functions redundantly with TFL1 in inflorescence meristem development, and possibly contributes to the regulation of plant architecture.
Yoo
Seong Jeon
SJ
Creative Research Initiative, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea.
Chung
Kyung Sook
KS
Creative Research Initiative, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea.
Jung
Seung Hye
SH
Creative Research Initiative, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea.
Yoo
So Yeon
SY
Creative Research Initiative, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea.
Lee
Jong Seob
JS
School of Biological Sciences, Seoul National University, Seoul 151-742, Korea.
Ahn
Ji Hoon
JH
Creative Research Initiative, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea.
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D056626:Inflorescence / Q000254:growth & development*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D018519:Meristem / Q000254:growth & development*; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development; D018749:RNA, Plant / Q000235:genetics; D017422:Sequence Analysis, DNA
D029681:Arabidopsis Proteins; C568223:BFT protein, Arabidopsis; D008565:Membrane Proteins; D018749:RNA, Plant; C102864:TFL1 protein, Arabidopsis
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