FE, a phloem‐specific Myb‐related protein, promotes flowering through transcriptional activation of FLOWERING LOCUS T and FLOWERING LOCUS T INTERACTING PROTEIN 1. (September 2015)

• Record Type: Journal Article
• Authors: Abe, Mitsutomo; Kaya, Hidetaka; Watanabe‐Taneda, Ayako; Shibuta, Mio; Yamaguchi, Ayako; Sakamoto, Tomoaki; Kurata, Tetsuya; Ausín, Israel; Araki, Takashi; Alonso‐Blanco, Carlos
• Is Part Of: Plant journal. Volume 83:Number 6(2015:Sep.)
• Page Start: 1059
• Page End: 1068
• Publication Date: 2015-09
• Subjects: Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.12951
• Languages: English
• ISSNs: 0960-7412

Abstract

<abstract abstract-type="main" id="tpj12951-abs-0001"> <title>Summary</title> <p>In many flowering plants, the transition to flowering is primarily affected by seasonal changes in day length (photoperiod). An inductive photoperiod promotes flowering via synthesis of a floral stimulus, called florigen. In <italic>Arabidopsis thaliana</italic>, the FLOWERING LOCUS T (FT) protein is an essential component of florigen, which is synthesized in leaf phloem companion cells and is transported through phloem tissue to the shoot apical meristem where floral morphogenesis is initiated. However, the molecular mechanism involved in the long‐distance transport of FT protein remains elusive. In this study, we characterized the classic Arabidopsis mutant <italic>fe</italic>, which is involved in the photoperiodic induction of flowering, and showed that <italic>FE</italic> encodes a phloem‐specific Myb‐related protein that was previously reported as ALTERED PHLOEM DEVELOPMENT. Phenotypic analyses of the <italic>fe</italic> mutant showed that <italic>FT</italic> expression is reduced in leaf phloem companion cells. In addition, the transport of FT protein from leaves to the shoot apex is impaired in the <italic>fe</italic> mutant. Expression analyses further demonstrated that FE is also required for transcriptional activation of <italic>FLOWERING LOCUS T INTERACTING PROTEIN 1</italic> (<italic>FTIP1</italic>), an essential regulator for selective trafficking of the FT protein from companion cells to sieve elements. These findings indicate that FE plays a dual role in the photoperiodic induction of flowering: as a transcriptional activator of <italic>FT</italic> on the one hand, and its transport machinery component, <italic>FTIP1</italic>, on the other hand. Thus, FE is likely to play a role in regulating FT by coordinating FT synthesis and FT transport in phloem companion cells.</p> </abstract>