title: FOREVER YOUNG FLOWER Negatively Regulates Ethylene Response DNA-Binding Factors by Activating an Ethylene-Responsive Factor to Control Arabidopsis Floral Organ Senescence and Abscission.
abstract: In this study of Arabidopsis (Arabidopsis thaliana), we investigated the relationship between FOREVER YOUNG FLOWER (FYF) and Ethylene Response DNA-binding Factors (EDFs) and functionally analyzed a key FYF target, an Ethylene-Responsive Factor (ERF), that controls flower senescence/abscission. Ectopic expression of EDF1/2/3/4 caused promotion of flower senescence/abscission and the activation of the senescence-associated genes. The presence of a repressor domain in EDFs and the enhancement of the promotion of senescence/abscission in EDF1/2/3/4+SRDX (converting EDFs to strong repressors by fusion with the ERF-associated amphiphilic repression motif repression domain SRDX) transgenic plants suggested that EDFs act as repressors. The significant reduction of β-glucuronidase (GUS) expression by 35S:FYF in EDF1/2/3/4:GUS plants indicates that EDF1/2/3/4 functions downstream of FYF in regulating flower senescence/abscission. In this study, we also characterized an ERF gene, FOREVER YOUNG FLOWER UP-REGULATING FACTOR1 (FUF1), which is up-regulated by FYF during flower development. Ectopic expression of FUF1 caused similar delayed flower senescence/abscission as seen in 35S:FYF plants. This phenotype was correlated with deficient abscission zone formation, ethylene insensitivity, and down-regulation of EDF1/2/3/4 and abscission-associated genes in 35S:FUF1 flowers. In contrast, significant promotion of flower senescence/abscission and up-regulation of EDF1/2/3/4 were observed in 35S:FUF1+SRDX transgenic dominant-negative plants, in which FUF1 is converted to a potent repressor by fusion to an SRDX-suppressing motif. Thus, FUF1 acts as an activator in suppressing EDF1/2/3/4 function and senescence/abscission of the flowers. Our results reveal that FYF regulates flower senescence/abscission by negatively regulating EDF1/2/3/4, which is the downstream gene in the ethylene response, by activating FUF1 in Arabidopsis.
authors.affiliation: Institute of Biotechnology (W.-H.C., P.-F.L., M.-K.C., C.-H.Y.) andAgricultural Biotechnology Center (C.-H.Y.), National Chung Hsing University, Taichung, Taiwan 40227, Republic of China; andBiology Department, National Museum of Natural Science, Taichung, Taiwan 40227, Republic of China (Y.-I.L.).
authors.forename: Wei-Han
authors.identifier: http://orcid.org/0000-0002-6295-8543
authors.initials: WH
authors.lastname: Chen
authors.affiliation: Institute of Biotechnology (W.-H.C., P.-F.L., M.-K.C., C.-H.Y.) andAgricultural Biotechnology Center (C.-H.Y.), National Chung Hsing University, Taichung, Taiwan 40227, Republic of China; andBiology Department, National Museum of Natural Science, Taichung, Taiwan 40227, Republic of China (Y.-I.L.).
authors.forename: Pei-Fang
authors.initials: PF
authors.lastname: Li
authors.affiliation: Institute of Biotechnology (W.-H.C., P.-F.L., M.-K.C., C.-H.Y.) andAgricultural Biotechnology Center (C.-H.Y.), National Chung Hsing University, Taichung, Taiwan 40227, Republic of China; andBiology Department, National Museum of Natural Science, Taichung, Taiwan 40227, Republic of China (Y.-I.L.).
authors.forename: Ming-Kun
authors.identifier: http://orcid.org/0000-0002-9150-4436
authors.initials: MK
authors.lastname: Chen
authors.affiliation: Institute of Biotechnology (W.-H.C., P.-F.L., M.-K.C., C.-H.Y.) andAgricultural Biotechnology Center (C.-H.Y.), National Chung Hsing University, Taichung, Taiwan 40227, Republic of China; andBiology Department, National Museum of Natural Science, Taichung, Taiwan 40227, Republic of China (Y.-I.L.).
authors.forename: Yung-I
authors.initials: YI
authors.lastname: Lee
authors.affiliation: Institute of Biotechnology (W.-H.C., P.-F.L., M.-K.C., C.-H.Y.) andAgricultural Biotechnology Center (C.-H.Y.), National Chung Hsing University, Taichung, Taiwan 40227, Republic of China; andBiology Department, National Museum of Natural Science, Taichung, Taiwan 40227, Republic of China (Y.-I.L.) chyang@dragon.nchu.edu.tw.
authors.forename: Chang-Hsien
authors.initials: CH
authors.lastname: Yang
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D005030:Ethylenes / Q000494:pharmacology*; D035264:Flowers / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D010937:Plant Growth Regulators / Q000494:pharmacology; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D005030:Ethylenes; D010937:Plant Growth Regulators; C036216:ethylene; D005966:Glucuronidase