SPL3/4/5 Integrate Developmental Aging and Photoperiodic Signals into the FT-FD Module in Arabidopsis Flowering

• Published in: Molecular plant Vol. 9; no. 12; pp. 1647 - 1659
• Main Authors: Jung, Jae-Hoon, Lee, Hyo-Jun, Ryu, Jae Yong, Park, Chung-Mo
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 05-12-2016
• Subjects: Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis - physiology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; developmental aging; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Flowers - genetics; Flowers - metabolism; Flowers - physiology; FT-FD complex; Gene Expression Regulation, Plant; Photoperiod; photoperiodic flowering; Plants, Genetically Modified - genetics; Plants, Genetically Modified - metabolism; Plants, Genetically Modified - physiology; Signal Transduction; SPL transcription factors; Transcription Factors - genetics; Transcription Factors - metabolism; 光周期信号; 发育阶段; 开花植物; 拟南芥; 整合; 模块; 老化; 转录激活因子; SPL transcription factors; developmental aging; FT-FD complex; photoperiodic flowering
• ISSN: 1674-2052; 1752-9867
• DOI: 10.1016/j.molp.2016.10.014

Environmental sensitivity varies across developmental phases in flowering plants. In the juvenile phase, mi- croRNA156 （miR156）-mediated repression of SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE （SPL） transcription factors renders Arabidopsis plants incompetent to floral inductive signals, including long- day （LD） photoperiod. During the vegetative phase transition, which accompanies a reduction of miR156 and a concomitant elevation of its targets, plants acquire reproductive competence such that LD signals promote flowering. However, it remains largely unknown how developmental signals are associated with photoperiodic flowering. Here, we show that SPL3, SPL4, and SPL5 （SPL3/4/5） potentiate the FLOWERING LOCUS T （FT）-FD module in photoperiodic flowering. SPL3/4/5 function as transcriptional activators through the interaction with FD, a basic leucine zipper transcription factor which plays a critical role in photoperiodic flowering. SPL3/4/5 can directly bind to the promoters of APETALA1, LEAFY, and FRUITFULL, thus mediating their activation by the FT-FD complex. Our findings demonstrate that SPL3/ 4/5 act synergistically with the FT-FD module to induce flowering under LDs, providing a long-sought mo- lecular knob that links developmental aging and photoperiodic flowering.