title: Long-distance movement of Arabidopsis FLOWERING LOCUS T RNA participates in systemic floral regulation.
abstract: The finding of mRNA acting as a systemic information molecule is one of the most exciting discoveries in recent plant biology. However, evidence demonstrating the functional significance of non-cell autonomous RNA remains limited. Recent analyses of Arabidopsis and rice revealed FLOWERING LOCUS T (FT) protein as a systemic florigenic signal. However, whether the FT RNA also participates in systemic floral regulation remains controversial. By using Arabidopsis cleft-grafting experiments, we showed that the RNA of Arabidopsis FT undergoes long-distance movement from the stock to the scion apex in both FT transformants and non-transformants. In addition, the sequences of FT RNA are sufficient to target a cell-autonomous RNA for long-distance movement. Therefore, FT RNA is a bona fide non-cell autonomous RNA. To examine the systemic action of FT RNA, we uncoupled the movement of FT RNA from protein by fusing FT with RED FLUORESCENT PROTEIN (RFP). When RFP-FT protein was retained in companion cells, the detection of RFP-FT RNA correlates with floral promotion in the scion. Further depletion of the translocated RFP-FT RNA by RNAi or artificial miRNA against FT delayed the floral promotion, indicating that the translocated FT RNA acts as a part of the systemic floral signaling. Our results indicate that both FT RNA and protein move long distance and act redundantly to integrate the photoperiodic signals.
authors.affiliation: Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung-Hsing University and Academia Sinica, Taipei, Taiwan.
authors.forename: Kuan-Ju
authors.initials: KJ
authors.lastname: Lu
authors.forename: Nien-Chen
authors.initials: NC
authors.lastname: Huang
authors.forename: Yu-Shan
authors.initials: YS
authors.lastname: Liu
authors.forename: Chung-An
authors.initials: CA
authors.lastname: Lu
authors.forename: Tien-Shin
authors.initials: TS
authors.lastname: Yu
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D035264:Flowers / Q000235:genetics* / Q000254:growth & development; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D017440:Photoperiod; D030821:Plants, Genetically Modified; D034443:RNA Transport; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000235:genetics / Q000254:growth & development; D000097573:Red Fluorescent Protein
chemical_list: D029681:Arabidopsis Proteins; D036341:Intercellular Signaling Peptides and Proteins; D008164:Luminescent Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; D011993:Recombinant Fusion Proteins; D000097573:Red Fluorescent Protein; C418905:FT protein, Arabidopsis