title: Homologs of FT, CEN and FD respond to developmental and environmental signals affecting growth and flowering in the perennial vine kiwifruit.
abstract: FLOWERING LOCUS T (FT) and CENTRORADIALIS (CEN) homologs have been implicated in regulation of growth, determinacy and flowering. The roles of kiwifruit FT and CEN were explored using a combination of expression analysis, protein interactions, response to temperature in high-chill and low-chill kiwifruit cultivars and ectopic expression in Arabidopsis and Actinidia. The expression and activity of FT was opposite from that of CEN and incorporated an interaction with a FLOWERING LOCUS D (FD)-like bZIP transcription factor. Accumulation of FT transcript was associated with plant maturity and particular stages of leaf, flower and fruit development, but could be detected irrespective of the flowering process and failed to induce precocious flowering in transgenic kiwifruit. Instead, transgenic plants demonstrated reduced growth and survival rate. Accumulation of FT transcript was detected in dormant buds and stem in response to winter chilling. In contrast, FD in buds was reduced by exposure to cold. CEN transcript accumulated in developing latent buds, but declined before the onset of dormancy and delayed flowering when ectopically expressed in kiwifruit. Our results suggest roles for FT, CEN and FD in integration of developmental and environmental cues that affect dormancy, budbreak and flowering in kiwifruit.
authors.affiliation: The New Zealand Institute for Plant & Food Research Limited (Plant & Food Research), Private Bag 92169, Auckland, 1142, New Zealand.
authors.forename: Erika
authors.initials: E
authors.lastname: Varkonyi-Gasic
authors.affiliation: The New Zealand Institute for Plant & Food Research Limited (Plant & Food Research), Private Bag 92169, Auckland, 1142, New Zealand.
authors.forename: Sarah M A
authors.initials: SMA
authors.lastname: Moss
authors.affiliation: The New Zealand Institute for Plant & Food Research Limited (Plant & Food Research), Private Bag 92169, Auckland, 1142, New Zealand.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Voogd
authors.affiliation: The New Zealand Institute for Plant & Food Research Limited (Plant & Food Research), Private Bag 92169, Auckland, 1142, New Zealand.
authors.forename: Tianchi
authors.initials: T
authors.lastname: Wang
authors.affiliation: Flowering Laboratory, School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand.
authors.forename: Joanna
authors.initials: J
authors.lastname: Putterill
authors.affiliation: The New Zealand Institute for Plant & Food Research Limited (Plant & Food Research), Private Bag 92169, Auckland, 1142, New Zealand.
authors.forename: Roger P
authors.initials: RP
authors.lastname: Hellens
mesh_terms: D029042:Actinidia / Q000235:genetics* / Q000254:growth & development*; D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D035264:Flowers / Q000235:genetics* / Q000254:growth & development; D005638:Fruit / Q000235:genetics / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018547:Plant Stems / Q000235:genetics; D030821:Plants, Genetically Modified; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013696:Temperature; D014157:Transcription Factors / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; C503117:FD protein, Arabidopsis; C418905:FT protein, Arabidopsis; D010940:Plant Proteins; C102864:TFL1 protein, Arabidopsis; D014157:Transcription Factors