title: Precocious flowering in trees: the FLOWERING LOCUS T gene as a research and breeding tool in Populus.
abstract: Expression of FLOWERING LOCUS T (FT) and its homologues has been shown to accelerate the onset of flowering in a number of plant species, including poplar (Populus spp.). The application of FT should be of particular use in forest trees, as it could greatly accelerate and enable new kinds of breeding and research. Recent evidence showing the extent to which FT is effective in promoting flowering in trees is discussed, and its effectiveness in poplar is reported. Results using one FT gene from Arabidopsis and two from poplar, all driven by a heat-inducible promoter, transformed into two poplar genotypes are also described. Substantial variation in flowering response was observed depending on the FT gene and genetic background. Heat-induced plants shorter than 30 cm failed to flower as well as taller plants. Plants exposed to daily heat treatments lasting 3 weeks tended to produce fewer abnormal flowers than those in heat treatments of shorter durations; increasing the inductive temperature from 37 degrees C to 40 degrees C produced similar benefits. Using optimal induction conditions, approximately 90% of transgenic plants could be induced to flower. When induced FT rootstocks were grafted with scions that lacked FT, flowering was only observed in rootstocks. The results suggest that a considerable amount of species- or genotype-specific adaptation will be required to develop FT into a reliable means for shortening the generation cycle for breeding in poplar.
authors.affiliation: Northwest A&F University, College of Forestry, Yangling, 712100 People's Republic of China.
authors.forename: Huanling
authors.initials: H
authors.lastname: Zhang
authors.forename: David E
authors.initials: DE
authors.lastname: Harry
authors.forename: Cathleen
authors.initials: C
authors.lastname: Ma
authors.forename: Cetin
authors.initials: C
authors.lastname: Yuceer
authors.forename: Chuan-Yu
authors.initials: CY
authors.lastname: Hsu
authors.forename: Vikas
authors.initials: V
authors.lastname: Vikram
authors.forename: Olga
authors.initials: O
authors.lastname: Shevchenko
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Etherington
authors.forename: Steven H
authors.initials: SH
authors.lastname: Strauss
mesh_terms: D017360:Arabidopsis / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics; D001901:Botany / Q000379:methods*; D001947:Breeding; D002999:Clone Cells; D035264:Flowers / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development; D005638:Fruit / Q000033:anatomy & histology; D017343:Genes, Plant / Q000235:genetics*; D005838:Genotype; D006358:Hot Temperature; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D011058:Pollen / Q000254:growth & development; D032107:Populus / Q000033:anatomy & histology / Q000235:genetics*; D012106:Research; D014197:Trees / Q000235:genetics*
chemical_list: D029681:Arabidopsis Proteins; C418905:FT protein, Arabidopsis; D010940:Plant Proteins