title: Control of floral transition in the bioenergy crop switchgrass.
abstract: Switchgrass (Panicum virgatum L.), a perennial warm season bunchgrass native to North America, has been a target in the U.S. as a renewable bioenergy crop because of its ability to produce moderate to high biomass yield on marginal soils. Delaying flowering can increase vegetative biomass production by allowing prolonged growth before switching to the reproductive phase. Despite the identification of flowering time as a biomass trait in switchgrass, the molecular regulatory factors involved in controlling floral transition are poorly understood. Here we identified PvFT1, PvAPL1-3 and PvSL1, 2 as key flowering regulators required from floral transition initiation to development of floral organs. PvFT1 expression in leaves is developmentally regulated peaking at the time of floral transition, and diurnally regulated with peak at approximately 2 h into the dark period. Ectopic expression of PvFT1 in Arabidopsis, Brachypodium and switchgrass led to extremely early flowering, and activation of FT downstream target genes, confirming that it is a strong activator of flowering in switchgrass. Ectopic expression of PvAPL1-3 and PvSL1, 2 in Arabidopsis also activated early flowering with distinct floral organ phenotypes. Our results suggest that switchgrass has conserved flowering pathway regulators similar to Arabidopsis and rice.
authors.affiliation: Department of Plant and Soil Sciences, Institute for Agricultural Biosciences, Oklahoma State University, 3210 Sam Noble Parkway, Ardmore, OK, 73401, USA.|Biotechnology Research Institute, Chinese Academy of Agricultural Sciences (CAAS), No. 12 Zhongguancun South Street, Haidian District, Beijing, 100081, China.
authors.forename: Lifang
authors.initials: L
authors.lastname: Niu
authors.affiliation: Forage Improvement Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA.
authors.forename: Chunxiang
authors.initials: C
authors.lastname: Fu
authors.affiliation: Department of Plant and Soil Sciences, Institute for Agricultural Biosciences, Oklahoma State University, 3210 Sam Noble Parkway, Ardmore, OK, 73401, USA.|Biotechnology Research Institute, Chinese Academy of Agricultural Sciences (CAAS), No. 12 Zhongguancun South Street, Haidian District, Beijing, 100081, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Lin
authors.affiliation: Department of Plant and Soil Sciences, Institute for Agricultural Biosciences, Oklahoma State University, 3210 Sam Noble Parkway, Ardmore, OK, 73401, USA.
authors.forename: Tezera W
authors.initials: TW
authors.lastname: Wolabu
authors.affiliation: Department of Plant and Soil Sciences, Oklahoma State University, 371 Ag Hall, Stillwater, OK, 74078-6028, USA.
authors.forename: Yanqi
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Forage Improvement Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA.
authors.forename: Zeng-Yu
authors.initials: ZY
authors.lastname: Wang
authors.affiliation: Department of Plant and Soil Sciences, Institute for Agricultural Biosciences, Oklahoma State University, 3210 Sam Noble Parkway, Ardmore, OK, 73401, USA. million.tadege@okstate.edu.
authors.forename: Million
authors.initials: M
authors.lastname: Tadege
mesh_terms: D056804:Biofuels; D018533:Biomass; D003001:Cloning, Molecular; D003246:Conservation of Energy Resources; D018556:Crops, Agricultural / Q000235:genetics / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D008897:Panicum / Q000235:genetics / Q000254:growth & development*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D030821:Plants, Genetically Modified / Q000254:growth & development; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D020539:Sequence Analysis, Protein
chemical_list: D056804:Biofuels; D010940:Plant Proteins; D012333:RNA, Messenger
keywords: FT; Panicum virgatum L; PvAPL; PvFT1; PvSL; biomass feedstock; floral transition; florigen