title: Tuning growth cycles of Brassica crops via natural antisense transcripts of BrFLC.
abstract: Several oilseed and vegetable crops of Brassica are biennials that require a prolonged winter cold for flowering, a process called vernalization. FLOWERING LOCUS C (FLC) is a central repressor of flowering. Here, we report that the overexpression of natural antisense transcripts (NATs) of Brassica rapa FLC (BrFLC) greatly shortens plant growth cycles. In rapid-, medium- and slow-cycling crop types, there are four copies of the BrFLC genes, which show extensive variation in sequences and expression levels. In Bre, a biennial crop type that requires vernalization, five NATs derived from the BrFLC2 locus are rapidly induced under cold conditions, while all four BrFLC genes are gradually down-regulated. The transgenic Bre lines overexpressing a long NAT of BrFLC2 do not require vernalization, resulting in a gradient of shortened growth cycles. Among them, a subset of lines both flower and set seeds as early as Yellow sarson, an annual crop type in which all four BrFLC genes have non-sense mutations and are nonfunctional in flowering repression. Our results demonstrate that the growth cycles of biennial crops of Brassica can be altered by changing the expression levels of BrFLC2 NATs. Thus, BrFLC2 NATs and their transgenic lines are useful for the genetic manipulation of crop growth cycles.
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Li
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.|Graduate School of the Chinese Academy of Sciences, Shanghai, China.
authors.forename: Shaofeng
authors.initials: S
authors.lastname: Zhang
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Jinjuan
authors.initials: J
authors.lastname: Bai
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Yuke
authors.initials: Y
authors.lastname: He
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D001937:Brassica / Q000235:genetics* / Q000254:growth & development*; D003080:Cold Temperature; D018556:Crops, Agricultural / Q000235:genetics* / Q000254:growth & development*; D015536:Down-Regulation / Q000235:genetics; D035264:Flowers / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005810:Multigene Family; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D016372:RNA, Antisense / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation / Q000235:genetics
chemical_list: D010940:Plant Proteins; D016372:RNA, Antisense
keywords: BrFLC; Brassica rapa; flowering time; growth cycle; natural antisense transcripts; vernalization