Tuning growth cycles of Brassica crops via natural antisense transcripts of BrFLC
作者单位：National Key Laboratory of Plant Molecular GeneticsShanghai Institute of Plant Physiology and EcologyShanghai Institutes for Biological SciencesChinese Academy of Sciences
会议名称：《2016年全国植物生物学大会》
会议日期：2016年
学科分类：0710[理学-生物学] 07[理学] 09[农学] 071007[理学-遗传学] 0901[农学-作物学] 090102[农学-作物遗传育种]
关 键 词：Brassica rapa BrFLC natural antisense transcripts flowering time growth cycle vernalization
摘 要：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(Br FLC) 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 nonsense mutations and are non-functional 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.