‘无刺光叶蔷薇’响应低温调控开花的候选基因研究

	‘无刺光叶蔷薇’响应低温调控开花的候选基因研究
	蒋晓东
导师	胡金勇
关键词	食用玫瑰，‘无刺光叶蔷薇’，低温，开花，LFLC，FT Edible rose, R. wichuraiana ‘Basye’s Thornless’, Low temperature, Flowering, LFLC, FT
摘要	开花时间不仅是植物生活史中最关键的转型节点，也是几乎所有农作物最重要的经济学性状之一。玫瑰鲜花饼是云南极具特色的“伴手礼”，其主要原材料为一年偶尔二次开花月季种质‘滇红’，如何实现鲜花实时持续供应是产业亟待解决的关键问题。月季开花是自身遗传因子和环境因素共同作用的结果，环境因素介导的开花调控机制研究具重要生物学和经济学价值。目前，月季开花调控主要围绕模式植物开花调控网络中CO、FT、SOC1和KSN/TFL1等重要节点基因展开，而月季如何响应低温并协调自身开花时间的研究较少。低温是‘无刺光叶蔷薇’和绝大多数中国主栽食用玫瑰等种质开花的必要条件，而具连续开花习性的‘月月粉’等古老月季和大部分现代月季开花却几乎不需要低温。因此，厘清低温调控开花的分子机理对解析月季连续开花这一关键性状驯化机制也非常重要，并能为多年生木本作物的精准靶向性育种储备重要候选基因资源。基于已构建高质量基因组的‘无刺光叶蔷薇’和‘月月粉’等研究试材，论文应用比较转录组、分子遗传和演化生物学等方法手段对月季响应低温促进开花的分子机制进行了初探。主要结果包括： 1.系统采集并构建了月季叶片和茎尖组织的年度动态转录组数据库，发现‘无刺光叶蔷薇’的生长分为休眠、开花和营养生长等三个阶段，二月底三月初为‘无刺光叶蔷薇’在昆明开花转型时期。表达聚类和基因组学分析识别到了前人在月季中未鉴定到的类FLC（LIKE FLC，LFLC），月季中LFLC及开花素编码基因FT-like和SVP等家族基因的表达均能响应低温的周期性变化。LFLC可能的下游基因FT2表达在其表达达到一定水平后启动并随之升高。LFLC表达受低温诱导，并与‘无刺光叶蔷薇’开花过程紧密正相关；拟南芥中异源表达LFLC导致早花并与拟南芥FT表达正相关，表明其在拟南芥中可能为开花促进因子。 2.LFLC潜在靶标基因FT在月季中有两个拷贝，其中FT1-like为蔷薇科植物共有，而FT2-like为月季等蔷薇亚科植物所特有，并可能源于蔷薇亚科植物共同祖先的随机复制。已知月季FT的研究均围绕FT2-like展开；但RNA-seq和定量表达分析均表明FT1-like可能也参与了开花调控。两个FT-like呈现显著组织特异性表达，并与其启动子内顺式作用元件差异谱一致，意味着二者存在功能分化，推测FT1-like参与调控光周期响应及芽休眠，而FT2-like则参与低温响应及花发育调控等。论文识别了月季LFLC和FT-like等重要候选基因，研究了其与低温周期响应及开花时间调控的关联，为进一步通过分子遗传学等手段探索月季开花调控机制储备了重要候选基因资源。; Flowering time is not only the most critical transition point in plants life history, it is also one of the most important economic traits for almost all crops. The rose flower cake is a very special edible rose ‘gift’ in Yunnan, China, but its main raw material is occasionally re-blooming rose germplasm ‘Dian Hong’, how to achieve the real-time and continuous supply of flowers has also become a key problem to be solved urgently in industries. The flowering of rose is the result of combination of its own gentic and environmental factors, and the study of flowering regulation mechanisms and environmental interactions is of great biological and economic value. At present, the flowering regulation of rose is mainly focused on CO, FT, SOC1 and KSN/TFL1, which are important integrating genes in the model plant flowering regulation network, while there is less study on how rose respond to low temperature to regulate flowering time. Meanwhile, low temperature is a necessary condition for the flowering of Rosa wichuraiana ‘Basye’s Thornless’ and the most of edible roses in China, while the Chinese ancient roses such as R. chinensis ‘Old Blush’ and most modern roses which have a continuous flowering habit hardly need it. Therefore, clarifying the molecular mechanism of low temperature regulation of flowering is also important for resolving the domestication mechanism of the key trait of continuous flowering in the rose, and it also provide important candidate genetic resources for precision breeding in perennial woody crops. Based on the high-quality genomes of R. wichuraiana ‘Basye’s Thornless’ and R. chinensis ‘Old Blush’, this paper applies comparative transcriptome, molecular genetics and evolutionary biology methods to explore the molecular mechanism of rose response to low temperature to promote flowering. The main results include: 1. An annual dynamic transcriptome database was systematically collected and constructed for the leaf and shoot apical meristem of R. wichuraiana ‘Basye’s Thornless’, which revealed that the growth of R. wichuraiana ‘Basye’s Thornless’ was divided into three stages, including dormancy, flowering and vegetative growth, and late February/early March is the flowering transition period of R. wichuraiana ‘Basye’s Thornless’ in Kunming. Expression clustering and genomic analysis identified an FLC-like (LIKE FLC, LFLC) gene that not identified in previously study of rose. And the expression of LFLC and florigen-encoding genes FT-like and SVP family genes in rose are all response to low temperature cycle changes. The possible downstream gene FT2 is activated after its expression reaches a certain level and then increases. And the expression of LFLC is induced by low temperature and is closely and positively correlated with flowering of R. wichuraiana ‘Basye’s Thornless’; Heterologous expression of LFLC in Arabidopsis leads to early flowering and is positively correlated with FT expression, suggesting that it may be a flowering-p
语种	中文
	2022-05
学位授予单位	中国科学院大学
文献类型	学位论文
条目标识符	http://ir.kib.ac.cn/handle/151853/75191
专题	昆明植物所硕博研究生毕业学位论文
推荐引用方式 GB/T 7714	蒋晓东. ‘无刺光叶蔷薇’响应低温调控开花的候选基因研究[D]. 中国科学院大学,2022.

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