月季‘绿萼’花器官突变关键转录因子的功能鉴定及调控机制研究

Rose is one of the Chinese traditional flowers, with very high ornamental and economic value. Rosa chinensis cv. Viridiflora is a floral organ mutation of Chinese old rose (floral organs mutated into leaf-like structure) and thereby a precious resource for studying floral organ development. In addition, we also obtained the floral organ reversed mutant of R. chinensis cv. Viridiflora (floral organs are all reversed), and previously, through the comparison of RNA-seq data between Rosa chinensis cv. Old Blush (nomal flower), R. chinensis cv. Viridiflora and R. chinensis cv. viridiflora ‘reversion’ and further qRT-PCR analysis and filtering, we have got 4 candidate transcription factors that tightly related the reciprocate mutation of rose floral organs, and most of them showing floral organ-specific expression, indicating their important roles in regulating rose floral organ development. In this proposal, we intend to characterize the functions of those candidate genes and further select a key transcription factor as our target through VIGS technique and study its regulatory mechanism in rose floral organ development with comprehensive manner, including in situ hybridization, RNA-seq, ChIP-Seq, promoter activation and other techniques. Our expected results will not only enrich present floral organ developmental theories, but will also provide further theoretical support for the improvement of the ornamental characters of woody ornamental plants like Rosa chinensis using molecular breeding.

月季是我国传统名花，具有极高的观赏和经济价值。‘绿萼’是中国古老月季花器官突变的活化石，是研究花器官发育的宝贵资源。在前期工作中，申请人获得了‘绿萼’花器官的回复突变体，并通过对‘月月粉’（正常花）、‘绿萼’（花器官突变）、‘绿萼回复突变体’（花器官回复突变）进行转录组测序及qRT-PCR分析，筛选到4个转录因子与‘绿萼’花器官的突变紧密相关，且其在不同花器官中具有显著的表达特异性，表明其在月季花器官发育中具有重要的调控作用。基于以上基础，本项目拟采用VIGS技术对候选基因的功能进行鉴定，并进一步筛选1个对月季花器官发育影响最为显著的关键转录因子，结合该特殊月季资源，通过原位杂交、转录组测序、ChIP-seq及启动子激活等技术，解析其在月季花器官发育中的调控机制。预期研究结果不仅可以极大地丰富植物花器官发育理论，而且可以为分子育种应用于月季等木本观赏植物性状改良提供理论支撑。

月季是我国传统名花及‘四大切花’之一，具有极高的观赏和经济价值。近年来，随着经济的发展和人们生活水平的提高，月季的种植面积及产业正在急速扩大。其中，月季相关的衍生品（比如玫瑰精油、鲜花饼、化妆品、花茶、玫瑰酒及药用等）备受人们的青睐，带来了巨大的经济附加值。花朵的大小不仅影响其观赏价值，同时还影响精油等衍生品的产量和品质。因此，月季花朵大小的分子机制研究具有重要的理论价值和应用前景。本研究发现了RcREM18基因能够显著的调控月季花朵大小（约30％），并且其依赖于花发育ABCDE模型基因的调控。研究初步取得了开创性的成果-即发现了调控植物花朵大小的新基因RcREM18，后期有望取得突破性的成果，其不仅能够填补木本植物花朵大小调控的理论空白，而且能够为改良月季观赏性状及提高精油等衍生品产量和品质等方面的分子设计育种提供理论依据，对未来新型月季产业的发展具有重要意义。项目资助发表SCI论文8篇，发明专利6项，培养研究生4名。