miR156-SPLs网络调控黄瓜叶片夹角形成的分子机制研究

Leaf angle is the inclination of plant leaves to the main stem, which determines the photosynthetic posture of the plant and directly affects the photosynthetic efficiency and yield of the crop. Researches about the genes related to plant leaf angle and their function play important roles in the high-efficient production of crops. However，researches about molecular mechanism of cucumber plant leaf angle are very few. By detecting the leaf angle of different cucumber variety, we found that leaf angle has positive correlation with the expression of mature miR156, indicated the development of cucumber leaf angle may be regulated by miR156. But the exact molecular mechanism is unknown. In this project, we plan to carry out the analysis of genetic transformation, ChIP-seq and RNA-seq technology to screening the downstream genes, which are involved in leaf angle regulation. In addition, yeast one hybrid, yeast two hybrid and luciferase reporter gene (Luc) technology were used to determine the downstream leaf angle genes of miR156/SPLs. This results would be helpful for constructing the molecular regulation network‘miR156-SPLs- leaf angle genes’ in leaf angle development of cucumber, and also be useful for providing the oretical basis for cultivating new varieties of cucumber ideal plant.

叶片夹角是指植物叶片向主茎的倾斜度，直立的叶形能够保证植物在高种植密度下的采光度从而保证高效的光合效率和结实率。叶夹角相关基因及调控机制的研究对作物高效生产具有重要的理论和实践意义。黄瓜叶夹角相关分子机制研究较少，申请者对不同黄瓜材料统计发现，黄瓜叶片夹角与miR156成熟体表达量正相关，即叶片夹角越大，miR156在此处的表达量越高，暗示了黄瓜叶片夹角的发育可能受到miR156的调控, 但具体的分子机制未知。本项目拟通过遗传转化、ChIP-seq和转录组测序等技术挖掘miR156-SPLs下游调控叶片夹角发育的候选基因，解析下游基因的叶夹角调控功能；同时通过酵母单/双杂、荧光素酶报告系统等方法明确miR156-SPLs-叶片夹角基因在黄瓜叶夹角形成及株型调控中的生物学功能。研究结果不仅可以丰富黄瓜叶片夹角时序形成的理论知识，同时也为培育黄瓜理想株型新品种提供理论依据。

直立的叶片夹角能够保证植物在高种植密度下的采光度从而保证高效的光合效率和结实率。叶夹角相关基因及调控机制的研究对作物高效生产具有重要的理论和实践意义。本项目通过构建miR156转基因黄瓜材料系统分析其温室栽培条件下叶片夹角表型，过表达miR156增大叶夹角度数，相反抑制miR156减小叶夹角度数产生直立叶夹角表型。利用转录组测序和激素代谢组鉴定到miR156-SPLs通路可能通过赤霉素生物合成通路影响黄瓜叶夹角形成。生化实验表明SPL9可以直接结合赤霉素合成相关基因KAO1启动子激活其表达，进而影响赤霉素合成。本项目开展丰富了黄瓜叶片夹角形成的理论知识，同时也为培育黄瓜理想株型新品种提供理论依据。