生长素的动态分布与小立碗藓离体小叶细胞再生关系的研究

Plant regeneration regulate-mechanism is one of the most important parts of normal plant development. The explant of Physcomitrella patens can regenerate without any external hormone treatment. It is a novel material for plant regeneration investigation. Former results of our lab has elucidated that the dynamic distribution of auxin takes important part in the single cell regeneration of explant leaflets. There have already some tissue specific expression genes been reported together with some auxin related genes in Physcomitrella patens. They can be very nice marker genes for cell regeneration and auxin dynamic distribution observation. There is only one single cell layer in the Physcomitrella leaflet. It's much easier to descript the distribution of auxin signal and cell regeneration in Physcomitrella leaflet than in tissues in other higher land plants such as Arabidopsis. In this project proposal, we will build up several Physcomitrella transgenic marker lines and observe the expression pattern of the auxin related genes together with the regeneration situation of the cells in the leaflet explants. We will sum up the dynamic distribution pattern of auxin during the regeneration of leaflet explants and analyzes the relation ship between auxin distribution and cell regeneration. On the basis of that, we will design physiological experiment and gene over-expression and knock out transgenic Physcomitrella plants to further validate our conclusion.

植物再生的调控机理是研究植物生长发育的重要内容之一。模式植物小立碗藓的再生不需要外源激素刺激即可进行，是研究植物再生的良好材料。本实验室前期结果表明，生长素的动态分布与小立碗藓小叶细胞的再生关系密切。国际上已有的研究结果也为进一步研究小叶细胞的再生提供了一些组织特异性表达的标志性基因以及生长素合成、代谢和信号传导相关标记基因。小立碗藓的小叶仅有一层细胞组成，与其它高等植物组织相比，描述生长素的动态分布与细胞情况的数据明显简化。本研究计划通过构建多种报答基因的转化子，观察各类生长素相关报道基因表达的时空特异性，总结小立碗藓小叶离体后生长素的动态分布变化规律，分析其与小叶细胞的再生之间关系。并在此基础上，构建基因过量表达或敲除突变体， 设计合理的生理实验，进一步验证实验结论，为研究出高效、准确的人工调控植物细胞再生方法，提供理论依据。