活性氧对杨树不定芽诱导的调控机理研究

基于器官再生方式的组织培养技术是植物再生能力的重要利用，能快速进行良种繁育。但木本植物外植体易褐化、再生能力低，建立稳定高效再生体系是其亟待解决的技术难点。活性氧(ROS)与植物再生密切相关，但关于ROS调控再生的机理鲜有报道。前期研究发现毛果杨和南林"895"叶片诱导不定芽差异很大，NBT原位染色显示ROS水平和空间分布均不同；当添加不同浓度的过氧化氢后，不定芽诱导被抑制，而生根效率随浓度增加而升高。由此可见ROS可以调控叶片再生方向和再生效率。本项目拟以上述两种杨树为研究对象，研究不定芽诱导过程中不同ROS差异激活再生相关基因表达从而影响不定芽再生的调控机理；筛选出叶片不定芽再生过程中特异表达的WOXs基因，解析WOXs影响ROS及再生相关基因表达的调控机制。深入研究ROS调控杨树不定芽再生机理，可为解决木本植物再生技术瓶颈，优化无性繁殖技术提供理论基础，更好服务树木资源的开发和利用。

Plant regeneration is applicated widely for fast propagation mostly via de novo organogenesis. However, woody plant regeneration is more complicated because of low competence due to secondary metabolites, such as polyphenols. Reactive oxygen species (ROS) is tightly correlated to the stress during plant regeneration. However, no molecular link between ROS and the competence at the transcriptional level has been established. In Populus trichocarpa and hybrid poplar (Populus deltoides × Populus euramericana cv. ‘Nanlin 895’), ROS leaves and distributions in leaves were quite different after induction on SIM with NBT staining. We proposed that ROS may regulate the way of regeneration and the efficiency. In this project, we will investigate the ROS levels in the two poplar leaves, and induce the perturbation of ROS homeostasis by adjusting the medium with ROS related chemicals and enzyme inhibitors. Combing with transcriptomic profiling, we want to explore how ROS transduce the regeneration signal during poplar organogenesis. Furthermore, we will mutate the specific expressed WOXs during leaf organogenesis to genetically uncover the mechanism of regeneration induced by ROS perturbation. Collectively, these studies will help to overcome the current difficulties and develop protocols for mass propagation of more woody plant species.