Guo Tao, Bao Fen, Fan Yingming, Zhang Jinfeng, Zhao Jian
State Key Laboratory of Efficient Production of Forest Resources, National Engineering Research Center of Tree Breeding and Ecological Restoration, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.
Hortic Res. 2024 Jul 10;11(8):uhae180. doi: 10.1093/hr/uhae180. eCollection 2024 Aug.
Somatic embryogenesis (SE) is not only the most effective method among various strategies for the asexual propagation of forest trees but also a basis for genetic improvement. However, some bottlenecks, such as the recalcitrance of initiation, the maintenance of embryogenic potential during proliferation and the low efficiency of maturation as well as high rate of abnormal embryo development remain unresolved. These bottlenecks refer to complex mechanisms, including transcriptional regulatory networks, epigenetic modifications and physiological conditions. In recent years, several small molecules utilized in animal stem cell research have exhibited positive effects on plant regeneration, including conifer species, which offers a potential novel approach to overcome the challenges associated with SE in conifers. In this review, we summarize the small molecules used in conifers, including redox substances, epigenetic regulatory inhibitors and other metabolism-related molecules, which overcome these difficulties without the use of genetic engineering. Moreover, this approach also has the advantages of dynamic reversibility, simple operation, and simultaneous regulation of multiple targets, which might be one of the best choices for optimizing plant regeneration systems including SE.
体细胞胚胎发生（SE）不仅是林木无性繁殖各种策略中最有效的方法，也是遗传改良的基础。然而，一些瓶颈问题仍未得到解决，例如起始的顽拗性、增殖过程中胚性潜能的维持、成熟效率低下以及异常胚胎发育率高。这些瓶颈涉及复杂的机制，包括转录调控网络、表观遗传修饰和生理条件。近年来，动物干细胞研究中使用的几种小分子对植物再生表现出积极影响，包括针叶树种，这为克服针叶树体细胞胚胎发生相关挑战提供了一种潜在的新方法。在本综述中，我们总结了针叶树中使用的小分子，包括氧化还原物质、表观遗传调控抑制剂和其他代谢相关分子，这些小分子无需基因工程即可克服这些困难。此外，这种方法还具有动态可逆性、操作简单和多靶点同时调控的优点，这可能是优化包括体细胞胚胎发生在内的植物再生系统的最佳选择之一。
