Chen Tingting, Yuan Guoying, Lu Yan, Wang Dan, Qi Haoran, Sun Xiaowei, Hua Jianfeng, Yin Yunlong, Yu Chaoguang
Institute of Botany, Jiangsu Province and Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), No.1, Qianhu Village, Zhongshan Gate, Nanjing, 210014, China.
Jiangsu Key Laboratory for Conservation and Utilization of Plant Resources, Nanjing, 210014, China.
Plant Cell Rep. 2025 Aug 4;44(8):191. doi: 10.1007/s00299-025-03573-z.
Antioxidant-related miRNA-mRNA pairs play crucial roles in modulating the dominant embryo formation in Taxodium hybrid 'zhongshanshan'. SE (somatic embryogenesis) has been instrumental in the successful breeding of Taxodium hybrid 'zhongshanshan', a valuable timber tree species of great ecological importance. However, the underlying molecular mechanisms remain largely unknown. By examining the transcriptome and small RNA throughout the entire SE process, we observed notable differences in gene expression and miRNA profiles. DEGs (differentially expressed genes) associated with phenylpropanoid biosynthesis, glutathione metabolism, starch and sucrose metabolism, and pentose and glucuronate interconversions played pivotal roles in dominant embryo formation and cotyledonary embryo maturation. The physiological measurements showed that the contents of organic compounds were higher in embryogenic callus and cotyledonary embryo stage. Endogenous GSH (glutathione) and GSSG (oxidized glutathione disulfide) contents reached the peak values in the dominant embryo stage. Additionally, a total of 271 mature miRNAs were detected, with 244 being previously identified and 27 being novel plant miRNAs. Among these, 71 DE miRNAs (differentially expressed miRNAs) were screened out during the transition from embryogenic callus to cotyledon embryo stage of SE, which suggested that miRNAs played important roles in somatic embryo development. By predicting target genes for these DE miRNAs and conducting correlation analysis with DEGs, several key miRNA-mRNA pairs were identified, which mainly regulated the dominant embryo formation in Taxodium hybrid 'zhongshanshan'. Furthermore, the exogenous addition of 0.3 g·L GSH effectively improved SE efficiency. Taken together, this study provided valuable information in the SE of Taxodium hybrid 'zhongshanshan', thereby facilitating its breeding programs.
抗氧化相关的miRNA-mRNA对在调控杂交落羽杉‘中山杉’的优势胚形成中起关键作用。体细胞胚胎发生（SE）对杂交落羽杉‘中山杉’的成功育种至关重要，杂交落羽杉‘中山杉’是一种具有重要生态意义的珍贵用材树种。然而，其潜在的分子机制仍 largely未知。通过检查整个SE过程中的转录组和小RNA，我们观察到基因表达和miRNA谱存在显著差异。与苯丙烷生物合成、谷胱甘肽代谢、淀粉和蔗糖代谢以及戊糖和葡萄糖醛酸相互转化相关的差异表达基因（DEGs）在优势胚形成和子叶胚成熟中起关键作用。生理测量表明，胚性愈伤组织和子叶胚阶段的有机化合物含量较高。内源性谷胱甘肽（GSH）和氧化型谷胱甘肽二硫化物（GSSG）含量在优势胚阶段达到峰值。此外，共检测到271个成熟miRNA，其中244个先前已被鉴定，27个是新的植物miRNA。其中，在SE从胚性愈伤组织到子叶胚阶段的转变过程中筛选出71个差异表达miRNA（DE miRNAs），这表明miRNA在体细胞胚胎发育中起重要作用。通过预测这些DE miRNAs的靶基因并与DEGs进行相关性分析，鉴定出几个关键的miRNA-mRNA对，它们主要调控杂交落羽杉‘中山杉’的优势胚形成。此外，外源添加0.3 g·L GSH有效提高了SE效率。综上所述，本研究为杂交落羽杉‘中山杉’的SE提供了有价值的信息，从而促进其育种计划。
