Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu, China.
PeerJ. 2022 Feb 2;10:e12615. doi: 10.7717/peerj.12615. eCollection 2022.
The unique 'mandarin jacket' leaf shape is the most famous trait of and this characteristic gives aesthetic and landscaping value. However, the underlying regulatory mechanism of genes involved in the leaf development of has remained unclear.
Based on transcriptome data of leaves at different developmental stages from , we identified differentially expression genes (DEGs) functioning in leaf development. A candidate gene named () had high similarity in sequence with , and used for further research. We isolated the full-length gene and its promoter from . Subsequently, we analyzed the function of the gene and its promoter activity via transformation into .
In this study, we found that the and are homologous in sequence but not homologous in function. Unlike the role of in leaf serration and SAM formation, the mainly regulates cotyledon development and rosette leaf number. Histochemical -glucuronidase (GUS) staining revealed that was expressed in the cotyledons of seedlings, indicating that the may play a role in cotyledon development. Ectopic expression of resulted in long, narrow cotyledons without petioles, abnormal lamina epidermis cells and defective vascular tissue in cotyledons, and these results were consistent with the expression pattern. Further analysis showed that overexpression of also induced numerous rosette leaves. Also, and other related genes showed a severe response in by introducing exogenous auxin stimulation, partly revealed that affects the leaf development by regulating the auxin content.
These results suggest that may play a critical role in leaf development and morphogenesis in , and our findings provide insight into the molecular mechanisms of leaf development in .
“马褂形”叶片是 最具特色的形态特征，具有较高的观赏和园林价值。然而，其叶片发育相关基因的调控机制尚不清楚。
基于不同发育阶段叶片的转录组数据，鉴定出参与叶片发育的差异表达基因（DEGs）。序列与 高度相似的候选基因 （）被认为与叶片发育有关，用于进一步研究。我们从 中分离出全长 基因及其启动子，随后通过转化到 中分析 基因及其启动子的功能。
本研究发现 与 序列同源但功能不同。与 调控叶片锯齿和 SAM 形成的功能不同， 主要调控子叶发育和莲座叶数量。组织化学-GUS 染色显示 基因在 幼苗的子叶中表达，表明 可能在子叶发育中起作用。异位表达 导致子叶长而窄、无叶柄，叶片表皮细胞异常，维管束组织缺陷，这些结果与 的表达模式一致。进一步分析表明，过表达 也诱导了大量的莲座叶。此外， 与其他相关基因在外源生长素刺激下在 中表现出严重的响应，部分表明 通过调节生长素含量影响叶片发育。
这些结果表明， 可能在 叶片发育和形态发生中发挥关键作用，我们的研究结果为 叶片发育的分子机制提供了新的见解。
