Although the leaf is the most important photosynthetic organ in most plants, many of the molecular mechanisms underlying leaf developmental dynamics remain to be explored. To better understand the transcriptional regulatory mechanisms involved in leaf development, we conducted comparative transcriptomic and metabolomic analysis of leaves from seven positions on tobacco (Nicotiana tabacum) plants. A total of 35,622 unique differentially expressed genes and 79 metabolites were identified. A time-series expression analysis detected two interesting transcriptional profiles, one comprising 10,197 genes that displayed continual up-regulation during leaf development and another comprising 4696 genes that displayed continual down-regulation. Combining these data with co-expression network results identified four important regulatory networks involved in photorespiration and the tricarboxylic acid cycle; these networks may regulate carbon/nitrogen balance during leaf development. We also found that the transcription factor NtGATA5 acts as a hub associated with C and N metabolism and chloroplast development during leaf development through regulation of phytohormones. Furthermore, we investigated the transcriptional dynamics of genes involved in the auxin, cytokinin, and jasmonic acid biosynthesis and signaling pathways during tobacco leaf development. Overall, our study greatly expands the understanding of the regulatory network controlling developmental dynamics in plant leaves.

尽管叶子是大多数植物中最重要的光合器官，但叶子发育动力学的许多分子机制仍有待探索。为了更好地了解叶片发育中涉及的转录调控机制，我们对烟草（ Nicotiana tabacum ）植物的七个位置的叶片进行了比较转录组学和代谢组学分析。总共鉴定出 35,622 个独特的差异表达基因和 79 种代谢物。时间序列表达分析检测到两个有趣的转录谱，一个包含 10,197 个在叶子发育过程中表现出持续上调的基因，另一个包含 4696 个表现出持续下调的基因。将这些数据与共表达网络结果相结合，确定了涉及光呼吸和三羧酸循环的四个重要调节网络；这些网络可以调节叶子发育过程中的碳/氮平衡。我们还发现转录因子 NtGATA5 通过调节植物激素在叶子发育过程中充当与 C 和 N 代谢以及叶绿体发育相关的枢纽。此外，我们研究了烟叶发育过程中参与生长素、细胞分裂素和茉莉酸生物合成和信号通路的基因的转录动态。总的来说，我们的研究极大地扩展了对控制植物叶片发育动态的调控网络的理解。