Chen Hao, Wu Wenqi, Du Kang, Yang Jun, Kang Xiangyang
State Key Laboratory of Tree Genetics and Breeding, Beijing Forestry University, Beijing, China.
National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.
Plant Cell Environ. 2025 May;48(5):3136-3150. doi: 10.1111/pce.15329. Epub 2024 Dec 19.
Chlorophyll serves as a crucial pigment in plants, essential for photosynthesis, growth, and development. Our previous study has shown that PpnCCT39 can increase leaf chlorophyll content and photosynthesis rate in poplar. However, the underlying molecular mechanisms remain unknown. In this study, we observed that overexpression of PpnCCT39 not only elevates chlorophyll content and photosynthesis, but also induces alterations in leaf morphology, basal diameter, and chloroplast structure. By performing RNA-seq on terminal buds and leaves at leaf positions 1, 3, 5, and 10, we determined that PpnCCT39 predominantly exerts its effects in young leaves. Chromatin Immunoprecipitation Sequencing (ChIP-seq) performed on PpnCCT39-overexpressing poplars identified 17 194 potential regulatory target genes. By integrating RNA-seq and ChIP-seq datasets along with validation assays for protein-DNA interactions, we determined that PpnCCT39 directly stimulated the transcription of three key genes involved in the chlorophyll biosynthesis and photosynthesis pathways: PagHO1, PagLIL3, and PagPYG7. Furthermore, protein interaction assays revealed that PpnCCT39 interacts with PagRD19 and PagATP2, localized in vesicles and mitochondria respectively, with these interactions occurring within chloroplasts. This study elucidates the molecular mechanism by which the PpnCCT39 transcription factor in poplar promotes chlorophyll biosynthesis and photosynthesis. It also highlights the critical role of PpnCCT39 in nucleocytoplasmic interactions. These findings underscore the significance of PpnCCT39 in regulating chlorophyll biosynthesis and enhancing photosynthesis through molecular design.
叶绿素是植物中的一种关键色素，对光合作用、生长和发育至关重要。我们之前的研究表明，PpnCCT39可以增加杨树叶片的叶绿素含量和光合速率。然而，其潜在的分子机制仍然未知。在本研究中，我们观察到PpnCCT39的过表达不仅提高了叶绿素含量和光合作用，还诱导了叶片形态、基部直径和叶绿体结构的改变。通过对顶芽以及第1、3、5和10叶位的叶片进行RNA测序，我们确定PpnCCT39主要在幼叶中发挥作用。对过表达PpnCCT39的杨树进行染色质免疫沉淀测序（ChIP-seq），鉴定出17194个潜在的调控靶基因。通过整合RNA测序和ChIP-seq数据集以及蛋白质-DNA相互作用的验证试验，我们确定PpnCCT39直接刺激了参与叶绿素生物合成和光合作用途径的三个关键基因的转录：PagHO1、PagLIL3和PagPYG7。此外，蛋白质相互作用试验表明，PpnCCT39分别与定位于囊泡和线粒体的PagRD19和PagATP2相互作用，这些相互作用发生在叶绿体内。本研究阐明了杨树PpnCCT39转录因子促进叶绿素生物合成和光合作用的分子机制。它还强调了PpnCCT39在核质相互作用中的关键作用。这些发现强调了PpnCCT39在通过分子设计调控叶绿素生物合成和增强光合作用方面的重要性。
