Du Jingxia, Shao Chunxue, Wang Dong, Feng Zizhuo, Cui Chuwen, Li Ruili, Jewaria Pawan Kumar, Wang Xuanyi, Xiao Jianwei, Wang Xinwei
State Key Laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing, 100083, China; College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China.
College of Agriculture and Forestry, Hebei North University, Zhangjiakou, 075000, China.
Plant Physiol Biochem. 2025 Jun;223:109789. doi: 10.1016/j.plaphy.2025.109789. Epub 2025 Mar 13.
The PtrDJ1C gene is essential for poplar growth and early chloroplast development. Disruption of PtrDJ1C expression results in an albino leaf phenotype and increased branching. However, the underlying mechanism for the increased branching remains unknown. In this study, we employed integrated approaches to investigate the function of PtrDJ1C in the branch-increasing phenotype. Our results revealed that levels of indole-3-acetic acid (IAA), gibberellin (GA), and abscisic acid (ABA) were significantly reduced in ptrdj1c mutants, while cytokinin (CK) levels were slightly increased. Transcriptomic and proteomic analyses identified several key genes and proteins involved in hormone regulation and branching development that were differentially expressed. Specifically, the expression levels of TAA, ZEP, and GA20ox-genes involved in IAA, GA, and ABA biosynthesis-were significantly reduced in ptrdj1c, while IPT and LOG, which regulate CK synthesis, were upregulated. Moreover, immunoblot analysis further validated reduced levels of key biosynthetic enzymes for IAA, GA, and ABA, alongside increased levels of IPT and LOG enzymes. Interestingly, our findings suggest that hormone signaling pathways act in concert with the transcription factor WUSCHEL (WUS) to synergistically promote branching development. These results provide novel insight into the regulatory role of PtrDJ1C in hormone balance and its downstream effects on poplar branching.
PtrDJ1C基因对杨树生长和早期叶绿体发育至关重要。PtrDJ1C表达的破坏导致叶片白化表型并增加分枝。然而，分枝增加的潜在机制仍然未知。在本研究中，我们采用综合方法研究PtrDJ1C在分枝增加表型中的功能。我们的结果表明，ptrdj1c突变体中吲哚-3-乙酸（IAA）、赤霉素（GA）和脱落酸（ABA）的水平显著降低，而细胞分裂素（CK）水平略有增加。转录组学和蛋白质组学分析确定了几个参与激素调节和分枝发育的关键基因和蛋白质，它们的表达存在差异。具体而言，参与IAA、GA和ABA生物合成的TAA、ZEP和GA20ox基因在ptrdj1c中的表达水平显著降低，而调节CK合成的IPT和LOG则上调。此外，免疫印迹分析进一步证实了IAA、GA和ABA关键生物合成酶水平降低，同时IPT和LOG酶水平增加。有趣的是，我们的研究结果表明，激素信号通路与转录因子WUSCHEL（WUS）协同作用，共同促进分枝发育。这些结果为PtrDJ1C在激素平衡中的调节作用及其对杨树分枝的下游影响提供了新的见解。
