Department of Life Sciences, POSTECH Biotech Center, Pohang University of Science and Technology, Pohang 37673, Korea.
Department of Industrial Plant Science & Technology, College of Agriculture, Life & Environmental Sciences, Chungbuk National University, Cheongju 28644, Korea.
Mol Plant. 2023 Jul 3;16(7):1131-1145. doi: 10.1016/j.molp.2023.05.010. Epub 2023 Jun 1.
Vascular cambium produces the phloem and xylem, vascular tissues that transport resources and provide mechanical support, making it an ideal target for crop improvement. However, much remains unknown about how vascular cambium proliferates. In this study, through pharmaceutical and genetic manipulation of reactive oxygen species (ROS) maxima, we demonstrate a direct link between levels of ROS and activity of LATERAL ORGAN BOUNDARIES DOMAIN 11 (LBD11) in maintaining vascular cambium activity. LBD11 activates the transcription of several key ROS metabolic genes, including PEROXIDASE 71 and RESPIRATORY BURST OXIDASE HOMOLOGS D and F, to generate local ROS maxima in cambium, which in turn enhance the proliferation of cambial cells. In a negative feedback mechanism, higher ROS levels then repress LBD11 expression and maintain the balance of cambial cell proliferation. Our findings thus reveal the role of a novel LBD11/ROS-dependent feedback regulatory system in maintaining vascular cambium-specific redox homeostasis and radial growth in plants.
维管形成层产生韧皮部和木质部，这是运输资源和提供机械支持的血管组织，使其成为作物改良的理想目标。然而，关于维管形成层如何增殖，仍有许多未知之处。在这项研究中，我们通过药物和遗传手段控制活性氧（ROS）最大值，证明了 ROS 水平与维持维管形成层活性的 LATERAL ORGAN BOUNDARIES DOMAIN 11（LBD11）活性之间存在直接联系。LBD11 激活了几个关键 ROS 代谢基因的转录，包括 PEROXIDASE 71 和 RESPIRATORY BURST OXIDASE HOMOLOGS D 和 F，以在形成层中产生局部 ROS 最大值，从而增强形成层细胞的增殖。在负反馈机制中，较高的 ROS 水平会抑制 LBD11 的表达，从而维持形成层细胞增殖的平衡。因此，我们的研究结果揭示了一种新的 LBD11/ROS 依赖的反馈调节系统在维持植物维管形成层特异性氧化还原平衡和径向生长中的作用。
