Department of Biological Sciences and BioDiscovery Institute, University of North Texas, Denton, TX 76203-5017, USA.
Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, Biotecnología Vegetal, subsede Sureste, 97302 Mérida, México.
Plant Physiol. 2023 May 31;192(2):1517-1531. doi: 10.1093/plphys/kiad126.
Meristem maintenance, achieved through the highly conserved CLAVATA-WUSCHEL (CLV-WUS) regulatory circuit, is fundamental in balancing stem cell proliferation with cellular differentiation. Disruptions to meristem homeostasis can alter meristem size, leading to enlarged organs. Cotton (Gossypium spp.), the world's most important fiber crop, shows inherent variation in fruit size, presenting opportunities to explore the networks regulating meristem homeostasis and to impact fruit size and crop value. We identified and characterized the cotton orthologs of genes functioning in the CLV-WUS circuit. Using virus-based gene manipulation in cotton, we altered the expression of each gene to perturb meristem regulation and increase fruit size. Targeted alteration of individual components of the CLV-WUS circuit modestly fasciated flowers and fruits. Unexpectedly, controlled expression of meristem regulator SELF-PRUNING (SP) increased the impacts of altered CLV-WUS expression on flower and fruit fasciation. Meristem transcriptomics showed SP and genes of the CLV-WUS circuit are expressed independently from each other, suggesting these gene products are not acting in the same path. Virus-induced silencing of GhSP facilitated the delivery of other signals to the meristem to alter organ specification. SP has a role in cotton meristem homeostasis, and changes in GhSP expression increased access of virus-derived signals to the meristem.
顶端分生组织的维持是通过高度保守的 CLAVATA-WUSCHEL（CLV-WUS）调控回路实现的，这对于平衡干细胞增殖和细胞分化至关重要。顶端分生组织稳态的破坏会改变顶端分生组织的大小，导致器官增大。棉花（Gossypium spp.）是世界上最重要的纤维作物，其果实大小存在固有变异，为探索调控顶端分生组织稳态的网络以及影响果实大小和作物价值提供了机会。我们鉴定并描述了在 CLV-WUS 回路中发挥作用的棉花同源基因。我们通过在棉花中使用基于病毒的基因操作，改变每个基因的表达以扰乱顶端分生组织的调控并增加果实大小。对 CLV-WUS 回路单个组成部分的靶向改变适度地使花朵和果实出现联生性。出乎意料的是，对顶端分生组织调节因子自剪枝（SELF-PRUNING，SP）的控制表达增加了改变 CLV-WUS 表达对花和果实联生性的影响。顶端分生组织转录组学显示 SP 和 CLV-WUS 回路的基因彼此独立表达，表明这些基因产物并非在同一途径中发挥作用。GhSP 的病毒诱导沉默促进了其他信号传递到顶端分生组织以改变器官特征。SP 在棉花顶端分生组织稳态中起作用，并且 GhSP 表达的改变增加了病毒衍生信号进入顶端分生组织的机会。
