Kwaśniewska Kamila, Breathnach Caoilfhionn, Fitzsimons Christina, Goslin Kevin, Thomson Bennett, Beegan Joseph, Finocchio Andrea, Prunet Nathanaël, Ó'Maoiléidigh Diarmuid S, Wellmer Frank
Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland.
Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, United States.
Front Plant Sci. 2021 Jul 21;12:704351. doi: 10.3389/fpls.2021.704351. eCollection 2021.
In the model plant , the zinc-finger transcription factor KNUCKLES (KNU) plays an important role in the termination of floral meristem activity, a process that is crucial for preventing the overgrowth of flowers. The gene is activated in floral meristems by the floral organ identity factor AGAMOUS (AG), and it has been shown that both AG and KNU act in floral meristem control by directly repressing the stem cell regulator (), which leads to a loss of stem cell activity. When we re-examined the expression pattern of in floral meristems, we found that is expressed throughout the center of floral meristems, which includes, but is considerably broader than the expression domain. We therefore hypothesized that KNU may have additional functions in the control of floral meristem activity. To test this, we employed a gene perturbation approach and knocked down activity at different times and in different domains of the floral meristem. In these experiments we found that early expression in the stem cell domain, which is characterized by the expression of the key meristem regulatory gene (), is crucial for the establishment of expression. The results of additional genetic and molecular analyses suggest that KNU represses floral meristem activity to a large extent by acting on . Thus, KNU might need to suppress the expression of several meristem regulators to terminate floral meristem activity efficiently.
在模式植物中，锌指转录因子KNUCKLES（KNU）在花分生组织活性的终止过程中发挥重要作用，这一过程对于防止花的过度生长至关重要。该基因在花分生组织中由花器官特征因子AGAMOUS（AG）激活，并且已经表明AG和KNU都通过直接抑制干细胞调节因子（）来控制花分生组织，这导致干细胞活性丧失。当我们重新检查（此处原文缺失相关基因名）在花分生组织中的表达模式时，我们发现（该基因）在花分生组织的整个中心区域表达，其中包括但明显比（另一基因）的表达域更宽。因此，我们推测KNU可能在控制花分生组织活性方面具有额外功能。为了验证这一点，我们采用了基因干扰方法，并在花分生组织的不同时间和不同区域敲低（该基因）活性。在这些实验中，我们发现在以关键分生组织调节基因（此处原文缺失相关基因名）表达为特征的干细胞区域中的早期表达，对于（另一基因）表达的建立至关重要。额外的遗传和分子分析结果表明，KNU在很大程度上通过作用于（此处原文缺失相关基因名）来抑制花分生组织活性。因此，KNU可能需要抑制几种分生组织调节因子的表达，以有效地终止花分生组织活性。
