State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and National Center for Plant Gene Research, Beijing 100101, China
State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and National Center for Plant Gene Research, Beijing 100101, China.
Development. 2018 Dec 10;145(24):dev158352. doi: 10.1242/dev.158352.
Branching is a common feature of plant development. In seed plants, axillary meristems (AMs) initiate in leaf axils to enable lateral shoot branching. AM initiation requires a high level of expression of the meristem marker () in the leaf axil. Here, we show that modules of interacting transcriptional regulators control expression and AM initiation. Two redundant AP2-type transcription factors, () and (), control AM initiation by regulating expression. DRN and DRNL directly upregulate expression in leaf axil meristematic cells, as does another transcription factor, REVOLUTA (REV). The activation of expression by DRN/DRNL depends on REV, and vice versa. DRN/DRNL and REV have overlapping expression patterns and protein interactions in the leaf axil, which are required for the upregulation of expression. Furthermore, LITTLE ZIPPER3, another REV-interacting protein, is expressed in the leaf axil and interferes with the DRN/DRNL-REV interaction to negatively modulate expression. Our results support a model in which interacting transcriptional regulators fine-tune the expression of to precisely regulate AM initiation. Thus, shoot branching recruits the same conserved protein complexes used in embryogenesis and leaf polarity patterning.
分枝是植物发育的一个共同特征。在种子植物中，腋芽分生组织（AMs）在叶腋处起始，以实现侧枝分枝。AM 的起始需要在叶腋处高水平表达分生组织标记物 ()。在这里，我们表明相互作用的转录调节因子模块控制表达和 AM 的起始。两个冗余的 AP2 型转录因子 () 和 ()（）通过调节表达来控制 AM 的起始。DRN 和 DRNL 直接在上部叶腋分生组织细胞中上调的表达，另一个转录因子 REVOLUTA（REV）也是如此。DRN/DRNL 对表达的激活依赖于 REV，反之亦然。DRN/DRNL 和 REV 在叶腋处具有重叠的表达模式和蛋白相互作用，这是上调表达所必需的。此外，另一个与 REV 相互作用的蛋白质 LITTLE ZIPPER3 也在叶腋中表达，并干扰 DRN/DRNL-REV 相互作用，从而负调控表达。我们的结果支持这样一个模型，即相互作用的转录调节因子精细调控的表达，以精确调节 AM 的起始。因此，分枝招募了在胚胎发生和叶片极性模式形成中使用的相同保守蛋白复合物。
