Périlleux Claire, Huerga-Fernández Samuel
Laboratory of Plant Physiology, Research Unit InBioS-PhytoSYSTEMS, Institute of Botany B22 Sart Tilman, University of Liège, Liège, Belgium.
Front Plant Sci. 2022 Feb 8;13:798502. doi: 10.3389/fpls.2022.798502. eCollection 2022.
Branching is an important component determining crop yield. In tomato, the sympodial pattern of shoot and inflorescence branching is initiated at floral transition and involves the precise regulation of three very close meristems: (i) the shoot apical meristem (SAM) that undergoes the first transition to flower meristem (FM) fate, (ii) the inflorescence sympodial meristem (SIM) that emerges on its flank and remains transiently indeterminate to continue flower initiation, and (iii) the shoot sympodial meristem (SYM), which is initiated at the axil of the youngest leaf primordium and takes over shoot growth before forming itself the next inflorescence. The proper fate of each type of meristems involves the spatiotemporal regulation of FM genes, since they all eventually terminate in a flower, but also the transient repression of other fates since conversions are observed in different mutants. In this paper, we summarize the current knowledge about the genetic determinants of meristem fate in tomato and share the reflections that led us to identify sepal and flower abscission zone initiation as a critical stage of FM development that affects the branching of the inflorescence.
分枝是决定作物产量的一个重要组成部分。在番茄中，茎和花序分枝的合轴模式在花期转换时启动，涉及对三个非常接近的分生组织的精确调控：（i）经历首次向花分生组织（FM）命运转变的茎尖分生组织（SAM）；（ii）出现在其侧面并暂时保持不确定状态以继续花起始的花序合轴分生组织（SIM）；以及（iii）在最幼嫩叶原基的叶腋处起始并在形成下一个花序之前接管茎生长的茎合轴分生组织（SYM）。每种类型分生组织的正确命运涉及FM基因的时空调控，因为它们最终都发育成一朵花，但由于在不同突变体中观察到了转变，所以也涉及对其他命运的暂时抑制。在本文中，我们总结了目前关于番茄分生组织命运的遗传决定因素的知识，并分享了促使我们将萼片和花脱落区起始确定为影响花序分枝的FM发育关键阶段的思考。
