Vayssières Alice, Mishra Priyanka, Roggen Adrian, Neumann Ulla, Ljung Karin, Albani Maria C
Institute for Plant Sciences, University of Cologne, Zülpicher Straße 47b, Cologne, 50674, Germany.
Cluster of Excellence on Plant Sciences 'From Complex Traits towards Synthetic Modules', Düsseldorf, 40225, Germany.
New Phytol. 2020 Jul;227(1):99-115. doi: 10.1111/nph.16470. Epub 2020 Mar 12.
Perennials have a complex shoot architecture with axillary meristems organized in zones of differential bud activity and fate. This includes zones of buds maintained dormant for multiple seasons and used as reservoirs for potential growth in case of damage. The shoot of Arabis alpina, a perennial relative of Arabidopsis thaliana, consists of a zone of dormant buds placed between subapical vegetative and basal flowering branches. This shoot architecture is shaped after exposure to prolonged cold, required for flowering. To understand how vernalization ensures the maintenance of dormant buds, we performed physiological and transcriptome studies, followed the spatiotemporal changes of auxin, and generated transgenic plants. Our results demonstrate that the complex shoot architecture in A. alpina is shaped by its flowering behavior, specifically the initiation of inflorescences during cold treatment and rapid flowering after subsequent exposure to growth-promoting conditions. Dormant buds are already formed before cold treatment. However, dormancy in these buds is enhanced during, and stably maintained after, vernalization by a BRC1-dependent mechanism. Post-vernalization, stable maintenance of dormant buds is correlated with increased auxin response, transport, and endogenous indole-3-acetic acid levels in the stem. Here, we provide a functional link between flowering and the maintenance of dormant buds in perennials.
多年生植物具有复杂的茎结构，其腋生分生组织按芽活动和命运不同的区域进行组织。这包括多个季节保持休眠的芽区，这些芽区在受到损伤时可作为潜在生长的储备。高山南芥是拟南芥的多年生近缘种，其茎由位于顶端下营养枝和基部花枝之间的休眠芽区组成。这种茎结构是在经历长时间低温（开花所需）后形成的。为了了解春化作用如何确保休眠芽的维持，我们进行了生理学和转录组学研究，追踪了生长素的时空变化，并培育了转基因植物。我们的结果表明，高山南芥复杂的茎结构是由其开花行为塑造的，特别是在低温处理期间花序的起始以及随后暴露于促进生长条件下后的快速开花。休眠芽在低温处理之前就已形成。然而，这些芽的休眠在春化作用期间通过一种依赖BRC1的机制增强，并在春化作用后稳定维持。春化作用后，休眠芽的稳定维持与茎中生长素反应、运输以及内源吲哚 - 3 - 乙酸水平的增加相关。在这里，我们提供了多年生植物开花与休眠芽维持之间的功能联系。
