Gai Weiling, Liu Chunying, Yang Mengjie, Li Feng, Xin Hua, Gai Shupeng
College of Agriculture, Qingdao Agricultural University, Qingdao, China.
University Key Laboratory of Plant Biotechnology in Shandong Province, Qingdao, China.
Front Plant Sci. 2024 Mar 19;15:1362804. doi: 10.3389/fpls.2024.1362804. eCollection 2024.
Calcium plays a crucial role in plant growth and development, yet little is known about its function in endodormancy regulation. Tree peony (), characterized by compound buds and large flowers, is well-known for its ornamental and medicinal value. To break bud dormancy release is a prerequisite of flowering and forcing culture, particularly during the Spring Festival. In this study, the Ca chelator EGTA and Ca channel blocker LaCl were applied, resulting in a significant delay in budburst during both chilling- and gibberellin (GA)- induced dormancy release in a dosage-dependent manner. As expected, the retardation of bud break was recovered by the supplementation of 30 mM CaCl, indicating a facilitating role of calcium in dormancy release. Accordingly, several calcium-sensor-encoding genes including () and (s) were significantly up-regulated by prolonged chilling and exogenous GAs. Ultrastructure observations revealed a decline in starch grains and the reopening of transport corridors following prolonged chilling. Calcium deposits were abundant in the cell walls and intercellular spaces at the early dormant stage but were enriched in the cytosol and nucleus before dormancy release. Additionally, several genes associated with dormancy release, including , , , , , , and , were differentially expressed after calcium blocking and recovery treatments, indicating that calcium might partially modulate dormancy release through GA and ABA pathways. Our findings provide novel insights into the mechanism of dormancy release and offer potential benefits for improving and perfecting forcing culture technology in tree peonies.
钙在植物生长发育中起着至关重要的作用，但其在芽内休眠调控中的功能却鲜为人知。牡丹以其复合芽和大花为特征，具有很高的观赏和药用价值。打破芽休眠是开花和促成栽培的前提条件，尤其是在春节期间。在本研究中，应用了钙螯合剂乙二醇双（2-氨基乙基醚）四乙酸（EGTA）和钙通道阻滞剂氯化镧（LaCl），结果导致在低温和赤霉素（GA）诱导的休眠解除过程中，芽萌发显著延迟，且呈剂量依赖性。正如预期的那样，补充30 mM氯化钙可恢复芽萌发的延迟，表明钙在休眠解除中起促进作用。相应地，包括（相关基因名称未给出）和（相关基因名称未给出）在内的几个钙传感器编码基因在长时间低温和外源GA处理下显著上调。超微结构观察显示，长时间低温处理后淀粉粒减少，运输通道重新开放。在休眠早期，细胞壁和细胞间隙中钙沉积丰富，但在休眠解除前钙在细胞质和细胞核中富集。此外，包括（相关基因名称未给出）、（相关基因名称未给出）、（相关基因名称未给出）、（相关基因名称未给出）、（相关基因名称未给出）、（相关基因名称未给出）和（相关基因名称未给出）在内的几个与休眠解除相关的基因在钙阻断和恢复处理后差异表达，表明钙可能通过GA和脱落酸（ABA）途径部分调节休眠解除。我们的研究结果为休眠解除机制提供了新的见解，并为改进和完善牡丹促成栽培技术提供了潜在的益处。
