Bud dormancy allows deciduous perennial plants to rapidly grow following seasonal cold conditions. Although many studies have examined the hormonal regulation of bud growth, the role of nutrients remains unclear. Insufficient accumulation of the key micronutrient zinc (Zn) in dormant buds affects the vegetative and reproductive growth of perennial plants during the subsequent year, requiring the application of Zn fertilizers in orchard management to avoid growth defects in fruit trees. However, the mechanisms of seasonal Zn homeostasis in perennial plants remain poorly understood. Here, we provide new insights into Zn distribution and speciation within reproductive and vegetative buds of apple (Malus domestica) and four other deciduous fruit trees (peach [Amygdalus persica], grape [Vitis vinifera], pistachio [Pistacia vera], and blueberry [Vaccinium spp.]) using microscopic and spectroscopic characterization techniques comprising synchrotron-based x-ray fluorescence and x-ray absorption near-edge-structure analyses. By establishing a link between bud development and Zn distribution, we identified the following important steps of Zn storage and use in deciduous plants: Zn is preferentially deposited in the stem nodes subtending apical and axillary buds; Zn may then be sequestered as Zn-phytate prior to dormancy; in spring, Zn effectively releases for use during budbreak and subsequent meristematic growth. The mechanisms of Zn homeostasis during the seasonal cycles of plant growth and dormancy described here will contribute to improving orchard management, and to selection and breeding of deciduous perennial species.

芽休眠可使落叶多年生植物在季节性寒冷条件下迅速生长。尽管许多研究检查了激素对芽生长的调节，但营养素的作用仍不清楚。休眠芽中关键微量营养元素锌（Zn）的积累不足会影响多年生植物的营养和生殖生长，因此需要在果园管理中使用锌肥以避免果树的生长缺陷。然而，多年生植物中季节性锌稳态的机制仍知之甚少。在这里，我们提供了有关苹果（Maus domestica）和其他四种落叶果树（桃[ Amygdalus persica ]，葡萄[葡萄[ Vitis vinifera ]，开心果[ Pistacia vera ]和蓝莓[ Vaccinium]spp。]），使用包括基于同步加速器的X射线荧光和X射线吸收近边缘结构分析在内的显微和光谱表征技术。通过建立芽发育与锌分布之间的联系，我们确定了锌在落叶植物中的存储和使用的重要步骤：锌优先沉积在茎尖和腋芽的茎节中。然后在休眠之前将锌螯合为植酸锌。在春季，锌有效释放，用于芽期和随后的分生生长。本文所述的植物生长和休眠的季节性周期中锌稳态的机制将有助于改善果园管理，并有助于多年生落叶树种的选择和育种。