Sweet osmanthus (), an evergreen tree species known for its captivating floral scent, is used extensively in both the landscape and fragrance industries. However, poor growth and reduced ornamental value caused by cold stress create a bottleneck in the wide-scale application of . Cold acclimation is an effective mechanism used by plants in response to cold stress. In this study, we integrated physiological, hormonal, and transcriptional changes to determine the molecular regulation underlying chilling-induced cold acclimation in . We found that 5 days of chilling stress can trigger cold acclimation and enhance the freeze tolerance of 2-year-old sweet osmanthus cuttings. Cold acclimatized regulation of phytohormone abscisic acid (ABA), and plasma membrane damage indicated by relative electrical conductivity (REC), were the most responsive factors in the chilling-induced cold acclimation of . Weighted gene correlation network analysis indicated that the ABA and REC changes were most associated with a module containing 12 hub E3 ubiquitin ligase genes that potentially participated in the ABA-mediated chilling-induced cold acclimation. Interestingly, a nuclear-localized E3 ubiquitin ligase hub gene, , was suppressed by exogenous ABA treatment. We found that the transient overexpression of increased cold hypersensitivity in tobacco and sweet osmanthus by suppressing ABA-mediated responses. These findings provide a framework for understanding the participation of E3 ubiquitination in ABA-mediated cold acclimation under chilling stress and generate a valuable resource for the breeding of cold hardiness in .

中文翻译：

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综合生理、激素和转录组分析揭示了一种新的 E3 泛素连接酶介导的冷驯化机制，用于桂花获得耐冷性


桂花是一种常绿树种，以其迷人的花香而闻名，广泛用于景观和香料行业。然而，低温胁迫导致的生长不良和观赏价值降低，成为其大规模应用的瓶颈。冷驯化是植物应对冷胁迫的有效机制。在这项研究中，我们整合了生理、激素和转录变化，以确定寒冷诱导的冷驯化背后的分子调控。我们发现5天的寒冷胁迫可以引发冷驯化，增强2年生桂花插条的抗冻能力。植物激素脱落酸（ABA）的冷驯化调节和相对电导率（REC）表明的质膜损伤是冷驯化中最敏感的因素。加权基因相关网络分析表明，ABA 和 REC 的变化与包含 12 个中心 E3 泛素连接酶基因的模块最相关，该模块可能参与 ABA 介导的寒冷诱导的冷驯化。有趣的是，核定位的 E3 泛素连接酶中心基因 被外源 ABA 处理抑制。我们发现烟草和桂花通过抑制 ABA 介导的反应而短暂过度表达，从而增加了冷过敏反应。这些发现为理解 E3 泛素化在寒冷胁迫下 ABA 介导的冷驯化中的参与提供了一个框架，并为抗寒育种提供了宝贵的资源。