水稻免疫的双磷酸化开关：自然通讯研究称 OsPUB2 降解 OsPUB12，两处磷酸化方向相反
自然通讯期刊 11 月 11 日发表一项水稻免疫研究，作者为赵等人。论文于 2026 年 2 月 4 日投稿，10 月 10 日接受，数字对象标识符为 10.1038/s41467-026-79063-x。
研究揭示，泛素 E3 连接酶 OsPUB2 能特异地与 OsPUB12 相互作用，并将其送入泛素介导的降解途径。与 OsPUB12 抑制免疫的作用相反，OsPUB2 正向调控水稻对细菌性病害的抗性，并参与病原相关分子模式诱导的活性氧爆发与防御基因表达。
病原侵袭时，钙依赖激酶 OsCPK17 与丝裂原活化蛋白激酶 OsMPK6 按时间顺序先后磷酸化 OsPUB12 的两个位点：第 154 位苏氨酸与第 460 位丝氨酸。
论文称，这两次磷酸化对 OsPUB12 与 OsPUB2 的相互作用及其后续泛素化产生方向相反的调控，进而对 OsPUB12 的稳定性与水稻免疫产生分化影响。
作者表示，两种免疫相关激酶对 OsPUB12 的不同磷酸化协同维持了 OsPUB2 介导的 OsPUB12 稳态平衡，构成精细调节水稻免疫的核心机制。
A Dual Phosphorylation Switch Balances Rice Immunity: Nature Communications Study Shows OsPUB2 Degrades OsPUB12
A rice immunity study by Zhao and colleagues was published in Nature Communications on November 11. The paper was received on February 4, 2026 and accepted on October 10, 2026, with digital object identifier 10.1038/s41467-026-79063-x.
The study reveals that the ubiquitin E3 ligase OsPUB2 specifically interacts with OsPUB12 and targets it for ubiquitin-mediated degradation. In contrast to the immunity-suppressing role of OsPUB12, OsPUB2 positively regulates resistance to rice bacterial diseases and contributes to pathogen-associated molecular pattern induced reactive oxygen burst and defense gene expression.
Upon pathogen challenge, the calcium-dependent kinase OsCPK17 and the mitogen-activated protein kinase OsMPK6 phosphorylate OsPUB12 at threonine 154 and serine 460 in a temporally sequential manner.
These two phosphorylation events oppositely regulate the interaction of OsPUB12 with OsPUB2 and its subsequent ubiquitination, leading to divergent regulation of OsPUB12 stability and rice immunity, the paper said.
The authors said the distinct phosphorylation of OsPUB12 by the two immune-related kinases synergistically maintains OsPUB2-mediated OsPUB12 homeostasis, serving as a core mechanism to fine-tune rice immunity.
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图片来源：图：稻田里正在成熟的水稻植株与金黄稻穗特写。Undeka 11 摄，CC BY-SA 4.0，经 Wikimedia Commons / Photo: Ripening rice plants in paddy field, Indonesia. By Undeka 11, CC BY-SA 4.0, via Wikimedia Commons
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