The extended plant immune system reframes immunity as a host–microbiome network sculpted by root exudates, yet two dimensions remain insufficiently integrated: the ecological rules translating recruited communities into systemic immune output, and the mechanisms by which holobiont state may carry over across generations.扩展的植物免疫系统将免疫重新定义为一个由根系分泌物塑造的宿主-微生物组网络，但有两个维度尚未被充分整合：将招募的群落转化为系统性免疫输出的生态规则，以及全生物体状态跨世代传递的机制。

摘要

（1）Classical pattern-triggered (PTI) and effector-triggered (ETI) immunity, developed in single-pathogen systems, illuminates how plants recognise molecular threats but cannot fully explain immune homeostasis within the dynamic microbial communities plants encounter in nature.经典的模式触发免疫和效应子触发免疫是在单一病原菌系统中发展而来的，它们阐明了植物如何识别分子威胁，但无法完全解释植物在自然界中面对动态微生物群落时的免疫稳态。

（2）The extended plant immune system reframes immunity as a host–microbiome network sculpted by root exudates, yet two dimensions remain insufficiently integrated: the ecological rules translating recruited communities into systemic immune output, and the mechanisms by which holobiont state may carry over across generations.扩展的植物免疫系统将免疫重新定义为一个由根系分泌物塑造的宿主-微生物组网络，但有两个维度尚未被充分整合：将招募的群落转化为系统性免疫输出的生态规则，以及全生物体状态跨世代传递的机制。

（3）We propose that plant immune homeostasis is best analyzed as a three-node feedback circuit that we hypothesize closes across generations.我们提出，植物免疫稳态最好被分析为一个三节点反馈回路，我们假设该回路在世代间形成闭环。

（4）Node 1 (molecular recruitment) integrates root exudate–mediated cross-kingdom signalling, in which primary and secondary metabolites jointly serve nutritional and immune-informative roles.节点1（分子招募）整合了根系分泌物介导的跨界信号传导，其中初生代谢物和次生代谢物共同发挥营养供给和免疫信息传递的双重作用。

（5）Node 2 (ecological translation) is governed by dispersal, immune filtering, drift, priority effects, and functional redundancy, which together determine whether recruitment signals translate into immune buffering.节点2（生态转译）由扩散、免疫过滤、漂变、优先效应和功能冗余共同调控，这些过程共同决定了招募信号是否能转化为免疫缓冲效应。

（6）Node 3 (intergenerational carry-over) comprises three mechanistically distinct routes—epigenetic reprogramming, seed microbiota transmission, and soil legacy—that range from provisionally established to largely hypothetical and whose field-scale validation remains limited.节点3（跨世代传递）包含三种机制上不同的途径——表观遗传重编程、种子微生物群传递和土壤遗留效应——它们从初步确立到很大程度上仍属假设，且其田间尺度的验证仍然有限。

（7）Treating this circuit, rather than the host or host–microbiome network, as the minimal unit of immune analysis generates testable predictions—linking functional redundancy to immune buffering, soil legacy to next-generation priming, and node-specific failure modes to dissociable signatures.将这一回路（而非宿主或宿主-微生物组网络）视为免疫分析的最小单元，可产生可验证的预测——将功能冗余与免疫缓冲联系起来，将土壤遗留与下一代启动效应联系起来，并将节点特异性失效模式与可分离的特征标志联系起来。

（8）This framing positions the holobiont across time (understood here as an analytical unit rather than an evolutionary one) as a tractable framework for hypothesis-driven plant immunity research.这一框架将跨时间的全生物体（在此理解为分析单元而非进化单元）定位为一个便于假设驱动的植物免疫研究的可行框架。

（9）Result

（10） From classical immunity to a three-node holobiont feedback circuit从经典免疫到三节点全生物体反馈回路

总结了植物免疫研究三个框架的演进：经典PTI/ETI在细胞水平揭示了“如何认敌”；扩展植物免疫系统在个体水平揭示了“如何借力”（招募微生物盟友）；三节点全生物体框架则在跨世代水平提出了“如何传承经验”（招募→组装→传递→重置）。新框架的三个核心预测——功能冗余缓冲免疫、土壤遗留量化启动、连作障碍累加崩溃——均可通过实验验证。

（11） Node 1—Molecular recruitment and the host's systemic immune-signalling program 节点1——分子招募与宿主的系统性免疫信号程序

（12） Node 2—Community assembly and its translation into immune buffering 节点2——群落组装及其向免疫缓冲的转译

植物根部的有益微生物如何通过信号传递，让整株植物（包括叶片）进入防御状态？而地上产生的防御信号又是如何反馈回根部，调控微生物群落的？

（13） Node 3—Intergenerational carry-over and the hypothesized closure of the feedback circuit 节点3——跨世代传递与反馈回路的假设性闭合

表3 微生物组介导的跨世代传递代表性证据

上一代植物经历过的“免疫经验”，到底能不能传给下一代？如果能，是通过什么方式传的？证据有多强？

（1）Node 1 (molecular recruitment) integrates root exudate–mediated cross-kingdom signalling, in which primary and secondary metabolites jointly serve nutritional and immune-informative roles.节点1（分子招募）整合了根系分泌物介导的跨界信号传导，其中初生代谢物和次生代谢物共同发挥营养供给和免疫信息传递的双重作用。

（2）Node 2 (ecological translation) is governed by dispersal, immune filtering, drift, priority effects, and functional redundancy, which together determine whether recruitment signals translate into immune buffering.节点2（生态转译）由扩散、免疫过滤、漂变、优先效应和功能冗余共同调控，这些过程共同决定了招募信号是否能转化为免疫缓冲效应。

（3）Node 3 (intergenerational carry-over) comprises three mechanistically distinct routes—epigenetic reprogramming, seed microbiota transmission, and soil legacy—that range from provisionally established to largely hypothetical and whose field-scale validation remains limited.节点3（跨世代传递）包含三种机制上不同的途径——表观遗传重编程、种子微生物群传递和土壤遗留效应——它们从初步确立到很大程度上仍属假设，且其田间尺度的验证仍然有限。