Cortleven Anne, Roeber Venja M, Frank Manuel, Bertels Jonas, Lortzing Vivien, Beemster Gerrit T S, Schmülling Thomas
Dahlem Centre of Plant Sciences, Institute of Biology/Applied Genetics, Freie Universität Berlin, Berlin, Germany.
Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark.
Front Plant Sci. 2022 May 12;13:838284. doi: 10.3389/fpls.2022.838284. eCollection 2022.
Plants are exposed to regular diurnal rhythms of light and dark. Changes in the photoperiod by the prolongation of the light period cause photoperiod stress in short day-adapted . Here, we report on the transcriptional response to photoperiod stress of wild-type and photoperiod stress-sensitive cytokinin signaling and clock mutants and identify a core set of photoperiod stress-responsive genes. Photoperiod stress caused altered expression of numerous reactive oxygen species (ROS)-related genes. Photoperiod stress-sensitive mutants displayed similar, but stronger transcriptomic changes than wild-type plants. The alterations showed a strong overlap with those occurring in response to ozone stress, pathogen attack and flagellin peptide (flg22)-induced PAMP triggered immunity (PTI), which have in common the induction of an apoplastic oxidative burst. Interestingly, photoperiod stress triggers transcriptional changes in jasmonic acid (JA) and salicylic acid (SA) biosynthesis and signaling and results in increased JA, SA and camalexin levels. These responses are typically observed after pathogen infections. Consequently, photoperiod stress increased the resistance of plants to a subsequent infection by pv. DC3000. In summary, we show that photoperiod stress causes transcriptional reprogramming resembling plant pathogen defense responses and induces systemic acquired resistance (SAR) in the absence of a pathogen.
植物会受到有规律的昼夜光照节律影响。通过延长光照时长改变光周期会在适应短日照的植物中引发光周期胁迫。在此，我们报告了野生型以及光周期胁迫敏感型细胞分裂素信号传导和生物钟突变体对光周期胁迫的转录反应，并鉴定出一组核心的光周期胁迫响应基因。光周期胁迫导致众多活性氧（ROS）相关基因的表达发生改变。光周期胁迫敏感型突变体表现出与野生型植物相似但更强的转录组变化。这些变化与因臭氧胁迫、病原体攻击以及鞭毛蛋白肽（flg22）诱导的病原体相关分子模式触发的免疫反应（PTI）所发生的变化有很大重叠，这些反应的共同之处在于诱导质外体氧化爆发。有趣的是，光周期胁迫会触发茉莉酸（JA）和水杨酸（SA）生物合成及信号传导的转录变化，并导致JA、SA和camalexin水平升高。这些反应通常在病原体感染后观察到。因此，光周期胁迫增强了植物对丁香假单胞菌番茄致病变种（Pseudomonas syringae pv. tomato）DC3000后续感染的抗性。总之，我们表明光周期胁迫会导致转录重编程，类似于植物病原体防御反应，并在没有病原体的情况下诱导系统获得性抗性（SAR）。
