Magnesium oxide induces immunity against Fusarium wilt by triggering the jasmonic acid signaling pathway in tomato
Magnesium oxide induces immunity against Fusarium wilt by triggering the jasmonic acid signaling pathway in tomato
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DOI：
10.1016/j.jbiotec.2020.11.012
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发表时间：
2021-01-10
影响因子：
4.1
通讯作者：
Ito, Shin-ichi
中科院分区：
文献类型：
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作者：
Fujikawa, Isamu;Takehara, Yushi;Ito, Shin-ichi
由尖孢镰刀菌番茄专化型（FOL）引起的枯萎病是一种全球性的番茄病害。尽管枯萎病的防治仍未取得成功，但利用氧化镁激活植物免疫来增强宿主对FOL的抗性可能实现有效控制。我们证明了根部经氧化镁预处理可诱导感病番茄植株对FOL产生抗性。在茉莉酸（JA）信号通路缺陷的番茄突变体中未诱导出抗性，而在水杨酸和乙烯信号通路缺陷的突变体中观察到相反的趋势，这表明JA信号激活对于氧化镁诱导的对FOL的免疫至关重要。对经氧化镁预处理并接种FOL的番茄植株进行实时定量聚合酶链反应分析表明，JA信号的主要调控因子髓细胞瘤致癌基因同源物2（MYC2）以及直接调控JA诱导的晚期防御基因及其下游创伤应答基因转录的MYC2靶向转录因子在根和茎中均优先上调。此外，在经氧化镁预处理并接种FOL的番茄植株中，晚期创伤应答的苏氨酸脱氨酶2（TD）基因比其上游基因（包括MYC2）更早表达，这表明在经氧化镁预处理的植株中建立了一种防御的预备状态。我们得出结论，氧化镁是一种有前景的防治枯萎病的药剂。
Fusarium wilt, caused by Fusarium oxysporum f. sp. lycopersici (FOL), is a worldwide tomato disease. Although Fusarium wilt management remains unsuccessful, enhancing host FOL resistance using magnesium oxide to activate plant immunity may enable effective control. We demonstrated that MgO-pretreatment of roots induced FOL resistance in susceptible tomato plants. Resistance was not induced in tomato mutants deficient in the jasmonic acid (JA) signaling pathway, whereas the opposite trend was observed in mutants deficient in the salicylic acid and ethylene signaling pathways, suggesting that JA signaling activation is essential for MgO-induced FOL immunity. Quantitative real-time polymerase chain reaction analysis of MgO-pretreated tomato plants, and challenge-inoculated with FOL, revealed that MYELOCYTOMATOSIS ONCOGENE HOMOLOG 2 (MYC2), the master regulator of JA signaling, as well as MYC2-targeted transcription factors that directly regulate the JA-induced transcription of late defense genes and their downstream wound-responsive genes were preferentially upregulated in both roots and stems. Moreover, in MgO-pretreated tomato plants challenge-inoculated with FOL, the late wound-responsive THREONINE DEAMINASE 2 (TD) gene was expressed earlier than its upstream genes, including MYC2, suggesting that a primed state for defense was established in MgO-pretreated plants. We conclude that MgO is a promising agent for the control of Fusarium wilt.