Induction of systemic stress tolerance by brassinosteroid in Cucumis sativus.
Induction of systemic stress tolerance by brassinosteroid in Cucumis sativus.
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DOI：
10.1111/j.1469-8137.2011.03745.x
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发表时间：
2011-08
期刊：
影响因子：
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通讯作者：
X. Xia;Yanhong Zhou;J. Ding;K. Shi;T. Asami;Zhixiang Chen;Jingquan Yu
中科院分区：
文献类型：
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作者：
X. Xia;Yanhong Zhou;J. Ding;K. Shi;T. Asami;Zhixiang Chen;Jingquan Yu
类甾醇（BR）是一类新的植物激素，对植物生长和发育至关重要。在这里，BR参与植物系统耐受生物和非生物胁迫进行了研究。通过叶绿素荧光成像脉冲幅度调制评估光氧化胁迫症状，使用定量实时PCR分析基因表达以及使用分光光度法或共聚焦激光扫描显微镜测量过氧化氢（H2 O2）的产生来研究24-表油菜素（EBR）对植物耐胁迫性的影响。·用EBR处理初生叶诱导未处理的上部和下部叶对光氧化胁迫的系统耐受性。这是伴随着系统积累的H-2 O-和系统诱导的基因与压力反应。EBR叶面处理也增强了根系对枯萎病菌的抗性。药理学研究表明，EBR诱导的全身耐受依赖于局部和全身的H ↓ [2] O ↓ [3]蓄积。BR生物合成基因的表达在EBR处理的叶片中受到抑制，但在未处理的系统叶片中显著升高。进一步的分析表明，EBR诱导的BR生物合成基因的系统诱导是由系统性升高的H2O介导的。·这些结果有力地证明，局部EBR处理可以激活H2O的连续产生，而活性氧信号的自繁殖性质反过来介导EBR诱导的全身耐受。
• Brassinosteroids (BRs) are a new class of plant hormones that are essential for plant growth and development. Here, the involvement of BRs in plant systemic tolerance to biotic and abiotic stresses was studied. • The effects of 24-epibrassinolide (EBR) on plant stress tolerance were studied through the assessment of symptoms of photooxidative stress by chlorophyll fluorescence imaging pulse amplitude modulation, the analysis of gene expression using quantitative real-time PCR and the measurement of hydrogen peroxide (H₂O₂) production using a spectrophotometric assay or confocal laser scanning microscopy. • Treatment of primary leaves with EBR induced systemic tolerance to photooxidative stress in untreated upper and lower leaves. This was accompanied by the systemic accumulation of H₂O₂ and the systemic induction of genes associated with stress responses. Foliar treatment of EBR also enhanced root resistance to Fusarium wilt pathogen. Pharmacological study showed that EBR-induced systemic tolerance was dependent on local and systemic H₂O₂ accumulation. The expression of BR biosynthetic genes was repressed in EBR-treated leaves, but elevated significantly in untreated systemic leaves. Further analysis indicated that EBR-induced systemic induction of BR biosynthetic genes was mediated by systemically elevated H₂O₂. • These results strongly argue that local EBR treatment can activate the continuous production of H₂O₂, and the autopropagative nature of the reactive oxygen species signal, in turn, mediates EBR-induced systemic tolerance.