Ultraviolet-B Irradiation Induces Resistance against Powdery Mildew in Cucumber (Cucumis sativus L.) through a Different Mechanism Than That of Heat Shock-Induced Resistance
Ultraviolet-B Irradiation Induces Resistance against Powdery Mildew in Cucumber (Cucumis sativus L.) through a Different Mechanism Than That of Heat Shock-Induced Resistance
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DOI：
10.3390/agronomy12123011
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发表时间：
2022-12-01
期刊：
影响因子：
3.7
通讯作者：
Sato, Tatsuo
中科院分区：
文献类型：
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作者：
Fardhani, Dinar Mindrati;Kharisma, Agung Dian;Sato, Tatsuo
热激处理（HST）和UV-B辐射可以减少病原菌对作物的侵染。然而，关于UV-B作用机制的资料有限。本文研究了UV-B诱导黄瓜抗白粉病的机理，并与热激诱导的抗病性进行了比较。我们测量了显示疾病症状的叶面积百分比，并检查了治疗组之间防御和热休克相关基因的表达水平。UV-B辐射（强度为5 μ W/cm ~ 2）4 h/d，接菌后，与对照组相比，白粉病的发生减少了21.17%。与诱导系统抗性的HST不同，UV-B辐射诱导黄瓜的局部抗性，如基因表达（Chi 2和ETR 2）的局部变化所示。UV-B处理的植物接种白粉病表现出较高的表达水平的Chi 2，ETR 2，和LOX 6比植物，无论是用UV-B处理或接种。UV-B对系统获得性抗性或热休克转录因子没有重大影响，已知这些因子会受到HST的影响。HST与UV-B组合对黄瓜白粉病的防效有较强的增效作用。我们的研究结果表明，UV-B处理可能通过不同的机制比HST在引发黄瓜抗白粉病感染。
Heat shock treatment (HST) and UV-B irradiation can reduce pathogen infection in crops. However, information on the mechanism of UV-B action is limited. Here, we investigated the mechanism of UV-B-induced resistance against powdery mildew in cucumber and compared it to that of heat-shock-induced resistance. We measured the percentage of leaf area showing disease symptoms and examined the expression levels of defense- and heat-shock-related genes across treatment groups. UV-B irradiation (intensity, 5 mu W/cm(2)) for 4 h/d followed by pathogen inoculation reduced the appearance of powdery mildew by 21.17% compared with the control group. Unlike HST-which induces systemic resistance-UV-B irradiation induced local resistance in cucumber, as indicated by local changes in gene expression (Chi2 and ETR2). UV-B-treated plants inoculated with powdery mildew showed higher expression levels of Chi2, ETR2, and LOX6 than plants that were either treated with UV-B or inoculated. UV-B had no major effects on systemic acquired resistance or heat shock transcription factors, which are known to be affected by HST. Combined HST and UV-B had a strong synergistic effect in reducing powdery mildew in cucumber. Our results indicate that UV-B treatment likely operates through a different mechanism than HST in triggering cucumber resistance against powdery mildew infection.