Seo Shigemi, Nakaho Kazuhiro, Hong Si Won, Takahashi Hideki, Shigemori Hideyuki, Mitsuhara Ichiro
Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, 305-8602 Japan
Central Region Agricultural Research Center, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, 305-8666 Japan
Plant Cell Physiol. 2016 Sep;57(9):1932-42. doi: 10.1093/pcp/pcw114. Epub 2016 Jun 22.
Wilt disease in plants, which is caused by the soil-borne bacterial pathogen Ralstonia solanacearum, is one of the most devastating plant diseases. We previously detected bacterial wilt disease-inhibiting activity in an extract from yeast cells. In the present study, we purified this activity and identified one of the substances responsible for the activity as the amino acid histidine. The exogenous application of l-histidine, but not d-histidine, inhibited wilt disease in tomato and Arabidopsis plants without exhibiting any antibacterial activity. l-Histidine induced the expression of genes related to ethylene (ET) biosynthesis and signaling as well as the production of ET in tomato and Arabidopsis plants. l-Histidine-induced resistance to R. solanacearum was partially abolished in ein3-1, an ET-insensitive Arabidopsis mutant line. Resistance to the fungal pathogen Botrytis cinerea, which is known to require ET biosynthesis or signaling, was also induced by exogenously applied l-histidine. These results suggest that l-histidine induces resistance to R. solanacearum and B. cinerea partially through the activation of ET signaling in plants.
由土壤传播的细菌病原体青枯雷尔氏菌引起的植物青枯病，是最具毁灭性的植物病害之一。我们之前在酵母细胞提取物中检测到了抑制青枯病的活性。在本研究中，我们纯化了这种活性，并鉴定出负责该活性的物质之一为氨基酸组氨酸。外源施用L-组氨酸而非D-组氨酸可抑制番茄和拟南芥植株的青枯病，且未表现出任何抗菌活性。L-组氨酸诱导了番茄和拟南芥植株中与乙烯（ET）生物合成和信号传导相关的基因表达以及ET的产生。在ET不敏感的拟南芥突变系ein3-1中，L-组氨酸诱导的对青枯雷尔氏菌的抗性部分丧失。外源施用L-组氨酸也诱导了对已知需要ET生物合成或信号传导的真菌病原体灰葡萄孢的抗性。这些结果表明，L-组氨酸部分通过激活植物中的ET信号传导来诱导对青枯雷尔氏菌和灰葡萄孢的抗性。
