Systemic resistance in Arabidopsis induced by biocontrol bacteria is independent of salicylic acid accumulation and pathogenesis-related gene expression
Systemic resistance in Arabidopsis induced by biocontrol bacteria is independent of salicylic acid accumulation and pathogenesis-related gene expression
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DOI：
10.1105/tpc.8.8.1225
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发表时间：
1996-08-01
期刊：
影响因子：
11.6
通讯作者：
vanLoon, LC
中科院分区：
文献类型：
--
作者：
Pieterse, CMJ;vanWees, SCM;vanLoon, LC
系统获得性抗性是植物中一种病原菌诱导的防御机制，其抗性状态依赖于内源水杨酸(SA)的积累，其特征是编码病程相关蛋白(PR)的基因被激活。最近，一些非致病的、根部定植的生防菌也被证明也能触发系统抗性反应。为了研究这种类型的系统抗性的分子基础，我们以番茄尖孢镰刀菌和紫丁香假单胞菌为攻击性病原菌，建立了基于拟南芥的模拟系统。荧光疫霉生防菌WCS417r在根际的定殖引起植物介导的抗性反应，显著减轻了两种侵染病原菌引起的症状，而且荧光疫霉WCS417r处理的植株、不能积累SA的转基因拟南芥NahG植株和野生型植株对荧光疫霉WCS417r诱导的抗性反应都有明显的抑制作用。此外，荧光假单胞菌WCS417r介导的系统抗性与挑战接种前PR mRNAs的积累并不一致，这些结果表明，荧光假单胞菌WCS417r诱导了一条不同于控制经典系统获得性抗性的途径，这一途径导致了一种不依赖SA积累和PR基因表达的系统抗性。
Systemic acquired resistance is a pathogen-inducible defense mechanism in plants, The resistant state is dependent on endogenous accumulation of salicylic acid (SA) and is characterized by the activation of genes encoding pathogenesis-related (PR) proteins, Recently, selected nonpathogenic, root-colonizing biocontrol bacteria have been shown to trigger a systemic resistance response as well, To study the molecular basis underlying this type of systemic resistance, we developed an Arabidopsis-based model system using Fusarium oxysporum f sp raphani and Pseudomonas syringae pv tomato as challenging pathogens, Colonization of the rhizosphere by the biological control strain WCS417r of P. fluorescens resulted in a plant-mediated resistance response that significantly reduced symptoms elicited by both challenging pathogens, Moreover, growth of P. syringae in infected leaves was strongly inhibited in P. fluorescens WCS417r-treated plants, Transgenic Arabidopsis NahG plants, unable to accumulate SA, and wild-type plants were equally responsive to P. fluorescens WCS417r-mediated induction of resistance. Furthermore, P. fluorescens WCS417r-mediated systemic resistance did not coincide with the accumulation of PR mRNAs before challenge inoculation, These results indicate that P. fluorescens WCS417r induces a pathway different from the one that controls classic systemic acquired resistance and that this pathway leads to a form of systemic resistance independent of SA accumulation and PR gene expression.