Induced Systemic Resistance as a Mechanism of Disease Suppression by Rhizobacteria
Induced Systemic Resistance as a Mechanism of Disease Suppression by Rhizobacteria
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DOI：
10.1007/1-4020-4152-7_2
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
L. C. Loon;P. Bakker
中科院分区：
文献类型：
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作者：
L. C. Loon;P. Bakker
促进植物生长的根际细菌可以通过细菌和土传病原体之间的拮抗作用，以及通过诱导植物对根和叶病原体的系统抵抗力来抑制疾病。诱导抗性的一般非特异性特征构成了对多种病原体的基础抗性水平同时增加，这在可能存在多种病原体的自然条件下是有益的。特定的假单胞菌菌株可诱导系统耐药性，例如康乃馨、黄瓜、萝卜、烟草和拟南芥，攻击接种后防御能力增强就证明了这一点。尽管一些细菌菌株在诱导不同植物物种的抗性方面同样有效，但其他菌株则表现出特异性，表明细菌和植物在根部表面存在特异性识别。在康乃馨、萝卜和拟南芥中，细菌外膜脂多糖的 O 抗原侧链充当诱导决定簇，但也涉及其他细菌性状。假杆菌素铁载体与烟草和拟南芥抗性的诱导有关，而另一种铁载体假单胞菌碱可以解释萝卜中与水杨酸（SA）相关的抗性诱导。尽管 SA 诱导表型相似的系统获得性抗性 (SAR)，但它对于大多数根际细菌菌株诱导的系统性抗性来说并不是必需的。相反，根际细菌介导的诱导系统抗性（ISR）依赖于植物中的茉莉酸（JA）和乙烯信号传导。当用病原体攻击接种诱导拟南芥植物时，表达SAR的叶子表现出SA反应性防御相关基因的引发表达，但不表现出JA/乙烯反应性防御相关基因，而表达ISR的叶子则表现出引发表达JA/乙烯反应性基因，但不表达SA反应性基因。 ISR 和 SAR 的组合可以增强对通过这两种途径抵抗的病原体的保护，并且可以将保护范围扩展到比单独使用 ISR 或 SAR 更广泛的病原体。
Plant growth-promoting rhizobacteria can suppress diseases through antagonism between the bacteria and soil-borne pathogens, as well as by inducing a systemic resistance in the plant against both root and foliar pathogens. The generally non-specific character of induced resistance constitutes an increase in the level of basal resistance to several pathogens simultaneously, which is of benefit under natural conditions where multiple pathogens may be present. SpecificPseudomonasstrains induce systemic resistance in e.g. carnation, cucumber, radish, tobacco andArabidopsis, as evidenced by an enhanced defensive capacity upon challenge inoculation. Although some bacterial strains are equally effective in inducing resistance in different plant species, others show specificity, indicating specific recognition between bacteria and plants at the root surface. In carnation, radish andArabidopsis, the O-antigenic side chain of the bacterial outer membrane lipopolysaccharide acts as an inducing determinant, but other bacterial traits are also involved. Pseudobactin siderophores have been implicated in the induction of resistance in tobacco andArabidopsis, and another siderophore, pseudomonine, may explain induction of resistance associated with salicylic acid (SA) in radish. Although SA induces phenotypically similar systemic acquired resistance (SAR), it is not necessary for the systemic resistance induced by most rhizobacterial strains. Instead, rhizobacteria-mediated induced systemic resistance (ISR) is dependent on jasmonic acid (JA) and ethylene signaling in the plant. Upon challenge inoculation of inducedArabidopsisplants with a pathogen, leaves expressing SAR exhibit a primed expression of SA-, but not JA/ethylene-responsive defense-related genes, whereas leaves expressing ISR are primed to express JA/ethylene-, but not SA-responsive genes. Combination of ISR and SAR can increase protection against pathogens that are resisted through both pathways, as well as extend protection to a broader spectrum of pathogens than ISR or SAR alone.