Background: Rice sheath blight (caused by Rhizoctonia solani ) and tobacco mosaic virus are very important plant diseases, causing a huge loss in global crop production. Paenibacillus kribbensis PS04 is a broad-spectrum biocontrol agent, used for controlling these diseases. Previously, extracellular polysaccharides (EPS) from P. kribbensis PS04 had been purified and their structure was inferred to be fructosan. This study aimed to evaluate the effects of exogenous EPS treatment on plant–pathogen interactions. Results: Plant defense genes such as phenylalanine ammonia-lyase, catalase, chitinase, allene oxide synthase, and PR1a proteins were significantly induced by exogenous EPS treatment. Moreover, subsequent challenge of EPS-pretreated plants with the pathogens ( R. solani or tobacco mosaic virus) resulted in higher expression of defense-associated genes. Increased activities of defense-associated enzymes, total phenols, and flavonoids were also observed in EPS pretreated plants. The contents of malondialdehyde in plants, which act as indicator of lipid peroxidation, were reduced by EPS treatment. Conclusions: This study comprehensively showed that EPS produced from P. kribbensis PS04 enhances disease resistance in plants by the activation of defense-associated genes as well as through the enhancement of activities of defense-related enzymes. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:8.0pt; mso-para-margin-left:0cm; line-height:107%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri",sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

中文翻译：

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果聚糖形式克里本类芽孢杆菌 PS04 增强对立枯丝核菌和烟草花叶病毒的抗病性

背景：水稻纹枯病（由立枯丝核菌引起）和烟草花叶病毒是非常重要的植物病害，给全球作物生产造成巨大损失。Paenibacillus kribbensis PS04 是一种广谱生物防治剂，用于防治这些疾病。此前，来自 P. kribbensis PS04 的胞外多糖 (EPS) 已被纯化，并推断其结构为果聚糖。本研究旨在评估外源 EPS 处理对植物-病原体相互作用的影响。结果：外源EPS处理显着诱导植物防御基因，如苯丙氨酸解氨酶、过氧化氢酶、几丁质酶、丙二烯氧化合酶和PR1a蛋白。此外，随后用病原体（R. solani 或烟草花叶病毒）导致防御相关基因的更高表达。在EPS预处理的植物中也观察到防御相关酶、总酚和类黄酮的活性增加。EPS处理降低了植物中作为脂质过氧化指标的丙二醛含量。结论：本研究综合表明，从 P. kribbensis PS04 产生的 EPS 通过激活防御相关基因以及增强防御相关酶的活性来增强植物的抗病性。正常 0 false false false EN-US X-NONE X-NONE /* 样式定义 */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow：是；mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:8.0pt; mso-para-margin-left:0cm; 行高：107%；mso-分页：寡妇孤儿；字体大小：11.0pt; font-family:"Calibri",sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}