Responses of Soil Microbial Communities in the Rhizosphere of Cucumber (Cucumis sativus L.) to Exogenously Applied p-Hydroxybenzoic Acid
Responses of Soil Microbial Communities in the Rhizosphere of Cucumber (Cucumis sativus L.) to Exogenously Applied p-Hydroxybenzoic Acid
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DOI：
10.1007/s10886-012-0156-0
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发表时间：
2012-06
影响因子：
2.3
通讯作者：
Xingang Zhou;Gaobo Yu;Fengzhi Wu
中科院分区：
文献类型：
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作者：
Xingang Zhou;Gaobo Yu;Fengzhi Wu
土壤生物特性的变化被认为是土壤病的原因之一，这种现象发生在连续的单一作物制度中。然而，这些变化的原因尚不清楚。本研究旨在阐明黄瓜（Cucumis sativusL.）在黄瓜盆栽试验中，对羟基苯甲酸每隔一天施用一次，连续施用10天。然后，在根际土壤中的细菌和真菌群落的结构和大小，脱氢酶活性和微生物碳生物量（MCB）进行了评估。采用聚合酶链反应（PCR）-变性梯度凝胶电泳（DGGE）和实时荧光定量PCR（real-time PCR）技术分析了黄瓜根际细菌和真菌群落结构和大小，结果表明，对羟基苯甲酸抑制黄瓜幼苗生长，促进根际脱氢酶活性、MBC含量和细菌和真菌群落大小。外施PHBA后，微生物菌群和真菌菌群的反应不同。PHBA降低了根际细菌群落的Shannon-Wiener指数，但增加了根际真菌群落的Shannon-Wiener指数。此外，根际真菌群落结构对PHBA酸的响应具有浓度依赖性，而根际细菌群落结构对PHBA酸的响应则不明显。研究结果表明，PHBA在黄瓜与土壤微生物之间的化学相互作用中起着重要作用，可以解释连续单作黄瓜系统中土壤微生物群落的变化。
Changes in soil biological properties have been implicated as one of the causes of soil sickness, a phenomenon that occurs in continuous monocropping systems. However, the causes for these changes are not yet clear. The aim of this work was to elucidate the role ofp-hydroxybenzoic acid (PHBA), an autotoxin of cucumber (Cucumis sativusL.), in changing soil microbial communities.p-Hydroxybenzoic acid was applied to soil every other day for 10 days in cucumber pot assays. Then, the structures and sizes of bacterial and fungal communities, dehydrogenase activity, and microbial carbon biomass (MCB) were assessed in the rhizosphere soil. Structures and sizes of rhizosphere bacterial and fungal communities were analyzed by polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) and real-time PCR, respectively.p-Hydroxybenzoic acid inhibited cucumber seedling growth and stimulated rhizosphere dehydrogenase activity, MBC content, and bacterial and fungal community sizes. Rhizosphere bacterial and fungal communities responded differently to exogenously applied PHBA. The PHBA decreased the Shannon-Wiener index for the rhizosphere bacterial community but increased that for the rhizosphere fungal community. In addition, the response of the rhizosphere fungal community structure to PHBA acid was concentration dependent, but was not for the rhizosphere bacterial community structure. Our results indicate that PHBA plays a significant role in the chemical interactions between cucumber and soil microorganisms and could account for the changes in soil microbial communities in the continuously monocropped cucumber system.