Tienda Sandra, Vida Carmen, Lagendijk Ellen, de Weert Sandra, Linares Irene, González-Fernández Jorge, Guirado Emilio, de Vicente Antonio, Cazorla Francisco M
Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.
Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", IHSM-UMA-CSIC, Málaga, Spain.
Front Microbiol. 2020 Aug 7;11:1874. doi: 10.3389/fmicb.2020.01874. eCollection 2020.
Biocontrol bacteria can be used for plant protection against some plant diseases. PCL1606 (PcPCL1606) is a model bacterium isolated from the avocado rhizosphere with strong antifungal antagonism mediated by the production of 2-hexyl, 5-propil resorcinol (HPR). Additionally, PcPCL1606 has biological control against different soil-borne fungal pathogens, including the causal agent of the white root rot of many woody crops and avocado in the Mediterranean area, . The objective of this study was to assess whether the semicommercial application of PcPCL1606 to soil can potentially affect avocado soil and rhizosphere microbial communities and their activities in natural conditions and under infection. To test the putative effects of PcPCL1606 on soil eukaryotic and prokaryotic communities, a formulated PcPCL1606 was prepared and applied to the soil of avocado plants growing in mesocosm experiments, and the communities were analyzed by using 16S/ITS metagenomics. PcPCL1606 survived until the end of the experiments. The effect of PcPCL1606 application on prokaryotic communities in soil and rhizosphere samples from natural soil was not detectable, and very minor changes were observed in eukaryotic communities. In the infested soils, the presence of strongly impacted the soil and rhizosphere microbial communities. However, after PcPCL1606 was applied to soil infested with , the prokaryotic community reacted by increasing the relative abundance of few families with protective features against fungal soilborne pathogens and organic matter decomposition (, ), but no new prokaryotic families were detected. The treatment of PcPCL1606 impacted the fungal profile, which strongly reduced the presence of in avocado soil and rhizosphere, minimizing its effect on the rest of the microbial communities. The bacterial treatment of formulated PcPCL1606 on avocado soils infested with resulted in biological control of the pathogen. This suppressiveness phenotype was analyzed, and PcPCL1606 has a key role in suppressiveness induction; in addition, this phenotype was strongly dependent on the production of HPR.
生防细菌可用于植物保护，防治某些植物病害。PCL1606（PcPCL1606）是从鳄梨根际分离出的一种模式细菌，通过产生2-己基-5-丙基间苯二酚（HPR）介导具有强大的抗真菌拮抗作用。此外，PcPCL1606对不同的土传真菌病原体具有生物防治作用，包括地中海地区许多木本作物和鳄梨白根腐病的病原体。本研究的目的是评估在自然条件下和感染情况下，将PcPCL1606半商业化应用于土壤是否可能影响鳄梨土壤和根际微生物群落及其活性。为了测试PcPCL1606对土壤真核生物和原核生物群落的假定影响，制备了配方化的PcPCL1606并将其应用于中宇宙实验中生长的鳄梨植物的土壤中，然后使用16S/ITS宏基因组学对群落进行分析。PcPCL1606存活到实验结束。未检测到PcPCL1606应用对天然土壤的土壤和根际样品中原核生物群落的影响，并且在真核生物群落中观察到非常微小的变化。在受侵染的土壤中，[病原体名称]的存在强烈影响土壤和根际微生物群落。然而，将PcPCL1606应用于受[病原体名称]侵染的土壤后，原核生物群落通过增加少数对真菌土传病原体和有机物分解具有保护特性的科的相对丰度做出反应（[科名称1]、[科名称2]），但未检测到新的原核生物科。PcPCL1606处理影响真菌谱，这大大减少了鳄梨土壤和根际中[病原体名称]的存在，将其对其余微生物群落的影响降至最低。配方化的PcPCL1606对受[病原体名称]侵染的鳄梨土壤进行细菌处理，实现了对病原体的生物防治。对这种抑制性表型进行了分析，PcPCL1606在抑制性诱导中起关键作用；此外，这种表型强烈依赖于HPR的产生。
