Wallis Christopher M, Galarneau Erin R-A
Crop Diseases Pest and Genetics Research Unit, USDA-ARS San Joaquin Valley Agricultural Sciences Center, Parlier, CA, United States.
Viticulture and Enology Department, University of California, Davis, Davis, CA, United States.
Front Plant Sci. 2020 Dec 15;11:580753. doi: 10.3389/fpls.2020.580753. eCollection 2020.
Plants rely on a variety of ways to protect themselves from being fed upon, including production of specific compounds such as those termed as phenolics. Phenolics are often described as important in plant health and numerous studies have concluded they increase as a result of insect feeding, pathogen infection, or beneficial microorganism colonization. However, there are some studies reaching differing conclusions. Therefore, meta-analyses were conducted to observe whether common trends in phenolic induction in plants can be made when they become hosts to insects or microorganisms. Four hypotheses were tested. The first was that total phenolics increase as a generic response, and meta-analyses confirmed that this occurs when plants are infested with insects or colonized by bacterial or fungal microorganisms, but not for oomycetes. The second hypothesis was that phenolic induction is different when a beneficial microorganism colonizes a plant vs. when a plant is infected by a pathogen. Beneficial bacteria, pathogenic bacteria, and beneficial fungi produced increased phenolic levels in plant hosts, but fungal pathogens did not. The third hypothesis was that insect feeding method on plant hosts determines if phenolics are induced. Chewing induced phenolics but piercing-sucking and wood-boring did not. Lastly, we used meta-analyses to determine if annual or perennials rely on phenolic induction in different amounts, and even though annuals had significantly increased phenolic levels but perennials did not, it was observed that phenolic induction was not statistically different when plant type was considered. These results demonstrate that phenolic induction is a common response in plant hosts exposed to feeding or colonization, with specific exceptions such a pathogenic fungi and piercing-sucking insects.
植物依靠多种方式来保护自己不被取食，包括产生特定的化合物，如酚类物质。酚类物质通常被认为对植物健康很重要，许多研究得出结论，它们会因昆虫取食、病原体感染或有益微生物定殖而增加。然而，也有一些研究得出了不同的结论。因此，进行了荟萃分析，以观察当植物成为昆虫或微生物的宿主时，酚类物质诱导的常见趋势是否存在。测试了四个假设。第一个假设是总酚类物质作为一种普遍反应会增加，荟萃分析证实，当植物受到昆虫侵害或被细菌或真菌微生物定殖时会出现这种情况，但卵菌不会。第二个假设是，当有益微生物定殖植物与植物被病原体感染时，酚类物质的诱导情况不同。有益细菌、致病细菌和有益真菌会使植物宿主中的酚类水平升高，但真菌病原体不会。第三个假设是昆虫在植物宿主上的取食方式决定了酚类物质是否会被诱导。咀嚼会诱导酚类物质产生，但刺吸式和蛀干式取食不会。最后，我们使用荟萃分析来确定一年生植物或多年生植物是否依赖不同量的酚类物质诱导，尽管一年生植物的酚类水平显著升高而多年生植物没有，但观察到考虑植物类型时酚类物质诱导在统计学上没有差异。这些结果表明，酚类物质诱导是植物宿主在受到取食或定殖时的一种常见反应，但存在特定的例外情况，如致病真菌和刺吸式昆虫。
