Department of Agroecology, Aarhus University, Flakkebjerg, Denmark.
PLoS One. 2020 Sep 14;15(9):e0238943. doi: 10.1371/journal.pone.0238943. eCollection 2020.
Inoculating plants with entomopathogenic fungi may influence plant nutrient uptake and growth, and herbivore performance. Knowledge is limited concerning the effects of this symbiosis on higher trophic levels. We examined how fungal treatment of faba bean seeds with the entomopathogenic fungus Beauveria bassiana influenced the choice-behavior and development of the aphid parasitoid Aphidius colemani. We also sampled plant material for analysis of changes in expression of genes related to plant defense pathways. While parasitoids were compatible with plants inoculated with B. bassiana initially (66 vs. 65% parasitization on inoculated and control plants, respectively; similar development times of parasitoids: 9.2 days), the emergence of adult parasitoids originating from aphids on fungus treated plants was significantly lower (67 vs. 76%, respectively). We also found that the defense response changed, similar to induced systemic resistance, when plants were treated with B. bassiana, similarly to what has been found for other plant symbiotic microorganisms. These novel findings show that although the application of entomopathogenic fungi to plants can alter the plants' defense against herbivores, it may also have an impact on beneficial insects, so their function and use should be evaluated on a case-by-case basis.
给植物接种昆虫病原真菌可能会影响植物的养分吸收和生长，以及草食性动物的表现。关于这种共生关系对更高营养级的影响，我们的了解有限。我们研究了用昆虫病原真菌球孢白僵菌处理蚕豆种子对蚜虫寄生蜂菜蚜茧蜂选择行为和发育的影响。我们还采集了植物材料，以分析与植物防御途径相关的基因表达变化。虽然寄生蜂最初与接种 B. bassiana 的植物兼容（分别在接种和对照植物上寄生率为 66%和 65%；寄生蜂的发育时间相似：9.2 天），但源自真菌处理植物上蚜虫的成虫寄生蜂的出现率明显较低（分别为 67%和 76%）。我们还发现，当植物被 B. bassiana 处理时，防御反应发生变化，类似于诱导系统抗性，这与其他植物共生微生物的发现相似。这些新发现表明，尽管向植物施用昆虫病原真菌可以改变植物对草食动物的防御，但它也可能对有益昆虫产生影响，因此应根据具体情况评估它们的功能和用途。
