Ullah Aziz, Shah Ateeq, Chen Shih-Hsuan Ethan, Shah Aftab, Rodriguez-Ramos Jean C, Zaman Rashaduz, Erbilgin Nadir
Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada.
Plant Cell Environ. 2025 Jul;48(7):5236-5249. doi: 10.1111/pce.15503. Epub 2025 Apr 1.
Fungal endophytes can alter plant resistance against herbivores by indirectly influencing plant secondary metabolism or through direct effects of their own metabolism. However, the role of fungal endophytes in conifer defences to insect herbivores remains largely unknown. We characterised the endophytic fungal communities and terpene concentrations of 30 white spruce families across two sites. We determined the effects of fungal endophytes on a defoliating insect, eastern spruce budworm, by testing the budworm responses to media amended with fungal endophytes or exposing them to their volatile organic compounds. We further examined whether the changes in the endophytic fungal communities and abundance alter the terpene concentrations of white spruce by inoculating seedlings with endophytic fungi. Terpene and fungal community compositions in mature trees varied among families and sites. The bioassays showed fungal endophytes can kill budworms or reduce their fitness due to the toxicity of fungal mycelium or volatile compounds. The inoculation experiments demonstrated that the changes in fungal communities and abundance can alter the terpene concentrations in seedlings. We developed a "Plant Partnership Hypothesis" to reflect the role of fungal endophytes in plant resistance to insect herbivores, demonstrating a co-evolutionary relationship among fungal endophytes, tree defences, and insect herbivores.
内生真菌可通过间接影响植物次生代谢或通过自身代谢的直接作用来改变植物对食草动物的抗性。然而，内生真菌在针叶树对昆虫食草动物防御中的作用仍 largely unknown。我们对两个地点的30个白云杉家族的内生真菌群落和萜烯浓度进行了表征。我们通过测试芽虫对用内生真菌改良的培养基的反应或将它们暴露于其挥发性有机化合物来确定内生真菌对落叶昆虫东部云杉芽虫的影响。我们进一步通过用内生真菌接种幼苗来研究内生真菌群落和丰度的变化是否会改变白云杉的萜烯浓度。成熟树木中的萜烯和真菌群落组成在家族和地点之间有所不同。生物测定表明，内生真菌可由于真菌菌丝体或挥发性化合物的毒性而杀死芽虫或降低其适合度。接种实验表明，真菌群落和丰度的变化可改变幼苗中的萜烯浓度。我们提出了一个“植物伙伴关系假说”来反映内生真菌在植物对昆虫食草动物抗性中的作用，证明了内生真菌、树木防御和昆虫食草动物之间存在共同进化关系。
