虎杖象甲培植真菌营养特性及对菌丝附属物形成的影响

虎杖象甲培植共生真菌形成的共生体系是植菌昆虫菌业中的典型代表。共生真菌Penicillium herquei如何向虎杖象甲Euops chinensis提供营养尚未明确。本研究发现共生真菌P. herquei的菌丝表面存在大量瘤状凸起物及由凸起物衍生的附属丝等特化结构,该结构可能为虎杖象甲提供营养;对共生真菌的营养研究表明,共生真菌能高效利用山梨醇、蔗糖、海藻糖、葡萄糖等单糖或双糖,以及酪氨酸、甘氨酸、谷氨酰胺等昆虫非必须氨基酸,同时在高碳和最适碳源条件下有利于菌丝特化附属物的产生。研究结果不仅提供了植菌卷叶象甲菌业中共生真菌在营养方面的适应性进化证据,而且为进一步揭示共生真菌适应卷叶象甲的营养机制奠定了基础。

Nutritional requirements and their effects on the formation of hyphal surface appendages of symbiotic fungus cultivated by attelabid weevil

Association between Euops chinensis and its symbiotic fungus Penicillium herquei is a typical attelabid fungiculture. How P. herquei provides nutrition for E. chinensis is unknown. We found that there were abundant appendages of nodular protrusions and networks on the hyphal surface of P. herquei, which might be the nutrient for host weevil. The nutritional requirements of P. herquei indicated mono- and di-saccharides such as glucitol, sucrose, trehalose, and glucose as carbon sources and non-essential amino acids of insect such as tyrosine, glycine, and glutamine as nitrogen sources supported the well growth of P. herquei. High-carbon and optimal carbon source environments can promote production of more appendages on the hyphal surface. The results not only provide evidence of symbiotic fungus nutritional adaptation in the attelabid weevil fungiculture, but also lay the foundation for further revealing the nutritional mechanism of the symbiotic fungus adapting to the leaf rolling weevil.