Alteration of free amino acid concentrations in insect galls induced by Andricus mukaigawae (Hymenoptera; Cynipidae)

Abstract

1. Insect galls are abnormal plant growths that develop in response to a stimulus provided by a galling insect. The nutrition hypothesis suggests that the concentrations of nutritive compounds in galls are changed to provide optimum nutrition for the larvae and adults of galling insects. 2. To test the nutrition hypothesis, we determined the concentrations of 20 free amino acids in galls and in galled and ungalled twigs of Quercus fabri during the larval and adult stages of Andricus mukaigawae using high‐performance liquid chromatography with ultraviolet–visible detection. 3. At the larval stage, the concentrations of 12 out of 20 amino acids in A. mukaigawae galls were significantly higher than those in galled and ungalled twigs. Asparagine and tryptophan were the most abundant nonessential and essential amino acids, respectively, in A. mukaigawae galls. 4. At the adult stage, the concentrations of most amino acids, except proline, were significantly lower in A. mukaigawae galls than in galled and ungalled twigs. The A. mukaigawae adults may not manipulate amino acid levels because the adults do not feed on galls. The decrease of amino acid levels in adult galls may be viewed as a depletion. 5. The composition of free amino acids in A. mukaigawae galls was significantly different from the composition in galled and ungalled twigs in both the larval and adult stages. 6. Our results may support the nutrition hypothesis. We suggest that a high concentration of proline in A. mukaigawae galls may protect larvae and adults from plant defense responses.

Comparison of Auxin and Cytokinins Concentrations, and the Structure of Bacterial Community between Host Twigs and Lithosaphonecrus arcoverticus Galls

“…The high contents of IAA, tZR and iP may alter the levels and composition of nutrients in L. arcoverticus galls, thus providing unique carbon and nitrogen sources for the bacterial community in L. arcoverticus galls. In fact, the levels and composition of carbohydrates [47], lipids [48,49], protein [50,51] and free amino acids [52] in cynipid galls differ from those in adjacent galled tissues. Finally, the auxins and cytokinins are involved in the plant's defense against pathogens through communicating with jasmonic acid and salicylic acid signaling pathways [53][54][55].…”

Offspring performance and female preference of Pagiophloeus tsushimanus (coleoptera: curculionidae) on three Lauraceae tree species: A potential risk of host shift caused by larval experience

“…High‐dimensional data are very common in biology and occur when multiple features are measured for each sample (Lina et al., 2020; Raghava et al., 2010; Yang et al., 2020). Principal component analysis (PCA) is widely used to simplify the complexity in high‐dimensional data while retaining trends and patterns (Sando & Hino, 2020).…”

The Diversity and Dynamics of Fungi in Dryocosmus kuriphilus Community

“…The fungal community structures of aphid galls [ 48 ] and midge galls [ 49 ] also differed from those associated with the corresponding host plants. For the insect galls of D. kuriphilus and other gall wasps, the chemical composition, as well as the concentrations of amino acids, carbohydrates, lipids, lignin and secondary metabolites were markedly different from those of the host plants [ 42 , 50 , 51 , 52 , 53 , 54 ]. We propose that the chemical components and concentrations of insect galls induced by D. kuriphilus may affect the fungal community structure and provide a particular habitat for the fungi associated with the insect galls.…”