Gut bacterium promotes host fitness in special ecological niche by affecting sugar metabolism in Drosophila suzukii

Abstract

As an important fruit pest of global significance, Drosophila suzukii occupies a special ecological niche, with the characteristics of high sugar and low protein contents. This niche differs from those occupied by other fruit‐damaging Drosophila species. Gut bacteria substantially impact the physiology and ecology of insects. However, the contribution of gut microbes to the fitness of D. suzukii in their special ecological niche remains unclear. In this study, the effect of Klebsiella oxytoca on the development of D. suzukii was examined at physiological and molecular levels. The results showed that, after the removal of gut microbiota, the survival rate and longevity of axenic D. suzukii decreased significantly. Reintroduction of K. oxytoca to the midgut of D. suzukii advanced the development level of D. suzukii. The differentially expressed genes and metabolites between axenic and K. oxytoca‐reintroduced D. suzukii were enriched in the pathways of carbohydrate metabolism. This advancement was achieved through an increased glycolysis rate and the regulation of the transcript level of key genes in the glycolysis/gluconeogenesis pathway. Klebsiella oxytoca is likely to play an important role in increasing host fitness in their high‐sugar ecological niche by stimulating the glycolysis/gluconeogenesis pathway. As a protein source, bacteria can also provide direct nutrition for D. suzukii, which depends on the quantity or biomass of K. oxytoca. This result may provide a new target for controlling D. suzukii by inhibiting sugar metabolism through eliminating the effect of K. oxytoca and thus disrupting the balance of gut microbial communities.

A chromosome-level genome assembly ofDrosophila madeirensis, a fruit fly species endemic to the island of Madeira

“…Out of 146 contigs, 24 were assigned to Gluconobacter (5.5 Mb in total), 9 were assigned to Serratia (5.1 Mb), 1 was assigned to Klebsiella (85 kb), and 1 was assigned to Komagataeibacter (45 kb) bacterial species. All these bacteria are inhabitants of the Drosophila gut (Staubach et al 2013;Chaston et al 2016;Ramírez-Camejo et al 2017;Gao et al 2023). We analyzed the sequence after removing these contigs derived from bacteria.…”

Enterococcus casseliflavus regulates amino acid metabolism in edible insect Clanis bilineata tsingtauica: a functional metagenomics study

“…In Riptortus pedestris , the presence of Burkholderia in the gut results in higher levels of juvenile hormone (JH), leading to increased fecundity and storage proteins ( Lee et al, 2019 ). Moreover, it has been demonstrated that Klebsiella oxytoca can boost the developmental stage of Drosophila suzukii by activating the glycolysis pathway ( Gao et al, 2023 ). The gut microbiota in Drosophila melanogaster modulates the insulin signaling pathway, a key regulator of insect growth and nutrient homeostasis, to regulate nutrient allocation in the host ( Shin et al, 2011 ).…”