The gut microbiota composition of Trichoplusia ni is adaptable and may influence its polyphagous behavior

Authors: LEITE-MONDIN, M - Colorado State University; DILEGGE, M - Colorado State University; Manter, Daniel; WEIR, T - Colorado State University; SILVA-FILHO, M - Colorado State University; VIVANCO, J - Colorado State University

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/15/2021
Publication Date: 3/11/2021
Citation: Leite-Mondin, M., Dilegge, M.J., Manter, D.K., Weir, T.L., Silva-Filho, M.C., Vivanco, J.M. 2021. The gut microbiota composition of Trichoplusia ni is adaptable and may influence its polyphagous behavior. Scientific Reports. 11(1). Article e5786. https://doi.org/10.1038/s41598-021-85057-0.
DOI: https://doi.org/10.1038/s41598-021-85057-0

Interpretive Summary: Insects are the most abundant animals on the planet and the microbiota inside their intestine result in both beneficial and pathogenic interactions. Insects are known plant pests, and some of them such as Trichoplusia ni, feed widely on a variety of crops of economic importance. In this study, T. ni was fed for four generations on distinct diets: (1) Arabidopsis thaliana Col-0 leaves; (2) Solanum lycopersicum cv. Rutgers leaves (tomatoes); and (3) an Artificial Diet. After four generations, the insects were given a choice to feed on one of the three diets; all populations preferred the diet that they were fed for the previous four generations. In the same generation, the microbial composition of the insect gut was evaluated to determine if the diet influenced the structure of the microbial communities. The phyla Proteobacteria, Firmicutes and Actinobacteria were the most abundant regardless of the diet. The population fed with A. thaliana had higher proportions of Shinella, Terribacillus, and Propionibacterium, and these phyla have been shown to degrade glucosinolates, which are produced by A. thaliana and break down into insect-deterring compounds produced by A. thaliana. Interestingly, these genera were also present in the leaves of A. thaliana in considerable amounts. The population fed with leaves (S. lycopersicum) expressed increased relative abundances of the Agrobacterium and Rhizobium genera. These microbial members can degrade alkaloids; which are produced by tomatoes. These two genera were also associated with leaves of the vegetable. It appears that microbial members providing these detoxification abilities are taken up from the plant diet itself and may also contribute to the success of insect feeding and survival.

Technical Abstract: Insects are the most abundant animals on the planet and the microbiota inside their intestine result in both beneficial and pathogenic interactions. Insects are known plant pests, and some of them such as Trichoplusia ni, feed widely on a variety of crops of economic importance. In this study, T. ni was fed for four generations on distinct diets: (1) Arabidopsis thaliana Col-0 leaves; (2) Solanum lycopersicum cv. Rutgers leaves (tomatoes); and (3) an Artificial Diet. After four generations, the insects were given a choice to feed on one of the three diets; all populations preferred the diet that they were fed for the previous four generations. In the same generation, the microbial composition of the insect gut was evaluated to determine if the diet influenced the structure of the microbial communities. The phyla Proteobacteria, Firmicutes and Actinobacteria were the most abundant regardless of the diet. The population fed with A. thaliana had higher proportions of Shinella, Terribacillus, and Propionibacterium, and these phyla have been shown to degrade glucosinolates, which are produced by A. thaliana and break down into insect-deterring compounds produced by A. thaliana. Interestingly, these genera were also present in the leaves of A. thaliana in considerable amounts. The population fed with leaves (S. lycopersicum) expressed increased relative abundances of the Agrobacterium and Rhizobium genera. These microbial members can degrade alkaloids; which are produced by tomatoes. These two genera were also associated with leaves of the vegetable. It appears that microbial members providing these detoxification abilities are taken up from the plant diet itself and may also contribute to the success of insect feeding and survival.