Project description:We wished to investigate if adaptation to host-plant diet is the basis of differentiation for two strains of Spodoptera frugiperda (Lepidoptera:Noctuidae). We performed reciprocal transplant experiments in laboratory conditions, feeding each strain (sf-C and sf-R) with artificial diet, corn plants or rice plants. RNA-Seq was performed on pooled 4th instar larvae from this experiment. We compared this transcriptional response with that of individual 4th instar larvae collected in corn and grass fields in Florida.
Project description:Insect gut microbiota plays important roles in acquiring nutrition, preventing pathogens infection, immune responses, and communicating with the environment. Gut microbiota can be affected by some external factors such as foods, temperature, and antibiotics. Spodoptera frugiperda (Lepidoptera: Noctuidae) is an important destructive pest of grain crops all over the world. The function of gut microbiota in S. frugiperda remains to be investigated. In this study, we fed the S. frugiperda with the antibiotic mixture (penicillin, gentamicin, rifampicin, and streptomycin) to perturb the gut microbiota, and further examined the effect of dysbiosis in gut microbiota on the gene expression of S. frugiperda by RNA sequencing. We found the composition and diversity of the gut bacterial community were changed in S. frugiperda after antibiotics treatmen, and the expression of genes related to energy and metabolic process were affected after antibiotics exposure in S. frugiperda. Our work will help understand the role of gut microbiota in insects.
2021-08-06 | GSE175476 | GEO
Project description:Microbial community diversity of Spodoptera frugiperda (Lepidoptera: Noctuidae)
Project description:During the over 300 million years of co-evolution between herbivorous insects and their host plants, a dynamic equilibrium of evolutionary arms race has been established. However, the co-adaptation between insects and their host plants is a complex process, often driven by multiple evolutionary mechanisms. We found that various lepidopteran pests that use maize as a host exhibit differential adaptation to the plant secondary metabolites, benzoxazinoids (BXs). Notably, the Spodoptera genus, including Spodoptera frugiperda (fall armyworm) and Spodoptera litura (cotton leafworm), demonstrate greater tolerance to BXs compared to other insects. Through comparative transcriptomic analysis of the midgut, we identified four candidate genes potentially involved in BXs detoxification in S. frugiperda. Subsequently, we confirmed two UGT genes, Sfru33T10 and Sfru33F32, as key players in BXs detoxification using CRISPR/Cas9 gene-editing technology. Phylogenetic analysis revealed that Sfru33T10 evolved independently within the Noctuidae family and is involved in the glycosylation of HDMBOA, while Sfru33F32 evolved independently within the Spodoptera genus and functions as a key detoxification enzyme responsible for the glycosylation of both DIMBOA and HMBOA. Our study demonstrates that the UGT gene family plays a crucial role in the adaptation of noctuid insects to maize, with multiple independent evolutionary events within the Noctuidae family and the Spodoptera genus contributing significantly to host adaptation.
Project description:Nematodes such as Steinernema carpocapsae are used as organic pesticides because of their ability to prey on live insects. They do so thanks to their symbiotic bacteria, that they release within the hemocoel of insects. In this study we wanted to study how Spodoptera frugiperda, a Lepidoptera pest of crops becoming invasive around the world, defend themselves against the nematodes. We infested S. frugiperda larvae with nematodes and dissected three tissues: the midgut, the fat body and the hemocytes at two time-points: 8 h and 15 h after infestation. We performed single-end RNA-seq on these samples to study the tissue specificity of S. fru response, as well as its dynamic.
