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:The fall armyworm (FAW) Spodoptera frugiperda is one of the most severe economic pests of multiple crops globally. Control of this pest is often achieved using insecticides; however, over time, S. frugiperda has developed resistance to new mode of action compounds, including diamides. Previous studies have indicated diamide resistance is a complex developmental process involving multiple detoxification genes. Still, the mechanism underlying the possible involvement of microRNAs in post-transcriptional regulation of resistance has not yet been elucidated. In this study, a global screen of microRNAs (miRNAs) revealed 109 known and 63 novel miRNAs. Nine miRNAs (four known and five novel) were differentially expressed between insecticide-resistant and -susceptible strains. Gene Ontology analysis predicted putative target transcripts of the differentially expressed miRNAs encoding significant genes belonging to detoxification pathways. Additionally, miRNAs are involved in response to diamide exposure, indicating they are probably associated with the detoxification pathway. Thus, this study provides comprehensive evidence for the link between repressed miRNA expression and induced target transcripts that possibly mediate diamide resistance through post-transcriptional regulation. These findings highlight important clues for further research to unravel the roles and mechanisms of miRNAs in conferring diamide resistance.
Project description:The histone 3 lysine 9 acetylation (H3K9ac) is an epigenetic marker widely distributed in plant genome, which could eThe histone 3 lysine 9 acetylation (H3K9ac) is an epigenetic marker widely distributed in plant genome, which could enhance gene transcription involved in stress-responsive gene expression. The physiological and molecular mechanisms underlying plant responses to insects are being increasingly studied, while epigenetic modifications such as histone acetylation and their potential regulation at the genomic level of transcription of hidden genes in plants damaged by insects remain largely unknown. In current study, we provided the genome-wide profiles of H3K9ac in rice (Oryza sativa) infested by fall armyworm (Spodoptera frugiperda, FAW) using chromatin immunoprecipitation sequencing (ChIP-Seq) and RNA sequencing (RNA-seq). RNA-seq data revealed that 3269 and 4609 genes were up-regulated at 3 h and 12 h after infestation with FAW, respectively. ChIP-Seq analysis revealed 1617 and 2617 genes modified by H3K9ac in rice infested with FAW at 3 h and 12 h, respectively, and H3K9ac was mainly enriched in the transcription start sites of genes.
Project description:Small nucleolar RNAs (snoRNA) function in guiding 2'-O-methylation and pseudouridylation of ribosomal RNAs. But we found that knock down of a C/D box snoRNA, Bm-15, can induce apoptosis of insect Spodoptera frugiperda Sf9 cells. For the genome sequence of Spodoptera frugiperda is incomplete, here with the de novo sequencing method, transcriptome of Spodoptera frugiperda cell line Sf9 were sequenced after being transfected with overexpression vector and repression probes of snoRNA Bm-15. Results showed that 21 apoptosis-related genes were up-regulated upon Bm-15 inhibition and down-regulated with Bm-15 overexpression.
Project description:Native host plant insect resistance in the maize inbred line Mp708 was developed by traditional plant breeding. Resistant Mp708 thwarts feeding by fall armyworm (Spodoptera frugiperda [J.E. Smith]; Lepidoptera: Noctuidae), numerous other lepidopteran pests, and the coleopteran western corn rootworm. This broad resistance makes it an excellent model for studying native host plant resistance mechanisms. In response to caterpillar feeding, Mp708 rapidly mobilizes Mir1-CP, a unique cysteine protease that appears to translocate from roots to the maize midwhorl where it accumulates. This accumulation correlates with a significant reduction in caterpillar growth resulting from diminished food utilization. In addition, the peritrophic membrane (PM) that surrounds the food bolus in the mudgut (MG) is severely damaged in caterpillars fed on sweet corn callus transformed to express the gene encoding Mir1-CP or on midwhorl tissue from resistant Mp708 maize. Functions of the PM include assisting digestion and protecting the epithelium of the caterpillar MG from physical and chemical damage. Consequently, the reduced growth of caterpillars that feed on Mp708 is probably due to the action of Mir1-CP on PM physiology. In fact, previous in vitro studies indicated that Mir1-CP was capable of permeabilizing the PM. The present study used both targeted (qRT-PCR) and global (mRNA-seq) transcriptome analyses to explore the effect of eating Mir1-CP expressing Mp708 maize on abundance of transcripts in the MG of fall armyworm larvae in comparison to MGs from larvae fed on susceptible Tx601 maize that does not express Mir1-CP. Expression of genes encoding proteins involved in PM production is upregulated in MGs from fall armyworm fed on Mp708. Also, several digestive enzymes (endopeptidases, aminopeptidases, lipases, amylase) were more highly expressed in MGs from larvae fed on Mp708 than MGs from larvae fed on Tx601. Impaired growth of larvae fed on Mp708 probably results from metabolic costs associated with higher production of PM constituents and digestive enzymes in a compensatory attempt to maintain MG function.
2012-12-01 | GSE42659 | GEO
Project description:Investogation of fall armyworm (Spodoptera frugiperda) gut microbiome and entomopathogenic fungus-induced pathobiome