Project description:Predatory bugs capture prey by injecting venom from their salivary glands using specialized stylets. Understanding venom function has been impeded by a scarcity of knowledge of their venom composition. We therefore examined the proteinaceous components of the salivary venom of the predatory stink bug Arma chinensis (Hemiptera: Pentatomidae). Using gland extracts and venoms from 5th-instar nymphs or adult females, we performed shotgun proteomics combined with venom gland transcriptomics. We found that the venom of A. chinensis comprised a complex suite of over a hundred individual proteins, including oxidoreductases, transferases, hydrolases, ligases, protease inhibitors, and recognition, transport and binding proteins. Besides the uncharacterized proteins, hydrolases such as venom serine proteases, cathepsins, phospholipase A2, phosphatases, nucleases, alpha-amylases, and chitinases constitute the most abundant protein families. However, salivary proteins shared by and unique to other predatory heteropterans were not detected in A. chinensis venom. Injection of the proteinaceous (> 3 kDa) venom fraction of A. chinensis gland extracts or venom into its prey, the larvae of the Oriental armyworm Mythimna separata (Walker, 1865), revealed insecticidal activity against lepidopterans. Our data expands the knowledge of heteropteran salivary proteins and suggests predatory asopine bugs as a novel source for bioinsecticides.
2023-07-20 | PXD040272 | Pride
Project description:Chromosomal level genome of the Oriental armyworm Mythinma separata
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.
Project description:Fourth-instar larvae of beet armyworm were injected with conidial suspension of pks14-overexpressing strain. Inoculated larvae were collected on 3, 5, and 7 DPI. Crude extracts from the whole inoculated larvae were collected and extracted with methanol.
Project description:Fourth-instar larvae of beet armyworm were injected with conidial suspension of pks15-overexpressing strain. Inoculated larvae were collected on 3, 5, and 7 DPI. Crude extracts from the whole inoculated larvae were collected and extracted with methanol.
Project description:Fourth-instar larvae of beet armyworm were injected with saline and used as a control.
Inoculated larvae were collected on 3, 5, and 7 DPI. Crude extracts from the whole inoculated larvae were collected and extracted with methanol.
Project description:Fourth-instar larvae of beet armyworm were injected with saline and used as a control. Inoculated larvae were collected on 3, 5, and 7 DPI. Crude extracts from the whole inoculated larvae were collected and extracted with methanol.
Project description:Fourth-instar larvae of beet armyworm were injected with conidial suspension of pks15-knockout strain. Inoculated larvae were collected on 3, 5, and 7 DPI. Crude extracts from the whole inoculated larvae were collected and extracted with methanol.
Project description:Fourth-instar larvae of beet armyworm were injected with conidial suspension of pks14-knockout strain. Inoculated larvae were collected on 3, 5, and 7 DPI. Crude extracts from the whole inoculated larvae were collected and extracted with methanol.