Antagonistic Regulation, Yet Synergistic Defense: Effect of Bergapten and Protease Inhibitor on Development of Cowpea Bruchid Callosobruchus maculatus

Abstract

The furanocoumarin compound bergapten is a plant secondary metabolite that has anti-insect function. When incorporated into artificial diet, it retarded cowpea bruchid development, decreased fecundity, and caused mortality at a sufficient dose. cDNA microarray analysis indicated that cowpea bruchid altered expression of 543 midgut genes in response to dietary bergapten. Among these bergapten-regulated genes, 225 have known functions; for instance, those encoding proteins related to nutrient transport and metabolism, development, detoxification, defense and various cellular functions. Such differential gene regulation presumably facilitates the bruchids' countering the negative effect of dietary bergapten. Many genes did not have homology (E-value cutoff 10−6) with known genes in a BlastX search (206), or had homology only with genes of unknown function (112). Interestingly, when compared with the transcriptomic profile of cowpea bruchids treated with dietary soybean cysteine protease inhibitor N (scN), 195 out of 200 coregulated midgut genes are oppositely regulated by the two compounds. Simultaneous administration of bergapten and scN attenuated magnitude of change in selected oppositely-regulated genes, as well as led to synergistic delay in insect development. Therefore, targeting insect vulnerable sites that may compromise each other's counter-defensive response has the potential to increase the efficacy of the anti-insect molecules.

Genomic evidence that resource-based trade-offs limit host-range expansion in a seed beetle

“…However, without additional work to identify the specific genes involved (e.g., Guo et al. ; Johnston et al. ; Roop et al.…”

Biochemicals Associated With Callosobruchus Chinensis Resistance in Soybean.

“…Soybean has been reported to contain and produce biochemicals that make it fairly resistant to insect pests. Soybeans produce a wide range of secondary metabolites, or allelochemicals, to protect themselves from devastation by animals, insects and pathogens (Guo et al, 2012). Plant toxic secondary metabolites are important defensive traits involved in plant defense against insect pests (War et al, 2013).…”

“…They act either directly on insect pests through antibiosis or indirectly through antixenosis by developing the non-preference for insects feeding on the seeds (War et al, 2013). The toxic secondary metabolites when ingested by insects, they decrease larval weight, extends generation time and induce mortality (Guo et al, 2012).…”

“…They act either directly on insect pests through antibiosis or indirectly through antixenosis by developing the non-preference for insects feeding on the seeds (War et al, 2013). The toxic secondary metabolites when ingested by insects, they decrease larval weight, extends generation time and induce mortality (Guo et al, 2012).Bearing in mind the importance of soybean in nutrition and economic aspects, it was deemed necessary to carry out an investigation on soybean genotypes with the aim of identifying biochemicals that are associated with C. chinensis resistance in soybean genotypes. In this study it was hypothesized that (i) soybean contains more than one type of metabolite which are responsible for and associated with bruchid resistance; (ii) soybean genotypes contain varying amounts of resistance metabolites.…”

Evolutionary genetics of host shifts in herbivorous insects: insights from the age of genomics

“…Finally, although we are starting to pinpoint genomic regions associated with host use in different insects, causative links between genotype, phenotype, and fitness are lacking . Ultimately, understanding the causal mechanisms underlying genetic correlations among host‐related traits will require us to identify specific genes, mutations, and molecular mechanisms …”