Host plant defense produces species specific alterations to flight muscle protein structure and flight-related fitness traits of two armyworms

Abstract

Insects manifest phenotypic plasticity in their development and behavior in response to plant defenses, via molecular mechanisms that produce tissue-specific changes. Phenotypic changes might vary between species that differ in their preferred hosts and these effects could extend beyond larval stages. To test this, we manipulated the diet of southern armyworm (SAW; Spodoptera eridania) and fall armyworm (FAW; Spodoptera frugiperda) using a tomato mutant for jasmonic acid plant defense pathway (def1), and wild-type plants, and then quantified gene expression of Troponin t (Tnt) and flight muscle metabolism of the adult insects. Differences in Tnt spliceform ratios in insect flight muscles correlate with changes to flight muscle metabolism and flight muscle output. We found that SAW adults reared on induced def1 plants had a higher relative abundance (RA) of the A isoform of Troponin t (Tnt A) in their flight muscles; in contrast, FAW adults reared on induced def1 plants had a lower RA of Tnt A in their flight muscles compared with adults reared on def1 and controls. Although mass-adjusted flight metabolic rate showed no independent host plant effects in either species, higher flight metabolic rates in SAW correlated with increased RA of Tnt A. Flight muscle metabolism also showed an interaction of host plants with Tnt A in both species, suggesting that host plants might be influencing flight muscle metabolic output by altering Tnt. This study illustrates how insects respond to variation in host plant chemical defense by phenotypic modifications to their flight muscle proteins, with possible implications for dispersal.

Identification of genes and gene expression associated with dispersal capacity in the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae)

“…Differential expression of flight muscle-related genes affects flight capabilities in two armyworm species ( Spodoptera eridania and Spodoptera frugiperda ; Portman et al, 2020 ). We identified several differentially expressed genes that indicate the importance of muscle function and maintenance in flight in mountain pine beetle.…”

“…In another dispersing pest species, the cotton bollworm, Helicoverpa armigera , such continuous traits associate with large suites of genes ( Jones et al, 2015 ). Disentangling the mechanisms that underlie flight capacity can provide valuable insights into the dispersal and spread of economically important insect species ( Kristensen, De Barro & Schellhorn, 2013 ; Portman et al, 2020 ).…”

Peer Review #1 of "Identification of genes and gene expression associated with dispersal capacity in the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae) (v0.1)"

“…capabilities in two armyworm species (Spodoptera eridania and Spodoptera frugiperda; Portman et al 2020). We identified several differentially expressed genes that indicate the importance of muscle function and maintenance in flight in mountain pine beetle.…”

“…In another dispersing pest species, the cotton bollworm, Helicoverpa armigera, such continuous traits associate with large suites of genes (Jones et al 2015). Disentangling the mechanisms that underlie flight capacity can provide valuable insights into the dispersal and spread of economically important insect species (Kristensen et al 2013;Portman et al 2020).…”

Tobacco Hornworm (Manduca sexta) Oral Secretion Elicits Reactive Oxygen Species in Isolated Tomato Protoplasts

“…M. sexta (tobacco hornworm) is a crucial insect model used to test both ecological effects and molecular mechanisms underlying plant-herbivore interaction research [7,9,[34][35][36]. M. sexta is a specialist on Solanaceae, which includes Solanum lycopersicum (tomato), which also serves as an excellent cellular model for plant defense-related studies [37]. By utilizing a ROS-sensing dye 2 ,7 -dichlorodihydrofluorescein diacetate (CM-H 2 DCFDA)-based cell imaging technique, we efficiently measured transient elevation in ROS generation upon application of M. sexta OS.…”