Glucosinolate Profiles in Cabbage Genotypes Influence the Preferential Feeding of Diamondback Moth (Plutella xylostella)

Abstract

Diamondback moth (DBM), Plutella xylostella L., is a devastating pest of cabbage worldwide whose feeding attributes are influenced by glucosinolate profiles of the plant. Identifying the specific glucosinolates associated with plants’ resistance mechanism can provide cues to novel points of intervention in developing resistant cultivars. We studied the DBM larval feeding preference and extent of damage on cabbage leaves via controlled glass-house and in vitro multiple- and two-choice feeding tests. These feeding attributes were associated with the individual glucosinolate profiles, analyzed by HPLC, of each of the eight cabbage genotypes using multivariate analytical approach to identify the glucosinolates that may have roles in resistance. Both the glass-house and in vitro multiple-choice feeding tests identified the genotype BN4303, BN4059, and BN4072 as the least preferred (resistant) and Rubra, YR Gold and BN3383 as most preferred (susceptible) genotypes by DBM larvae. The principal component analysis separated the genotypes based on lower feeding scores in association with higher contents of glucobrassicin, glucoiberin, glucoiberverin in one direction and 4-hydroxyglucobrassicin, glucoerucin, glucoraphanin, and progoitrin in opposite direction in a way to explain the major variation in resistant versus susceptible genotypes based on their extent of preference and leaf area damage. The simultaneous presence (or higher contents) of glucobrassicin, glucoiberin, and glucoiberverin and the absence (or lower contents) of 4-hydroxyglucobrassicin, glucoerucin, glucoraphanin, and progoitrin in the least preferred genotypes and vice-versa in most preferred genotypes indicated their apparent role as putative repellents and attractants of DBM larvae in cabbage genotypes, respectively. These novel findings add to the current knowledgebase on the roles of glucosinolates in plant–herbivore interactions and will be helpful in setting breeding priorities for improving the resistance against DBM in cabbage using conventional and biotechnological approaches.

Peer Review #2 of "Feeding intensity of insect herbivores is associated more closely with key metabolite profiles than phylogenetic relatedness of their potential hosts (v0.2)"

“…We found no associations with total GS, but only with GS profile similarity. For GS, this is consistent with the differing effects of individual GS on the physiology and behaviour of insect herbivores, including specialists and generalists (Newton et al 2009;Hopkins et al 2009;Robin et al 2017).…”

“…Manuscript to be reviewed lability of GS profiles (Arany et al 2008;Bidart-Bouzat & Kliebenstein 2008;Gols et al 2008;Olsen et al 2016). Feeding by C. cardariae is not related to total GS concentration, but to overall GS profiles, consistent with the widely varying biological activity of individual GS (Newton et al 2009;Hopkins et al 2009;Robin et al 2017). Although three individual GS were correlated with C. cardariae feeding (propyl GS, butenyl, and 4-methylthiobutyl), the signs of these correlations differed and it is difficult to assign biological meaning with this dataset.…”

Simulated Herbivory: The Key to Disentangling Plant Defence Responses

“…Advantage 2: Eliminates the Effects of Tissue Quality It has been well documented that insects feed differentially based on the physical and chemical attributes of plant material [58][59][60][61], and therefore another major challenge associated with the use of true herbivory is the differential feeding patterns likely to be observed between treatments. Ryalls et al [58] showed that high concentrations of foliar silicon reduced herbivore feeding compared to leaves with lower amounts of silicon.…”

“…Ryalls et al [58] showed that high concentrations of foliar silicon reduced herbivore feeding compared to leaves with lower amounts of silicon. Robin et al [59] found diamondback moth (Plutella xylostella) larvae to feed preferentially on B.…”

Pre‐ and post‐ingestive defenses affect larval feeding on a lethal invasive host plant

“…The different consequences for larvae on the three host plant backgrounds emphasize the synergistic roles played by secondary plant chemistry in mediating larval feeding (Gershenzon et al, 2012;Robin et al, 2017). For example, larval feeding on D. incanagenerally considered to be the preferred and best-quality native host (Chew, 1975;Nakajima et al, 2013) was least affected by the addition of sinigrin.…”