Plant defence responses in oilseed rape MINELESS plants after attack by the cabbage moth Mamestra brassicae.
Bottom Line: No-choice feeding experiments showed that M. brassicae larvae gained less weight and showed stunted growth when feeding on MINELESS plants compared to feeding on wild-type plants.M. brassicae feeding didn't affect myrosinase activity in MINELESS plants, but did reduce it in wild-type seedlings.Taken together, the outcomes are very interesting in terms of analysing the role of myrosin cells and the glucosinolate-myrosinase defence system in response to a generalist cabbage moth, suggesting that similar studies with other generalist or specialist insect herbivores, including above- and below-ground herbivores, would be useful.
Affiliation: Department of Biology, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway.Show MeSH
Related in: MedlinePlus
License 1 - License 2
Mentions: Statistical analyses were performed using R language (R Development Core Team, 2011), and IBM SPSS Statistics version 20. Nonparametric tests were used, since data in general could not be assumed to be normally distributed (based on Anderson-Darling normality tests and quantile-quantile plots). For the no-choice experiments the differences between the insect weight gain of larvae retrieved from the wild-type and MINELESS plants on days 3, 7, 8, 10, and 12 were analysed using Wilcoxon Mann-Whitney tests, where P < 0.05 was considered significant. For the induction experiments, the levels of myrosinase activity, glucosinolates, and glucosinolate hydrolysis products among four different groups (wild-type control, wild-type M. brassicae, MINELESS control, and MINELESS M. brassicae) were analysed by a non-parametric version of one-way analysis of variance, the Kruskal-Wallis test (where P < 0.05 was considered significant); after being considered significant, they were followed by the pairwise Wilcoxon Mann-Whitney tests using Bonferroni post hoc correction (where P < 0.0083 is considered significant for six tests). For the myrosinase activity and gluconsinolates, only four observations were available in each group, and using a Wilcoxon Mann-Whitney test with two groups of four observations each (without ties), the smallest P-value that can be obtained is 0.02857, and thus in our data no pairwise comparisons could be found to be significant after Bonferroni correction (which requires P < 0.0083 when six comparisons are made). For the glucosinolate–myrosinase products, six observations were available in each group and the multicomView R-package (version 0.1–5) was used to categorize the four groups based on significance, as presented in Fig. 6 (http://cran.r-project.org/ and choose package multcompView).
Affiliation: Department of Biology, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway.