Feeding of turnip root fly (Delia floralis) and cabbage root fly (Delia radicum) larvae on Brassica napus L. transgenic MINELESS plants – Effects on insect development

Abstract

The dual component glucosinolate-myrosinase defence system is present in plants of the Brassicaceae. Upon insect attack, the defence system gets activated and forms glucosinolate hydrolysis products, which affect insect herbivory. The transgenic Brassica napus MINELESS plants have been produced by genetic ablation of myrosin cells, cells containing the myrosinase enzymes acting in the mustard bombs or toxic mines. In this study we analysed how the larvae of Delia radicum and D. floralis perform on wild-type and MINELESS B. napus plants and how these plants are affected. The larvae of both D. radicum and D. floralis gained more weight after feeding on MINELESS roots. Both aboveground and belowground plant biomass were observed to be higher for MINELESS plants compared to the wild-type on day 4 regardless of attack by D. radicum and D. floralis. We conclude that ablation of myrosin cells had a slight but not dramatic effect on the feeding behaviour for D. radicum and D. floralis.