Spatial organization of the glucosinolate-myrosinase system in brassica specialist aphids is similar to that of the host plant.
Secondary metabolites are important in plant defence against pests and diseases. Similarly, insects can use plant secondary metabolites in defence and, in some cases, synthesize their own products. The paper describes how two specialist brassica feeders, Brevicoryne brassicae (cabbage aphid) and Lipaphis erysimi (turnip aphid) can sequester glucosinolates (thioglucosides) from their host plants, yet avoid the generation of toxic degradation products by compartmentalizing myrosinase (thioglucosidase) into crystalline microbodies. We propose that death, or damage, to the insect by predators or disease causes disruption of compartmentalized myrosinase, which results in the release of isothiocyanate that acts as a synergist for the alarm pheromone E-beta-farnesene.
Bridges
Matthew
M
Department of Agricultural Sciences, Imperial College at Wye, University of London, Wye, Kent TN25 5AH, UK.
Jones
Alexandra M E
AM
Bones
Atle M
AM
Hodgson
Chris
C
Cole
Rosemary
R
Bartlet
Elspeth
E
Wallsgrove
Roger
R
Karapapa
Vassiliki K
VK
Watts
Nigel
N
Rossiter
John T
JT
D000818:Animals; D001042:Aphids / Q000378:metabolism* / Q000648:ultrastructure; D001937:Brassica / Q000378:metabolism*; D005961:Glucosinolates / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000378:metabolism*
D005961:Glucosinolates; C010330:sinigrin; D006026:Glycoside Hydrolases; C022739:thioglucosidase