Crystallization of α- and β-carotene in the foregut of Spodoptera larvae feeding on a toxic food plant.
In the animal kingdom, carotenoids are usually absorbed from dietary sources and transported to target tissues. Despite their general importance, the uptake mechanism is still poorly understood. Here we report the "red crop" phenomenon, an accumulation of α- and β-carotene in crystalline inclusions in the enlarged foregut of the polyphagous Spodoptera larvae feeding on some potentially toxic plant leaves. The carotene crystals give the insect foregut a distinctive orange-red color. The crystals are embedded in a homogenous lawn of the bacterium Enterococcus casseliflavus, but the carotene seems to be selectively taken from the food plant. Caterpillars which fail to develop these carotene crystals exhibit a high mortality or fail to develop to adulthood. The crystallization of carotene and the enlargement of the foregut thus appears to manifest a multiple-step physiological adaptation of the insects to toxic food plants.
Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, D-07745 Jena, Germany.
Yongqi
Y
Shao
Dieter
D
Spiteller
Xiaoshu
X
Tang
Liyan
L
Ping
Claudia
C
Colesie
Ute
U
Münchberg
Stefan
S
Bartram
Bernd
B
Schneider
Burkhard
B
Büdel
Jürgen
J
Popp
David G
DG
Heckel
Wilhelm
W
Boland
D000818:Animals; D002338:Carotenoids / Q000737:chemistry* / Q000378:metabolism*; D003460:Crystallization; D005247:Feeding Behavior; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000737:chemistry; D007814:Larva / Q000737:chemistry / Q000254:growth & development / Q000502:physiology; D010945:Plants, Edible / Q000469:parasitology*; D010947:Plants, Toxic / Q000469:parasitology*; D018411:Spodoptera / Q000737:chemistry / Q000254:growth & development / Q000502:physiology*; D019207:beta Carotene / Q000737:chemistry / Q000378:metabolism
D019207:beta Carotene; D002338:Carotenoids