Chapter 14 Plant-Allelochemical-Adapted Glutathione Transferases in Lepidoptera Downloaded by CALIFORNIA INST OF TECHNOLOGY on September 14, 2017 | http://pubs.acs.org Publication Date: September 22, 1992 | doi: 10.1021/bk-1992-0505.ch014
S. J. Yu Department of Entomology and Nematology, University of Florida, Gainesville, F L 32611
Glutathione transferases metabolized toxic allelochemicals, including α,β-unsaturated carbonyl compounds, isothiocyanates and organothiocyanates in lepidopterous insects. These transferase activities in the specialist velvetbean caterpillar are lower than i n the generalist fall armyworm; the activity toward the isothiocyanates in the crucifer-adapted cabbage looper was 2- to 6-fold higher than that i n the fall armyworm. Host plants such as crucifers and umbellifers, and allelochemicals such as coumarins, indoles, flavonoids, isothiocyanates and monoterpenes induced glutathione transferases in these insects. The highly polyphagous Lepidoptera, fall armyworm and corn earworm, possessed multiple glutathione transferases containing six and four isozymes, respectively, whereas the more specialized Lepidoptera, tobacco budworm, cabbage looper and velvetbean caterpillar, had a single form of the enzyme. The results suggest that glutathione transferases play an important role i n allelochemical resistance i n phytophagous Lepidoptera. G l u t a t h i o n e t r a n s f e r a s e s a r e a group o f d e t o x i c a t i o n enzymes c a t a l y z i n g t h e c o n j u g a t i o n o f g l u t a t h i o n e (GSH) with various xenobiotics possessing a reactive e l e c t r o p h i l i c center (1). Since the conjugates are subsequently transformed i n animals t o give excretable m e r c a p t u r i c a c i d s (2.) , g l u t a t h i o n e - d e p e n d e n t c o n j u g a t i o n has been r e g a r d e d as an i m p o r t a n t d e t o x i c a t i o n mechanism i n i n s e c t s a s w e l l a s i n mammals. These enzymes p e r f o r m a v a r i e t y o f r e a c t i o n s i n c l u d i n g (a) t h e S - a l k y l a t i o n o f
0097-6156y92y0505-O174$06.00/0 © 1992 American Chemical Society
Mullin and Scott; Molecular Mechanisms of Insecticide Resistance ACS Symposium Series; American Chemical Society: Washington, DC, 1992.
Downloaded by CALIFORNIA INST OF TECHNOLOGY on September 14, 2017 | http://pubs.acs.org Publication Date: September 22, 1992 | doi: 10.1021/bk-1992-0505.ch014
14. YU
Plant-Allelochemical-Adapted Glutathione Transferases
175
GSH by a l k y l h a 1 i d e s and r e l a t e d compounds; (b) t h e r e p l a c e m e n t o f l a b i l e a r y l h a l o g e n o r n i t r o g r o u p s by GSH; (c) t h e r e p l a c e m e n t o f l a b i l e a r a l k y l h a l o g e n by GSH; (d) t h e a d d i t i o n o f GSH t o v a r i o u s e p o x i d e s ; (e) the a d d i t i o n o f GSH t o a,6-unsaturated compounds i n c l u d i n g a l d e h y d e s , k e t o n e s , l a c t o n e s , n i t r i l e s and n i t r o compounds; a n d (f) t h e O - a l k y l and O - a r y l c o n j u g a t i o n o f p h o s p h o r o t h i o a t e s a n d p h o s p h a t e s w i t h GSH (2). Because of t h e i r broad substrate s p e c i f i c i t i e s , glutathione t r a n s f e r a s e s are r e s p o n s i b l e f o r the d e t o x i c a t i o n of numerous t o x i c a n t s . G l u t a t h i o n e t r a n s f e r a s e s are important i n the phase I I m e t a b o l i s m o f r e a c t i v e m e t a b o l i t e s f o r m e d by m i c r o s o m a l o x i d a t i o n s . They a r e a l s o i m p o r t a n t i n t h e p h a s e I m e t a b o l i s m o f o r g a n o p h o s p h o r u s i n s e c t i c i d e s (OP) and a r e b e l i e v e d t o p l a y a n i m p o r t a n t r o l e i n OP r e s i s t a n c e i n i n s e c t s ( 4 , 5 ) . O u r r e c e n t work h a s a l s o shown t h a t g l u t a t h i o n e t r a n s f e r a s e s a r e i n v o l v e d i n t h e metabolism of p o t e n t i a l l y t o x i c a l l e l o c h e m i c a l s i n c l u d i n g a , B - u n s a t u r a t e d c a r b o n y l compounds, i s o t h i o c y a n a t e s a n d organothiocyanates i n lepidopterous insects (6-8). E v i d e n c e a c c u m u l a t e d so f a r i n d i c a t e s t h a t g l u t a t h i o n e t r a n s f e r a s e s p l a y important r o l e s i n the d e t o x i c a t i o n of a l l e l o c h e m i c a l s and may be r e l a t e d t o h o s t p l a n t r a n g e i n phytophagous i n s e c t s . T h i s p a p e r r e v i e w s t h e c u r r e n t knowledge o f t h e b i o c h e m i c a l i n t e r a c t i o n s between g l u t a t h i o n e t r a n s f e r a s e s and a l l e l o c h e m i c a l s i n l e p i d o p t e r o u s s p e c i e s a n d p r e s e n t s experimental evidence suggesting that glutathione transferases play a significant role in allelochemical resistance i n these insects.
D e t o x i c a t i o n o f T o x i c A l l e l o c h e m i c a l s by G l u t a t h i o n e T r a n s f e r a s e s i n Lepidoptera Many a l l e l o c h e m i c a l s p o s s e s s s t r u c t u r a l r e q u i r e m e n t s t o s e r v e as s u b s t r a t e s f o r g l u t a t h i o n e t r a n s f e r a s e s . For example, the a , B - u n s a t u r a t e d c a r b o n y l moiety i s commonly f o u n d i n p l a n t c o n s t i t u e n t s s u c h a s c o u m a r i n s , q u i n o n e s , t e r p e n o i d s , c a r d e n o l i d e s , a l k a l o i d s , e t c . We found t h a t the a l l e l o c h e m i c a l s trans-cinnamaldehyde, trans-2-hexenal t r a n s , t r a n s - 2 , 4 - d e c a d i e n a l and b e n z a l d e h y d e were m e t a b o l i z e d by g l u t a t h i o n e t r a n s f e r a s e s f r o m t h e s o l u b l e f r a c t i o n o f t h e m i d g u t homogenates o f f a l l armyworm (FAW, S p o d o p t e r a f r u q i p e r d a ) l a r v a e with trans-cinnamaldehyde being a preferred substrate ( T a b l e I ) . U s i n g t r a n s - 4 - p h e n y 1 - 3 - b u t e n - 2 - o n e (TPBO) a s a m o d e l s u b s t r a t e , i t was f o u n d t h a t t h e TPBO t r a n s f e r a s e a c t i v i t y was d i f f e r e n t f r o m t h a t t o w a r d t h e m o d e l s u b s t r a t e 1 , 2 - d i c h l o r o - 4 - n i t r o b e n z e n e (DCNB) b a s e d on i t s d i s t r i b u t i o n p a t t e r n i n t h e p r o t e i n f r a c t i o n s i s o l a t e d b y ammonium s u l f a t e f r a c t i o n a t i o n o f t h e c y t o s o l (6). I n a d d i t i o n , p l a n t i s o t h i o c y a n a t e s were f o u n d t o be m e t a b o l i z e d by g l u t a t h i o n e t r a n s f e r a s e f r o m l e p i d o p t e r o u s f
Mullin and Scott; Molecular Mechanisms of Insecticide Resistance ACS Symposium Series; American Chemical Society: Washington, DC, 1992.
Mullin and Scott; Molecular Mechanisms of Insecticide Resistance ACS Symposium Series; American Chemical Society: Washington, DC, 1992.
a b
Adapted from Mean + S E .
r e f s . 6-8.
1 3 . 6 + 1.20
Benzyl
thiocyanate
95.0 ± 45.0 80.0 ± 30.0
0.70 0.46 0.67 0.48
A l l y l isothiocyanate Benzyl isothiocyanate
± ± ± +
4.67 10.05 3.59 4.08
Fall armyworm
16.6 + 4.00
57.0 + 20.0 170.0 ± 65.0
Cabbage looper
9.20 + 4.00
0 0
Velvetbean caterpillar
b
Glutathione transferase (nmol/min/mg p r o t e i n )
Glutathione transferase a c t i v i t y i n lepidopterous i n s e c t s toward p l a n t a l l e l o c h e m i c a l s *
Trans.trans-2,4-decadienal Trans.trans-cinnamaldehyde Benzaldehyde Trans-2-hexena1
Substrate
Table I .
Downloaded by CALIFORNIA INST OF TECHNOLOGY on September 14, 2017 | http://pubs.acs.org Publication Date: September 22, 1992 | doi: 10.1021/bk-1992-0505.ch014
Downloaded by CALIFORNIA INST OF TECHNOLOGY on September 14, 2017 | http://pubs.acs.org Publication Date: September 22, 1992 | doi: 10.1021/bk-1992-0505.ch014
14. YU Plant-AUelochemical-Adapted Glutathione Transferases
111
l a r v a e u s i n g t h e m i d g u t s o l u b l e f r a c t i o n a s t h e enzyme s o u r c e ( T a b l e I ) . A l l y l and b e n z y l i s o t h i o c y a n a t e s w e r e m e t a b o l i z e d by g l u t a t h i o n e t r a n s f e r a s e from t h e t w o g e n e r a l i s t s , t h e f a l l armyworm and cabbage l o o p e r ( C L , T r i c h o p l u s i a n i ) , b u t no a c t i v i t y was d e t e c t e d from t h e s p e c i a l i s t v e l v e t b e a n c a t e r p i l l a r (VBC, A n t i c a r s i a a e m m a t a l i s ) . The g e n e r a l i s t s , b u t n o t t h e s p e c i a l i s t , a r e a d a p t e d t o f e e d i n g on i s o t h i o c y a n a t e - c o n t a i n i n g c r u c i f e r s . The t r a n s f e r a s e a c t i v i t y t o w a r d t h e s e a l l e l o c h e m i c a l s i n t h e c r u c i f e r - a d a p t e d cabbage l o o p e r was 2 - t o 6 - f o l d h i g h e r t h a n t h a t i n t h e f a l l armyworm. The t r a n s f e r a s e s y s t e m o f f a l l armyworm a l s o metabolized 2 - p h e n y l e t h y l i s o t h i o c y a n a t e , but a c t i v i t y c a n o n l y be o b s e r v e d a f t e r i n d u c t i o n ( 7 ) . Data i n Table I a l s o demonstrated t h a t the o r g a n o t h i o c y a n a t e a l l e l o c h e m i c a l b e n z y l t h i o c y a n a t e was m e t a b o l i z e d by g l u t a t h i o n e t r a n s f e r a s e from l a r v a e o f t h r e e l e p i d o p t e r o u s s p e c i e s , t h e f a l l armyworm, c a b b a g e l o o p e r and v e l v e t b e a n c a t e r p i l l a r , u s i n g t h e m i d g u t s o l u b l e f r a c t i o n a s t h e enzyme s o u r c e . From T a b l e I I , i t c a n be s e e n t h a t t h e s e a , B u n s a t u r a t e d c a r b o n y l compounds, i s o t h i o c y a n a t e s and a n o r g a n o t h i o c y a n a t e were a l l t o x i c t o t h e f a l l armyworm, c a u s i n g a c u t e t o x i c i t y i n n e o n a t e s . Among t h o s e t e s t e d , b e n z y l and 2 - p h e n y l e t h y l i s o t h i o c y a n a t e s w e r e t h e most a c u t e l y t o x i c t o t h e armyworm. The i s o t h i o c y a n a t e s a n d t h e o r g a n o t h i o c y a n a t e were a l s o t o x i c t o o t h e r L e p i d o p t e r a s u c h as t h e v e l v e t b e a n c a t e r p i l l a r and cabbage l o o p e r ( 6 - 8 ) . P u r i f i c a t i o n and C h a r a c t e r i z a t i o n of G l u t a t h i o n e T r a n s f e r a s e s from Lepidoptera G l u t a t h i o n e t r a n s f e r a s e s have been p u r i f i e d and c h a r a c t e r i z e d i n numerous s p e c i e s o f i n s e c t s w i t h p a r t i c u l a r e m p h a s i s on t h e house f l y . M o l e c u l a r w e i g h t s of the g l u t a t h i o n e transferases studied are w i t h i n the r a n g e 3 5 , 0 0 0 - 6 3 , 0 0 0 . They c o n s i s t o f two s u b u n i t s (homodimers and h e t e r o d i m e r s ) o f m o l e c u l a r w e i g h t b e t w e e n 1 9 , 0 0 0 and 3 5 , 0 0 0 ( 9 ) . I n L e p i d o p t e r a , C l a r k g t a l . (10) were t h e f i r s t t o p u r i f y g l u t a t h i o n e t r a n s f e r a s e from a l e p i d o p t e r o u s i n s e c t , t h e g r e a t e r wax moth ( G a l l e r i a m e l l o n e l l a ) , u s i n g a f f i n i t y c h r o m a t o g r a p h y on g l u t a t h i o n e - s u l f o b r o m o p h t h a l e i n - a g a r o s e . Because o f i t s s e l e c t i v e a b i l i t y to bind with glutathione transferase, t h i s enzyme was i s o l a t e d from t h i s s p e c i e s i n s u b s t a n t i a l l y p u r e f o r m . The t r a n s f e r a s e h a d a m o l e c u l a r w e i g h t o f 4 1 , 0 0 0 w i t h two s u b u n i t s o f M 2 5 , 0 0 0 . I t s s u b s t r a t e s p e c i f i c i t y was f o u n d t o r e s e m b l e t h a t o f t h e g l u t a t h i o n e t r a n s f e r a s e B from r a t l i v e r ( 1 1 ) . S e v e r a l g l u t a t h i o n e t r a n s f e r a s e s from t h e p o r i n a moth ( W i s e a n a c e r v i n a t a ) were p u r i f i e d by a f f i n i t y c h r o m a t o g r a p h y , c a t i o n - e x c h a n g e c h r o m a t o g r a p h y and p r e p a r a t i v e i s o e l e c t r o f o c u s i n g (12) . The m a j o r r
Mullin and Scott; Molecular Mechanisms of Insecticide Resistance ACS Symposium Series; American Chemical Society: Washington, DC, 1992.
Downloaded by CALIFORNIA INST OF TECHNOLOGY on September 14, 2017 | http://pubs.acs.org Publication Date: September 22, 1992 | doi: 10.1021/bk-1992-0505.ch014
178
MOLECULAR MECHANISMS OF INSECTICIDE RESISTANCE
Table I I .
T o x i c i t y of a l l e l o c h e m i c a l s t o neonate armyworm l a r v a e * *
fall
b
Allelochemical
a b
c
L C
50
C
Trans,trans-2,4-decadienal Trans-cinnamaldehyde Benzaldehyde Trans-2-hexenal
0.033 0.077 0.089 0.214
A l l y l isothiocyanate Benzyl isothiocyanate 2-Phenylethyl isothiocyanate
0.017 0.006 0.006
Benzyl thiocyanate
0.041
A d a p t e d from r e f s . 6 - 8 . G r o u p s o f 20 n e o n a t e l a r v a e were f e d a r t i f i c i a l d i e t c o n t a i n i n g a l l e l o c h e m i c a l s f o r 24 h r b e f o r e m o r t a l i t y c o u n t s were made. % i n d i e t (w/w).
Mullin and Scott; Molecular Mechanisms of Insecticide Resistance ACS Symposium Series; American Chemical Society: Washington, DC, 1992.
14. YU Plant-AUelochemical-Adapted Glutathione Transferases
179
t r a n s f e r a s e was p u r i f i e d t o h o m o g e n e i t y by a f a c t o r o f 5 3 0 - f o l d . The m o l e c u l a r w e i g h t s o f t h e s e t r a n s f e r a s e s w e r e e s t i m a t e d t o be 4 5 , 0 0 0 - 5 0 , 0 0 0 . They a p p e a r e d t o be homodimers o f e i t h e r o f two t y p e s o f s u b u n i t s o f M 22,800 and 2 4 , 6 0 0 . G l u t a t h i o n e t r a n s f e r a s e from t h e d i a m o n d b a c k moth ( P l u t e l l a x y l o s t e l l a ) was p u r i f i e d by e i t h e r t h e t r a d i t i o n a l method i n v o l v i n g ammonium s u l f a t e f r a c t i o n a t i o n , g e l f i l t r a t i o n and h y d r o x y a p a t i t e c h r o m a t o g r a p h y o r by a f f i n i t y c h r o m a t o g r a p h y ( G S H s u l f o b r o m o p h t h a l e i n - a g a r o s e ) . The n a t i v e g l u t a t h i o n e t r a n s f e r a s e h a d m o l e c u l a r w e i g h t s o f 4 5 , 0 0 0 - 4 6 , 5 0 0 . The p u r i f i e d t r a n s f e r a s e a c t i v i t y t o w a r d DCNB i n t h e i n s e c t i c i d e r e s i s t a n t s t r a i n was h i g h e r t h a n i n t h e s u s c e p t i b l e s t r a i n (13.) . T h a t t h i s s p e c i e s p o s s e s s e d a s i n g l e f o r m o f t h e enzyme was c o n f i r m e d by B a l a b a s k a r a n e t a l . (14) who u s e d i o n - e x c h a n g e c h r o m a t o g r a p h y (DEAESephadex A - 5 0 and CM-Sephadex C-50) and a d s o r p t i o n c h r o m a t o g r a p h y ( B i o - G e l HTP h y d r o x y a p a t i t e ) . A c c o r d i n g t o t h e s e a u t h o r s , the p u r i f i e d g l u t a t h i o n e t r a n s f e r a s e had an i s o e l e c t r i c p o i n t o f 9 . 2 6 and a m o l e c u l a r w e i g h t o f 36,400. G l u t a t h i o n e t r a n s f e r a s e s from l a r v a e o f t h e s u g a r b o r e r ( D i a t r a e a s a c c h a r a l i s ) and t h e M e x i c a n r i c e b o r e r (Eoreuma l o f t n i ) w e r e p u r i f i e d by G S H - a f f i n i t y c h r o m a t o g r a p h y and i s o e l e c t r i c f o c u s i n g ( 1 5 ) . Two g l u t a t h i o n e t r a n s f e r a s e s were p u r i f i e d f r o m s u g a r b o r e r l a r v a e . The i s o z y m e w i t h a p i v a l u e o f 9 . 3 was a homodimer o f two s u b u n i t s o f M 2 5 , 0 0 0 , w h e r e a s t h e i s o z y m e w i t h a p i v a l u e o f 8 . 0 was a h e t e r o d i m e r o f s u b u n i t s h a v i n g M 2 5 , 0 0 0 and 2 7 , 0 0 0 . On t h e o t h e r h a n d , t h r e e g l u t a t h i o n e t r a n s f e r a s e s were p u r i f i e d f r o m M e x i c a n r i c e b o r e r l a r v a e . The i s o z y m e s w i t h p i v a l u e s o f 9 . 7 a n d 7 . 7 w e r e homodimers o f s u b u n i t s w i t h M 2 5 , 0 0 0 a n d 2 6 , 0 0 0 , r e s p e c t i v e l y . However, t h e isozyme w i t h a p i v a l u e o f 5 . 3 was a h e t e r o d i m e r o f s u b u n i t s h a v i n g M 26,000 and 2 7 , 0 0 0 . P e p t i d e f i n g e r p r i n t a n a l y s i s r e v e a l e d primary s t r u c t u r a l differences i n these isozymes. We h a v e r e c e n t l y p u r i f i e d and c h a r a c t e r i z e d g l u t a t h i o n e t r a n s f e r a s e s from f i v e s p e c i e s o f L e p i d o p t e r a w i t h d i f f e r i n g d e g r e e s o f p o l y p h a g y . The f a l l armyworm and c o r n earworm (CEW, H e l i c o v e r p a zea) a r e h i g h l y p o l y p h a g o u s i n s e c t s . The t o b a c c o budworm (TBW, H e l i o t h i s v i r e s c e n s ) and c a b b a g e l o o p e r a r e a l s o p o l y p h a g o u s i n s e c t s b u t a r e more s p e c i a l i z e d . The f o r m e r f e e d s m a i n l y on t o b a c c o and c o t t o n , w h i l e t h e l a t t e r p r e f e r e n t i a l l y f e e d s on p l a n t s i n t h e cabbage f a m i l y . The v e l v e t b e a n c a t e r p i l l a r i s a s p e c i a l i s t i n s e c t f e e d i n g m a i n l y on c e r t a i n s p e c i e s o f legumes. We h a v e f o u n d t h a t g l u t a t h i o n e t r a n s f e r a s e s c a n be p u r i f i e d from t h e s e l e p i d o p t e r o u s i n s e c t s t o apparent h o m o g e n e i t y u s i n g a t w o - s t e p p r o c e d u r e i n v o l v i n g ammonium s u l f a t e f r a c t i o n a t i o n and a f f i n i t y c h r o m a t o g r a p h y on a g l u t a t h i o n e - a g a r o s e column ( 1 6 ) . P u r i f i c a t i o n s were 22, 4 5 , 3 7 , 9 and 3 3 - f o l d i n t h e FAW, CEW, TBW, CL and V B C ,
Downloaded by CALIFORNIA INST OF TECHNOLOGY on September 14, 2017 | http://pubs.acs.org Publication Date: September 22, 1992 | doi: 10.1021/bk-1992-0505.ch014
r
r
r
r
r
Mullin and Scott; Molecular Mechanisms of Insecticide Resistance ACS Symposium Series; American Chemical Society: Washington, DC, 1992.
Downloaded by CALIFORNIA INST OF TECHNOLOGY on September 14, 2017 | http://pubs.acs.org Publication Date: September 22, 1992 | doi: 10.1021/bk-1992-0505.ch014
180
MOLECULAR MECHANISMS OF INSECTICIDE RESISTANCE
r e s p e c t i v e l y , a s compared w i t h t h e s p e c i f i c a c t i v i t y i n t h e r e s p e c t i v e s o l u b l e f r a c t i o n ( T a b l e I I I ) . The s p e c i f i c a c t i v i t y of the p u r i f i e d g l u t a t h i o n e transferases ranged f r o m 2 . 2 9 /xmol/min/mg p r o t e i n i n t h e VBC t o 5 8 . 3 5 /xmol/min/mg p r o t e i n i n t h e CEW, a d i f f e r e n c e o f 2 5 - f o l d i n enzyme a c t i v i t y . The b i o c h e m i c a l c h a r a c t e r i s t i c s o f p u r i f i e d g l u t a t h i o n e t r a n s f e r a s e s from t h e f i v e l e p i d o p t e r o u s s p e c i e s a r e shown i n T a b l e I V . A n a l y s i s o f t h e a f f i n i t y p u r i f i e d p r e p a r a t i o n s by p o l y a c r y l a m i d e g e l e l e c t r o p h o r e s i s (PAGE) u n d e r n o n d e n a t u r i n g c o n d i t i o n s r e v e a l e d t h e p r e s e n c e o f 6, 4 , 1, 1 and 1 p r o t e i n s p e c i e s i n t h e FAW, CEW, TBW, CL and VBC, r e s p e c t i v e l y . T h e s e p r o t e i n s p e c i e s were r e g a r d e d as g l u t a t h i o n e t r a n s f e r a s e i s o z y m e s s i n c e e a c h band c a t a l y z e d g l u t a t h i o n e c o n j u g a t i o n w i t h CDNB. When t h e p r e p a r a t i o n s were a n a l y z e d by i s o e l e c t r i c f o c u s i n g i n p o l y a c r y l a m i d e g e l s , t h e same number o f p r o t e i n bands a s f o u n d i n PAGE a r e a l s o o b s e r v e d i n e a c h s p e c i e s . The p i v a l u e s r a n g e d f r o m 4 . 4 5 t o 6 . 0 0 among t h e f i v e s p e c i e s , i n d i c a t i n g t h a t t h e s e t r a n s f e r a s e s were a l l a c i d i c i s o z y m e s . SDS-PAGE o f t h e p u r i f i e d enzymes showed 4 , 3 , 3 , 2 and 2 p r o t e i n b a n d s i n t h e FAW, CEW, TBW, CL and VBC, r e s p e c t i v e l y . The s u b u n i t m o l e c u l a r w e i g h t s r a n g e d from 2 7 , 0 0 0 t o 3 2 , 0 0 0 w i t h t h e s u b u n i t ( M 29,000) b e i n g found i n each s p e c i e s . Since i n s e c t g l u t a t h i o n e transferases e x i s t i n dimers (homodimers a n d h e t e r o d i m e r s ) ( 9 ) , t h e m o l e c u l a r w e i g h t s of the n a t i v e g l u t a t h i o n e t r a n s f e r a s e s would l i k e l y range f r o m 5 5 , 0 0 0 t o 6 4 , 0 0 0 b a s e d on t h e i r s u b u n i t m o l e c u l a r w e i g h t s . I t i s n o t known why t h e TBW, w h i c h p o s s e s s e d a s i n g l e f o r m o f g l u t a t h i o n e t r a n s f e r a s e , showed t h r e e s u b u n i t s i n S D S - P A G E . The p o s s i b i l i t y e x i t s t h a t one o f t h e s u b u n i t s may h a v e been an a r t i f a c t r e s u l t i n g f r o m d e g r a d a t i o n o f t h e enzyme. K i n e t i c s t u d i e s showed t h a t t h e p u r i f i e d g l u t a t h i o n e t r a n s f e r a s e s among t h e s e i n s e c t s were q u a l i t a t i v e l y L d i f f e r e n t b a s e d on t h e i r K v a l u e s e x c e p t f o r t h e e q u i v a l e n t K s o f CEW and TBW. T h a t g l u t a t h i o n e transferases are q u a l i t a t i v e l y d i f f e r e n t i n the f i v e s p e c i e s was a l s o s u p p o r t e d by t h e r e s u l t s o b t a i n e d f r o m t h e enzyme i n h i b i t i o n s t u d y . A s shown i n T a b l e I V , t h e TBW g l u t a t h i o n e t r a n s f e r a s e was most s e n s i t i v e t o i n h i b i t i o n b y q u e r c e t i n , f o l l o w e d by CEW, C L , FAW a n d VBC. I t h a s r e c e n t l y been d e m o n s t r a t e d f o r h o u s e f l i e s t h a t some g l u t a t h i o n e t r a n s f e r a s e i s o z y m e s p o s s e s s i n g DCNB a c t i v i t y do n o t n e c e s s a r i l y b i n d t o G S H - a g a r o s e ( C l a r k e t a l . , P r o t e i n E x p r e s s i o n and P u r i f i c a t i o n , i n p r e s s ) . Therefore, the p o s s i b i l i t y of the presence of o t h e r i s o z y m e s i n t h e s e l e p i d o p t e r o u s s p e c i e s c a n n o t be ruled out. r
m
m
Mullin and Scott; Molecular Mechanisms of Insecticide Resistance ACS Symposium Series; American Chemical Society: Washington, DC, 1992.
Mullin and Scott; Molecular Mechanisms of Insecticide Resistance ACS Symposium Series; American Chemical Society: Washington, DC, 1992.
VBC
CL
TBW
CEW
FAW
b
a
Species
Adapted from r e f . Mean ± S E .
16.
Cytosolic fraction Ammonium s u l f a t e (45-75%) GSH-agarose Cytosolic fraction Ammonium s u l f a t e GSH-agarose Cytosolic fraction Ammonium s u l f a t e GSH-agarose Cytosolic fraction Ammonium s u l f a t e GSH-agarose Cytosolic fraction Ammonium s u l f a t e GSH-agarose
0.47 1.05 10.37 1.30 1.93 58.35 0.47 1.41 17.50 1.35 2.73 12.16 0.07 0.11 2.29
69 12 100 80 8 100 62 10 100 69 3 100 54 26
+ + + + + + + + + + + + + +
0.13 1.49 0.04 0.08 2.29 0.10 0.09 3.72 0.27 0.47 1.86 0.01 0.07 0.33
+ 0.06
b
Specific activity (/imol CDNB/min/mg protein)
100
Yield (%)
2.2 22.1 1.0 1.5 44.9 1.0 3.0 37.2 1.0 2.0 9.0 1.0 1.6 32.9
1.0
Purification factor
P u r i f i c a t i o n of g l u t a t h i o n e t r a n s f e r a s e s from f i v e lepidopterous i n s e c t s *
Purification step
Table I I I .
Downloaded by CALIFORNIA INST OF TECHNOLOGY on September 14, 2017 | http://pubs.acs.org Publication Date: September 22, 1992 | doi: 10.1021/bk-1992-0505.ch014
Mullin and Scott; Molecular Mechanisms of Insecticide Resistance ACS Symposium Series; American Chemical Society: Washington, DC, 1992.
K
ra
0.40
0.40
0.56 9.09
CEW
TBW
CL VBC
12.5 18.2
50.0
50.0
17.2
Vmax (/xmol/min/ mg p r o t e i n )
22 100
0
0
23
D
46 100
0
12
71
10~ M
32,000 29,000 27,500 31,000 31,000 29,000
32,000 29,000 27,500
30,000 29,500 29,000 28,200
r
Subunit M
SOURCE: Reprinted with permissionfromref. 16. Copyright 1989 Academic.
5.10 4.85
6.0 5.10 5.00 4.75 4.55 4.45 5.10 5.05 4.90 4.75 5.45
PI
enzyme
0.53 0.44
0.34 0.42 0.46 0.51 0.55 0.59 0.38 0.42 0.46 0.54 0.47
Isozyme (Rf)
f r o m e a c h s p e c i e s was u s e d a s
10~* M
I n h i b i t i o n by quercetin (% o f c o n t r o l )
Biochemical c h a r a c t e r i s t i c s o f p u r i f i e d g l u t a t h i o n e t r a n s f e r a s e s from f i v e lepidopterous i n s e c t s *
A f f i n i t y purified preparation s o u r c e t o w a r d CDNB.
1.33
(mM)
FAW
Species
T a b l e IV.
Downloaded by CALIFORNIA INST OF TECHNOLOGY on September 14, 2017 | http://pubs.acs.org Publication Date: September 22, 1992 | doi: 10.1021/bk-1992-0505.ch014
14. YU Plant-Allelochemical-Adapted Glutathione Transferases
183
Downloaded by CALIFORNIA INST OF TECHNOLOGY on September 14, 2017 | http://pubs.acs.org Publication Date: September 22, 1992 | doi: 10.1021/bk-1992-0505.ch014
I n d u c t i o n o f G l u t a t h i o n e Transferases by A l l e l o c h e m i c a l s i n Lepidoptera G l u t a t h i o n e t r a n s f e r a s e s a r e i n d u c e d by x e n o b i o t i c s s u c h a s b a r b i t u r a t e s and p e s t i c i d e s i n mammals (17) and i n i n s e c t s . O t t e a and P l a p p (18) f o u n d t h a t g l u t a t h i o n e t r a n s f e r a s e was i n d u c e d n e a r l y 3 - f o l d i n h o u s e f l i e s by d i e t a r y p h e n o b a r b i t a l . H a y a o k a and Dauterman (19) a l s o o b t a i n e d i n d u c t i o n i n house f l i e s by v a r i o u s d i e t a r y i n s e c t i c i d e s w i t h c h l o r i n a t e d h y d r o c a r b o n s b e i n g most a c t i v e . More r e c e n t l y , Capua e t a l . (20) h a v e demonstrated i n d u c t i o n of g l u t a t h i o n e transferase i n the b u l b m i t e ( R h i z o q l y p h u s r o b i n i ) by numerous x e n o b i o t i c s , i n c l u d i n g p e n t o b a r b i t a l and t h e i n s e c t i c i d e s f e n p r o p a t h r i n and p r o p o x u r . Glutathione transferases i n lepidopterous insects a r e i n d u c e d by numerous h o s t p l a n t s . U m b e l l i f e r s and c r u c i f e r s w e r e b e t t e r i n d u c e r s o f t h e s e enzymes t h a n o t h e r p l a n t s s c r e e n e d ( T a b l e V ) . P a r s n i p was t h e b e s t i n d u c e r among t h o s e t e s t e d , c a u s i n g a 3 9 - f o l d i n c r e a s e compared w i t h a c t i v i t y i n l a r v a e f e d a r t i f i c i a l d i e t . However, p l a n t s such as soybeans, sorghum, m i l l e t , B e r m u d a g r a s s , c o r n , p o t a t o , c u c u m b e r , c a r r o t and b r o c c o l i h a d no e f f e c t on t h i s enzyme (21,22.) . Time c o u r s e s t u d i e s showed t h a t t h e maximum i n d u c t i o n o f t h e t r a n s f e r a s e by cowpeas o c c u r r e d two d a y s a f t e r f e e d i n g began ( 2 1 ) . The m e t h a n o l l e a f e x t r a c t o f a r e s i s t a n t s o y b e a n v a r i e t y (PI227687) i n d u c e d g l u t a t h i o n e t r a n s f e r a s e i n the soybean l o o p e r ( P s e u d o p l u s i a includens) (23). Induction of glutathione transferases also occurs i n d e c i d u o u s t r e e - f e e d i n g i n s e c t s . L i n d r o t h (24.) f o u n d t h a t g l u t a t h i o n e t r a n s f e r a s e a c t i v i t i e s i n t h e l u n a moth ( A c t i a s l u n a ) l a r v a e f e d b l a c k w a l n u t , b u t t e r n u t and s h a g b a r k h i c k o r y were 2 t o 3 - f o l d h i g h e r t h a n i n those fed paper b i r c h . Furthermore, microsomal g l u t a t h i o n e t r a n s f e r a s e a c t i v i t y v a r i e d up t o 5 - f o l d among e a s t e r n t i g e r s w a l l o w t a i l ( P a p i l i o g l a u c u s glaucus) l a r v a e fed b l a c k c h e r r y , t u l i p t r e e , paper b i r c h , w h i t e a s h and basswood (2j>) . The i n d u c t i o n i s b e l i e v e d t o be due t o a l l e l o c h e m i c a l s i n t h e p l a n t s . The i d e n t i t y o f t h e g l u t a t h i o n e t r a n s f e r a s e i n d u c e r i n p a r s n i p l e a v e s was d e t e r m i n e d by t h i n - l a y e r c h r o m a t o g r a p h y , h i g h - p r e s s u r e l i q u i d c h r o m a t o g r a p h y , g a s c h r o m a t o g r a p h y , and mass s p e c t r o m e t r y as x a n t h o t o x i n , a l i n e a r furanocoumarin (26). O t h e r a l l e l o c h e m i c a l s such as i n d o l e 3 a c e t o n i t r i l e , i n d o l e 3 - c a r b i n o l , i n d o l e 3-B-D g l u c o s i d e , flavone, a l l y l isothiocyanate, benzyl isothiocyanate, 2p h e n y l e t h y l i s o t h i o c y a n a t e , b e n z y l t h i o c y a n a t e and s i n i g r i n a l s o i n d u c e d t h e t r a n s f e r a s e i n f a l l armyworms (Table V ) . Xanthotoxin a l s o induced g l u t a t h i o n e transferase i n the black s w a l l o w t a i l ( P a p i l i o polyxenes) and c a b b a g e l o o p e r and h a r m i n e , an i n d o l e a n a l o g , i n d u c e d t h e t r a n s f e r a s e i n t h e cabbage l o o p e r ( 2 7 ) .
Mullin and Scott; Molecular Mechanisms of Insecticide Resistance ACS Symposium Series; American Chemical Society: Washington, DC, 1992.
Downloaded by CALIFORNIA INST OF TECHNOLOGY on September 14, 2017 | http://pubs.acs.org Publication Date: September 22, 1992 | doi: 10.1021/bk-1992-0505.ch014
184
MOLECULAR MECHANISMS OF INSECTICIDE RESISTANCE
I n a d d i t i o n , d i e t a r y c o u m a r i n and m o n o t e r p e n e s (cepinene, B-pinene, limonene, terpinene) induced g l u t a t h i o n e t r a n s f e r a s e i n s o u t h e r n armyworm ( S p o d o p t e r a e r i d a n i a ) l a r v a e (2IL) . H o w e v e r , m o n o t e r p e n e s were n o t i n d u c e r s o f t h e t r a n s f e r a s e i n f a l l armyworm l a r v a e (21) • C o u m e s t r o l , a coumarin analog found i n a r e s i s t a n t soybean c u l t i v a r , induced g l u t a t h i o n e t r a n s f e r a s e i n s o y b e a n l o o p e r s (22.) • 2 - T r i d e c a n o n e f o u n d i n w i l d t o m a t o l e a v e s i n d u c e d g l u t a t h i o n e t r a n s f e r a s e i n t o b a c c o budworm larvae (30). K i n e t i c s t u d y r e v e a l e d a q u a n t i t a t i v e , b u t no q u a l i t a t i v e d i f f e r e n c e between t h e g l u t a t h i o n e t r a n s f e r a s e o f s o y b e a n - and c o w p e a - f e d f a l l armyworms ( 2 1 ) . These r e s u l t s support the n o t i o n t h a t t h e s e i n d u c e d t r a n s f e r a s e s a r e n o t s e p a r a t e i s o z y m e s . Our r e c e n t w o r k also i n d i c a t e d that induction of glutathione transferase i n f a l l armyworm l a r v a e by x a n t h o t o x i n i n c r e a s e d l e v e l s of the e x i s t i n g isozymes but d i d not r e s u l t i n p r o d u c t i o n o f a new i s o z y m e ( 1 6 ) . G l u t a t h i o n e t r a n s f e r a s e s toward the t o x i c a l l e l o c h e m i c a l s trans-cinnamaldehyde. benzaldehyde, a l l y l i s o t h i o c y a n a t e , b e n z y l i s o t h i o c y a n a t e and b e n z y l t h i o c y a n a t e c a n be i n d u c e d by v a r i o u s a l l e l o c h e m i c a l s i n c l u d i n g r e s p e c t i v e s u b s t r a t e s ( T a b l e V I ) . Hence a l l e l o c h e m i c a l i n d u c t i o n o f i t s own m e t a b o l i s m c a n o c c u r i n p h y t o p h a g o u s i n s e c t s . However, x a n t h o t o x i n , a p o t e n t i n d u c e r o f t h e enzyme, was n o t m e t a b o l i z e d by g l u t a t h i o n e t r a n s f e r a s e f r o m l a r v a e o f t h e f a l l armyworm (6) a n d b l a c k s w a l l o w t a i l (27) . U s i n g t w o a l l e l o c h e m i c a l s , x a n t h o t o x i n and i n d o l e 3 a c e t o n i t r i l e , as i n d u c e r s o f g l u t a t h i o n e t r a n s f e r a s e ( t o w a r d DCNB), m a r g i n a l i n d u c t i o n (16-39%) was f o u n d i n t h e s p e c i a l i s t VBC compared t o 1580-2544% i n t h e g e n e r a l i s t FAW ( F i g u r e 1 ) . Enzyme a s s a y s i n i n d i v i d u a l l a r v a e showed t h a t i n d u c i b i l i t y o f g l u t a t h i o n e t r a n s f e r a s e v a r i e d considerably i n the populations of the s p e c i a l i s t and g e n e r a l i s t s p e c i e s ( F i g u r e s 2 and 3 ) . A l l i n d i v i d u a l s w e r e i n d u c e d i n t h e FAW p o p u l a t i o n c o m p a r e d t o o n l y one t h i r d o f t h e VBC p o p u l a t i o n b e i n g i n d u c e d . M o r e o v e r , t h e n e t i n c r e a s e i n enzyme a c t i v i t y due t o i n d u c t i o n was much h i g h e r i n t h e FAW t h a n i n t h e V B C . The o b s e r v e d d i f f e r e n c e s i n enzyme i n d u c i b i l i t y c o u l d be a t t r i b u t e d t o t h e q u a l i t a t i v e a s w e l l as q u a n t i t a t i v e d i f f e r e n c e s i n g l u t a t h i o n e t r a n s f e r a s e isozymes i n these species. Role o f G l u t a t h i o n e T r a n s f e r a s e s i n Insect Herbivory As mentioned above, g l u t a t h i o n e t r a n s f e r a s e s a r e i n v o l v e d i n the i n v i t r o metabolism of t o x i c a l l e l o c h e m i c a l s i n p h y t o p h a g o u s L e p i d o p t e r a . The a l l e l o c h e m i c a l s t r a n s cinnamaldehyde, trans-hexena1, trans,trans-2,4d e c a d i e n a l and b e n z a l d e h y d e , a l l o f w h i c h c o n t a i n t h e a,B-unsaturated c a r b o n y l m o i e t y , were m e t a b o l i z e d by g l u t a t h i o n e t r a n s f e r a s e from m i d g u t homogenates o f FAW.
Mullin and Scott; Molecular Mechanisms of Insecticide Resistance ACS Symposium Series; American Chemical Society: Washington, DC, 1992.
14. YU Plant-Allelochemical-Adapted Glutathione Transferases Table V.
Glutathione t r a n s f e r a s e a c t i v i t y o f f a l l armyworm l a r v a e f e d host p l a n t s and a l l e l o c h e m i c a l s *
Downloaded by CALIFORNIA INST OF TECHNOLOGY on September 14, 2017 | http://pubs.acs.org Publication Date: September 22, 1992 | doi: 10.1021/bk-1992-0505.ch014
Inducer
a
Glutathione transferase (% o f a r t i f i c i a l d i e t - f e d
Cotton Peanuts C h i n e s e cabbage Cabbage Collards Cowpeas Radish Turnip Mustard Parsley Parsnip
142 179 221 404 472 493 636 731 782 1944 3909
I n d o l e 3 - a c e t o n i t r i l e (0.2%) I n d o l e 3 - c a r b i n o l (0.2%) I n d o l e 3 - B - D - g l u c o s i d e (0.2%) F l a v o n e (0.2%) S i n i g r i n (0.2%) 2 - P h e n y l e t h y l i s o t h i o c y a n a t e (0.025%) X a n t h o t o x i n (0.01%)
1801 388 202 687 342 217 2644
Adapted from r e f s .
—
185
(DCNB) insects)
2 1 , 22 a n d 2 6 .
3.000
c
VBC
FAW
Xanthotoxin (0.01%)
VBC
FAW
Indole 3-acetonitrile (0.1-0.2%)
F i g . 1. Induction of glutathione transferase a c t i v i t y by a l l e l o c h e m i c a l s i n v e l v e t b e a n c a t e r p i l l a r a n d f a l l armyworm l a r v a e . Mullin and Scott; Molecular Mechanisms of Insecticide Resistance ACS Symposium Series; American Chemical Society: Washington, DC, 1992.
Mullin and Scott; Molecular Mechanisms of Insecticide Resistance ACS Symposium Series; American Chemical Society: Washington, DC, 1992.
13
237
249
Benzaldehyde
542
1092 550 625 558
Allyl isothiocyanate
1006
550
Benzyl isothiocyanate
162
515 412 426 456
Adapted from r e f s . 6 - 8 . N e w l y m o l t e d s i x t h - i n s t a r l a r v a e were f e d a r t i f i c i a l d i e t s c o n t a i n i n g t h e a l l e l o c h e m i c a l s (0.2%, u n l e s s o t h e r w i s e s t a t e d ) f o r t w o d a y s b e f o r e enzyme a s s a y s were c o n d u c t e d .
93
217
218
Transcinnamaldehyde
Benzyl thiocyanate
transferase larvae*
Glutathione transferase with substrate (% o f c o n t r o l a c t i v i t y )
E f f e c t o f d i e t a r y a l l e l o c h e m i c a l s on g l u t a t h i o n e a c t i v i t y toward a l l e l o c h e m i c a l s i n f a l l armyworm
Indole 3 - a c e t o n i t r i l e Indole 3-carbinol Flavone X a n t h o t o x i n (0.01%) T r a n s - c innamaldehyde Benzaldehyde A l l y l isothiocyanate (0.025%) Benzyl isothiocyanate (0.025%) Benzyl thiocyanate
Treatment
Table V I .
Downloaded by CALIFORNIA INST OF TECHNOLOGY on September 14, 2017 | http://pubs.acs.org Publication Date: September 22, 1992 | doi: 10.1021/bk-1992-0505.ch014
Downloaded by CALIFORNIA INST OF TECHNOLOGY on September 14, 2017 | http://pubs.acs.org Publication Date: September 22, 1992 | doi: 10.1021/bk-1992-0505.ch014
14. YU
Plant-AUelochemical-Adapted Glutathione Transferases
40
Control 16
12
8
-
8
LL
Xanthotoxin (0.01%)
0
0.4
0.8
1.2
1.6
2.0
2.4
Glutathione transferase (nmol/min/larva)
F i g . 2. Histograms f o r g l u t a t h i o n e t r a n s f e r a s e a c t i v i t y (DCNB) i n i n d i v i d u a l larvae of the f a l l armyworm f e d xanthotoxin (0.01%) (Yu, S. J . J . Econ. Entomol.. i n p r e s s ) .
Mullin and Scott; Molecular Mechanisms of Insecticide Resistance ACS Symposium Series; American Chemical Society: Washington, DC, 1992.
187
Downloaded by CALIFORNIA INST OF TECHNOLOGY on September 14, 2017 | http://pubs.acs.org Publication Date: September 22, 1992 | doi: 10.1021/bk-1992-0505.ch014
MOLECULAR MECHANISMS OF INSECTICIDE RESISTANCE
16
-
Control 12
8
-
o c
D WMMM.mM Indole 3-acetonitrile (0.1%)
0
20
40
60
80
100
Glutathione transferase (nmol/min/larva) F i g . 3. H i s t o g r a m s f o r g l u t a t h i o n e t r a n s f e r a s e a c t i v i t y (DCNB) i n i n d i v i d u a l l a r v a e o f t h e velvetbean c a t e r p i l l a r fed i n d o l e 3 - a c e t o n i t r i l e (0.1%).
Mullin and Scott; Molecular Mechanisms of Insecticide Resistance ACS Symposium Series; American Chemical Society: Washington, DC, 1992.
Downloaded by CALIFORNIA INST OF TECHNOLOGY on September 14, 2017 | http://pubs.acs.org Publication Date: September 22, 1992 | doi: 10.1021/bk-1992-0505.ch014
14. YU
Plant-AUelochemical-Adapted Glutathione Transferases
189
I s o t h i o c y a n a t e s s u c h a s a l l y l , b e n z y l and 2 - p h e n y l e t h y l i s o t h i o c y a n a t e s and o r g a n o t h i o c y a n a t e s s u c h a s b e n z y l t h i o c y a n a t e w e r e m e t a b o l i z e d by g l u t a t h i o n e t r a n s f e r a s e f r o m l a r v a e o f t h e FAW, CL and V B C . F u r t h e r m o r e , numerous a l l e l o c h e m i c a l s induced glutathione transferase a c t i v i t y w h i c h i s p r e s u m e d t o enhance t h e d e t o x i c a t i o n o f a l l e l o c h e m i c a l s . In a d d i t i o n , glutathione transferase a c t i v i t y t o w a r d v a r i o u s a l l e l o c h e m i c a l s was l o w e r i n t h e s p e c i a l i s t VBC t h a n t h a t i n t h e g e n e r a l i s t s FAW and C L , and a c t i v i t y t o w a r d t h e i s o t h i o c y a n a t e s i n t h e c r u c i f e r a d a p t e d c a b b a g e l o o p e r was 2 - t o 6 - f o l d h i g h e r t h a n t h a t i n t h e f a l l armyworm. The r e s u l t s s u p p o r t t h e n o t i o n t h a t g l u t a t h i o n e t r a n s f e r a s e s p l a y an i m p o r t a n t r o l e i n t h e f e e d i n g s t r a t e g i e s o f l e p i d o p t e r o u s i n s e c t s . The h i g h l y p o l y p h a g o u s i n s e c t s may h a v e e v o l v e d m u l t i p l e g l u t a t h i o n e transferases to d e t o x i f y the d i v e r s e t o x i c a l l e l o c h e m i c a l s e n c o u n t e r e d i n t h e i r h o s t p l a n t s . On t h e o t h e r h a n d , s p e c i a l i z e d i n s e c t s w h i c h f e e d on a n a r r o w r a n g e o f h o s t p l a n t s and e n c o u n t e r more s p e c i f i c a l l e l o c h e m i c a l s h a v e a s few as one form o f g l u t a t h i o n e t r a n s f e r a s e . T h e r e f o r e , the isozyme c o m p o s i t i o n o f glutathione transferase i n lepidopterous species i s r e l a t e d t o h o s t p l a n t f e e d i n g . More work i s n e e d e d t o l e a r n the s u b s t r a t e s p e c i f i c i t i e s of these isozymes b e f o r e one c a n f u l l y u n d e r s t a n d t h e m o l e c u l a r m e c h a n i s m s of glutathione-dependent d e t o x i c a t i o n i n these L e p i d o p t e r a . These r e s u l t s suggest t h a t g l u t a t h i o n e t r a n s f e r a s e s p l a y an i m p o r t a n t r o l e i n a l l e l o c h e m i c a l r e s i s t a n c e i n phytophagous L e p i d o p t e r a . Acknowledgments The o r i g i n a l r e s e a r c h r e p o r t e d h e r e was s u p p o r t e d i n p a r t by USDA ( C o m p e t i t i v e R e s e a r c h G r a n t s O f f i c e ) G r a n t s N o . 8 2 - C R C R - 1 - 1 0 9 1 and 8 5 - C R C R - 1 6 8 5 . I w o u l d l i k e t o t h a n k D r s . F . S l a n s k y and G . S . W h e e l e r f o r c r i t i c a l r e a d i n g o f t h i s manuscript. F l o r i d a A g r i c u l t u r a l Experiment S t a t i o n J o u r n a l S e r i e s No.R-01745. Literature Cited 1. 2. 3. 4. 5. 6. 7.
Chasseaud, L . F . Adv. Cancer Res. 1979, 29, 175- 274. D y k s t r a , W. G.; Dauterman, W. C. I n s e c t Biochem. 1978, 8, 263-265. B o y l a n d , E.; Chasseaud, L . F . Adv Enzymol. 1969, 32, 173-219. Motoyama, N ; Dauterman, W. C. Rev. Biochem. Toxicol. 1980, 2, 49-69. Oppenoorth, F . J.; van der Pas, L . J. T . ; Houx, N . W. H . Pestic. Biochem. P h y s i o l . 1979, 11, 176- 188. W a d l e i g h , R. W.; Y u , S. J. I n s e c t Biochem. 1987, 17, 759-764. W a d l e i g h , R. W.; Yu, S. J. J. Chem. E c o l . 1988, 14, 1279-1288. Mullin and Scott; Molecular Mechanisms of Insecticide Resistance ACS Symposium Series; American Chemical Society: Washington, DC, 1992.
190
MOLECULAR MECHANISMS OF INSECTICIDE RESISTANCE
8. 9. 10. 11. Downloaded by CALIFORNIA INST OF TECHNOLOGY on September 14, 2017 | http://pubs.acs.org Publication Date: September 22, 1992 | doi: 10.1021/bk-1992-0505.ch014
12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30.
Wadleigh, R. W.; Yu, S. J. J. Econ. Entomol. 1988, 81, 776-780. Clark, A. G. Comp, Biochem. P h y s i o l . 1989, 92B, 419-446. Clark, A. G . ; Letoa, M . ; Wong, S. T. L i f e S c i . 1977, 20, 141-148. Chang, C. K.; Clark, A. G . ; Fieldes, A.; Pound, S. Insect Biochem. 1981, 11, 179-186. Clark, A. G . ; Drake, B. Biochem. J. 1984, 217, 41-50. Cheng, E. Y.; L i n , D. F.; Chiu, C. S.; Kao, C. H. J. A a r i c . Res. China 1988, 37, 440-452. Balabaskaran, S.; Chuen, S. S.; Muniandy, S. Insect Biochem. 1989, 19, 435-443. Tiwar, N. K.; Singhal, S. S.; Sharma, R . ; Meagher, R. L.; Awasthi, Y. C. J. Econ. Entomol. 1991, 84, 1424-1432. Yu, S. J. P e s t i c . Biochem. P h y s i o l . 1989, 35, 97-105. Kulkarni, A. P.; Fabacher, D. L.; Hodgson, E. Gen. Pharmacol. 1980, 11, 437-441. Ottea, J. A.; Plapp, F. W., J r . P e s t i c . Biochem. P h y s i o l . . 1981, 15, 10-13. Hayaoka, T . ; Dauterman, W. C. P e s t i c . Biochem. P h y s i o l . 1982, 17, 113-119. Capua, S.; Cohen, E.; Gerson, U. Entomol. exp. appl. 1991, 59, 43-50. Yu, S. J. P e s t i c . Biochem. P h y s i o l . 1982, 18, 101-106. Yu, S. J. P e s t i c . Biochem. P h y s i o l . 1983, 19, 330-336. Dowd, P. F.; Rose, R. L.; Smith, C. M . ; Sparks, T. C. J. A a r i c . Food Chem. 1986, 34, 444-447. Lindroth, R. L . J. Chem. Ecol. 1989, 15, 20192029. Lindroth, R. L . Entomol. exp. appl. 1989, 50, 29-35. Yu, S. J. P e s t i c . Biochem. P h y s i o l . 1984, 22, 60-68. Lee, K. Insect Biochem. 1991, 21, 353-361. Brattsten, L . B.; Evans, C. K . ; Bonetti, S.; Zalkow, L . H. Comp. Biochem. P h y s i o l . 1984, 77C, 29-37. Rose, R. L.; Sparks, T. C . ; Smith, C. M. P e s t i c . Biochem. P h y s i o l . 1984, 34, 17-26. R i s k a l l a h , W.; Dauterman, W. C . ; Hodgson, E. Insect Biochem. 1986, 16, 491-499.
RECEIVED May 12, 1992
Mullin and Scott; Molecular Mechanisms of Insecticide Resistance ACS Symposium Series; American Chemical Society: Washington, DC, 1992.