Pesticide Metabolism in Plants
FENSULFOTHION
TETRACHLORVINPHOS
FLUORODIFEN
- - -..... - R-SCH 3
CH3~1
--~.- HO-tH~CI
CI
C'hC'
C I ¥ C I
CI
---. . . . . .
-)0:::
CI
PCNB
&' -----i._ 6~' -----0_- CONJUGATES
CIVN0 2
CIVNH2
01 NOBEN
CHLORAMBEN
37
Figure 2.12. Reductive metabolism of fensulfothion, tetrachlorvinphos, ftuorodifen, PeNS, and
dinoben in plants.
2.3.3. Hydrolysis
Hydrolysis of esters, amides, and nitriles is a common reaction in plants.
Hydrolysis appears to be a selective mechanism for some pesticides in plants.
The herbicide propanil was hydrolyzed by a particular enzyme, aryl acylamidase, from resistant rice (Fig. 2. 13) (Frear and Still, 1968; Still and Kuzerian,
1967). This enzyme was associated with the chloroplast membrane from rice
(Still and Kuzerian, 1967). The level of enzyme activity in resistant rice leaves
was 60 times higher than in the leaves of susceptile barnyard grass. However,
FENSULFOTHION
TETRACHLORVINPHOS
FLUORODIFEN
- - -..... - R-SCH 3
CH3~1
--~.- HO-tH~CI
CI
C'hC'
C I ¥ C I
CI
---. . . . . .
-)0:::
CI
PCNB
&' -----i._ 6~' -----0_- CONJUGATES
CIVN0 2
CIVNH2
01 NOBEN
CHLORAMBEN
37
Figure 2.12. Reductive metabolism of fensulfothion, tetrachlorvinphos, ftuorodifen, PeNS, and
dinoben in plants.
2.3.3. Hydrolysis
Hydrolysis of esters, amides, and nitriles is a common reaction in plants.
Hydrolysis appears to be a selective mechanism for some pesticides in plants.
The herbicide propanil was hydrolyzed by a particular enzyme, aryl acylamidase, from resistant rice (Fig. 2. 13) (Frear and Still, 1968; Still and Kuzerian,
1967). This enzyme was associated with the chloroplast membrane from rice
(Still and Kuzerian, 1967). The level of enzyme activity in resistant rice leaves
was 60 times higher than in the leaves of susceptile barnyard grass. However,