Low resistance against novel 2-benzylamino-1,3,5-triazine herbicides in atrazine-resistant Chenopodium album plants.
The effects of nine novel 2-benzylamino-1,3,5-triazines on photosynthetic reactions were measured in thylakoids isolated from wild-type and atrazine-resistant plants of Chenopodium album. The resistant plants have a mutation of serine for glycine at position 264 of the D1 protein. The measurement of oxygen evolution and chlorophyll a fluorescence induction indicated a 2-4-fold stronger inhibition by the 6-trifluoromethyl analogues of Photosystem II-dependent electron flow than atrazine. Analogues having a 6-methyl-, 6-monofluoromethyl or 6-difluoromethyl substitution were weak inhibitors, indicating that the 6-trifluoro group is very important for strong inhibition. All the nine novel 2-benzylamino-1,3,5-triazines were almost as active in wild-type as in atrazine-resistant thylakoids, indicating that the benzylamino substitution may be important for the lack of resistance in the atrazine-resistant plants.
Kohno
H
H
Graduate School of Agricultural Science, Tamagawa University, Tamagawa Gakuen, Machida-shi, Tokyo, 194-8610, Japan.
Ohki
A
A
Ohki
S
S
Koizumi
K
K
Van den Noort
M E
ME
Rodrigues
G C
GC
Van Rensen
J J
JJ
Wakabayashi
K
K