Triazine herbicide resistance in the photosynthetic bacterium Rhodopseudomonas sphaeroides.
The photoaffinity herbicide azidoatrazine (2-azido-4-ethylamino-6-isopropylamino-s-triazine) selectively labels the L subunit of the reaction center of the photosynthetic bacterium Rhodopseudomonas sphaeroides. Herbicide-resistant mutants retain the L subunit and have altered binding properties for methylthio- and chloro-substituted triazines as well as altered equilibrium constants for electron transfer between primary and secondary electron acceptors. We suggest that a subtle alteration in the L subunit is responsible for herbicide resistance and that the L subunit is the functional analog of the 32-kDa Q(B) protein of chloroplast membranes.
Brown
A E
AE
Department of Botany and Microbiology, Auburn University, Auburn, AL 36849.
Gilbert
C W
CW
Guy
R
R
Arntzen
C J
CJ