Chloroplast membrane alterations in triazine-resistant Amaranthus retroflexus biotypes
- 1 January 1979
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 76 (1), 278-282
- https://doi.org/10.1073/pnas.76.1.278
Abstract
The effectiveness of diuron, atrazine, procyazine and cyanazine were compared in controlling growth of redroot pigweed (A. retroflexus L.) in hydroponic culture. A very marked differential inhibition response was observed for atrazine between resistant and susceptible biotypes. Procyazine and cyanazine exhibited less dramatic differential responses, whereas diuron was equally effective in controlling growth in both biotypes. Photosystem II activity of chloroplasts from both triazine-resistant and triazine-susceptible biotypes was inhibited by diuron but only the chloroplasts from triazine-susceptible biotypes were inhibited significantly by atrazine. The photochemical activity of chloroplasts from triazine-resistant biotypes was partially resistant to procyazine or cyanazine inhibition. The parallel lack of diuron differential effects, partial procyazine and cyanazine differential response, and very marked atrazine differential response in both whole plant and chloroplast assays indicates that the chloroplast is the site of selective herbicide tolerance in these triazine-resistant redroot pigweed biotypes. Photosystem II photochemical properties were characterized by analysis of chlorophyll fluorescence transients in the presence or absence of herbicides. Data with susceptible chloroplasts indicated that both diuron and atrazine inhibit electron flow very near the primary electron acceptor of photosystem II. Only diuron altered the fluorescence transient in resistant chloroplasts. In untreated preparations there were marked differences in the fast phases of the fluorescence increase in resistant vs. susceptible chloroplasts; these data are interpreted as showing that the resistant plastids have an alteration in the rate of reoxidation of the primary photosystem II electron acceptor. Electrophoretic analysis of chloroplast membrane proteins of the 2 biotypes showed small changes in the electrophoretic mobilities of 2 polypeptide species. The data provide evidence for the following herbicide resistance mechanism: genetically controlled modification of the herbicide target site.This publication has 10 references indexed in Scilit:
- Involvement of the light-harvesting complex in cation regulation of excitation energy distribution in chloroplastsArchives of Biochemistry and Biophysics, 1978
- STUDIES ON THE DIFFERENTIAL TOLERANCE OF TWO LAMB’S-QUARTERS SELECTIONS TO TRIAZINE HERBICIDESCanadian Journal of Plant Science, 1977
- Relationship between inhibitor binding by chloroplasts and inhibition of photosynthetic electron transportBiochimica et Biophysica Acta (BBA) - Bioenergetics, 1977
- Mechanism of Atrazine Resistance in Lambsquarters and PigweedWeed Science, 1977
- Studies on the structural and functional organization of system II of photosynthesis. The use of trypsin as a structurally selective inhibitor at the outer surface of the thylakoid membraneBiochimica et Biophysica Acta (BBA) - Bioenergetics, 1976
- Studies on the Mechanism ofs-Triazine Resistance in Common GroundselWeed Science, 1976
- Further Chemical and Morphological Characterization of Chloroplast Membranes from a Chlorophyll b-less Mutant of Hordeum vulgarePlant Physiology, 1975
- [19] Estimation of pool sizes and kinetic constantsMethods in Enzymology, 1972
- Electrophoretic analysis of the major polypeptides of the human erythrocyte membraneBiochemistry, 1971
- Sites of Synthesis of Chloroplast Membrane Polypeptides in Chlamydomonas reinhardi y-1Journal of Biological Chemistry, 1970