Cytochrome herbicides

Cytochrome P-450 is frequently the oxygenase which detoxifies xenobiotics, including herbicides. Blocking the metaboHsm of a herbicide increases the activity or delays the inactivation, thus increasing the effectiveness of such herbicides as chlortoluron [15545-48-9] and bentazon [25057-89-0]... 

O Keefe DP, JA Romesser, KJ Leto (1988) Identification of constitutive and herbicide inducible cytochromes P-450 in Streptomyces griseolus. Arch Microbiol 149 406-412. 

Nagy I, F Compernolle, K Ghys, J Vanderleyden, R De Mot (1995a) A single cytochrome P-450 system is involved in degradation of the herbicides EPTC (S-ethyl dipropylthiocarbamate) and atrazine by Rhodococcus sp. N186/21. Appl Environ Microbiol 61 2056-2060. 

Nagy 1, G Schools, F Compermolle, P Proost, J Vanderleyden, R De Mot (1995b) Degradation of the thiocar-bamate herbicide EPTC S-ethyl dipropylcarbamoylthioate and biosafening by Rhodococcus sp. strain N186/21 involve an inducible cytochrome P-450 system and aldehyde dehydrogenase. J Bacterial 177 676-687. 

Sulfonylureas are the basis of a large group of herbicides. Cytochrome P450 enzymes in Streptomyces griseolus transform the sulfonylureas by hydroxylation (Omer et al. 1990) leaving the -SO2NHCONH- part of the structure unaltered (Harder et al. 1991). 

Harder PA, DP O Keefe, JA Romesser, KJ Leto, CA Omer (1991) Isolation and characterization of Strepto-myces griseolus deletion mutants affected in cytochrome P-450-mediated herbicide metabolism. Mol Gen Genet 227 238-244. 

Omer CA, R Lenstra, PJ Little, C Dean, JM Tepperman, KJ Leto, JA Romesser, DP O Keefe (1990) Genes for two herbicide-inducible cytochromes P-450 from Streptomyces griseolus. J Bacterial 172 3335-3345. 

WERCK-REICHHART, D., HEHN, A., DIDIERJEAN, L Cytochromes P450 for engineering herbicide tolerance, Trends Plant. Sci., 2000,3, 116-123. 

StrauberH, Muller RH, Babel W (2003) Evidence of cytochrome P450-catalyzed cleavage of the ether bond of phenoxybutyrate herbicides in Rhodococcus erythropolis K2-3. Biodegradation 14 41-50... 

Siminszky B (2006) Plant cytochrome P450-mediated herbicide metabolism. Phytochem Rev 5 445 158... 

Cytochromes P450 Increased for TCE, herbicides Increased for TCE, herbicides... 

Eventually, the electrons in PQBH2 pass through the cytochrome b6f complex (Fig. 19-49). The electron initially removed from P680 is replaced with an electron obtained from the oxidation of water, as described below. The binding site for plastoquinone is the point of action of many commercial herbicides that kill plants by blocking electron transfer through the cytochrome b6f complex and preventing photosynthetic ATP production. 

Didierjean, L., Gondet, L., Perkins, R., Lau, S.-M.C., Schaller, H., O Keefe D.P., and Werck-Reichhart, D., Engineering herbicide metabolism in tobacco and Arabidopsis with CYP76B1, a cytochrome P450 enzyme from Jerusalem artichoke, Plant Physiol., 130, 179-189, 2002. 

Batard, Y., Robineau, T., Durst, F., Werck-Reichart, D., and Didierjean, L., Use of Helianthus tuberosus Cytochrome P450 Protein CYP76B1 for Improved Resistance to Phenylurea Herbicides and Pesticides in Transgenic Plants and for Soil and groundwater bioremediation, U.S. Patent 6376753, 2002. 

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