Enhanced Catalytic Constant for GlutathioneS-Transferase (Atrazine) Activity in an Atrazine-ResistantAbutilon theophrastiBiotype

Plaisance, Kathryn L.; Gronwald, John W.

doi:10.1006/pest.1998.2387

Cited by 28 publications

(7 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These results support the correlation of specific GST catalytic activity towards xenobiotics, rather than increased overall GST activity, with herbicide tolerance (Deng and Hatzios, 2002;Plaisance and Gronwald, 1999). Furthermore the increased GPOX activity of GmGSTU4 seems to have no significant contribution to chloroacetanilide herbicides tolerance, at least under the in vitro conditions that were used, possibly due to the fact that these herbicides act primarily by inhibiting metabolic processes such as very long chain fatty acid synthesis (Boger et al, 2000), which does not mainly involve generation of oxidative stress.…”

Section: Plant Linessupporting

confidence: 62%

Overexpression of a specific soybean GmGSTU4 isoenzyme improves diphenyl ether and chloroacetanilide herbicide tolerance of transgenic tobacco plants

Benekos¹,

Kissoudis²,

Nianiou-Obeidat³

et al. 2010

Journal of Biotechnology

View full text Add to dashboard Cite

Section: Plant Linessupporting

confidence: 62%

Overexpression of a specific soybean GmGSTU4 isoenzyme improves diphenyl ether and chloroacetanilide herbicide tolerance of transgenic tobacco plants

Benekos¹,

Kissoudis²,

Nianiou-Obeidat³

et al. 2010

Journal of Biotechnology

View full text Add to dashboard Cite

“…For example, Plaisance and Gronwald (1999) reported that glutathione S-transferases (plant cell proteins believed to play an important role in protecting plants from various environmental stresses such as plant diseases and pesticides) attach lipid hydroperoxides, which are harmful compounds that are generated in plants exposed to various stresses such as drought and pathogen invasion. Two glutathione S-transferase proteins have been purified from sorghum that have the ability to detoxify lipid hydroperoxides (Plaisance and Gronwald 1999). These proteins might play an important role in protecting plants from toxic lipid hydroperoxides that are formed under drought stress conditions.…”

Section: Differently Expressed Genes Co-segregating With Drought Relamentioning

confidence: 99%

Identification of drought-inducible genes and differentially expressed sequence tags in barley

et al. 2004

View full text Add to dashboard Cite

Drought limits cereal yields in several regions of the world and plant water status plays an important role in tolerance to drought. To investigate and understand the genetic and physiological basis of drought tolerance in barley, differentially expressed sequence tags (dESTs) and candidate genes for the drought response were mapped in a population of 167 F8 recombinant inbred lines derived from a cross between "Tadmor" (drought tolerant) and "Er/Apm" (adapted only to specific dry environments). One hundred sequenced probes from two cDNA libraries previously constructed from drought-stressed barley (Hordeum vulgare L., var. Tokak) plants and 12 candidate genes were surveyed for polymorphism, and 33 loci were added to a previously published map. Composite interval mapping was used to identify quantitative trait loci (QTL) associated with drought tolerance including leaf relative water content, leaf osmotic potential, osmotic potential at full turgor, water-soluble carbohydrate concentration, osmotic adjustment, and carbon isotope discrimination. A total of 68 QTLs with a limit of detection score > or =2.5 were detected for the traits evaluated under two water treatments and the two traits calculated from both treatments. The number of QTLs identified for each trait varied from one to 12, indicating that the genome contains multiple genes affecting different traits. Two candidate genes and ten differentially expressed sequences were associated with QTLs for drought tolerance traits.

show abstract

“…A notable exception is a biotype of the dicot weed Abutilon theophrasti, which developed resistance to the herbicide atrazine because of increased activity of a specific GST isoenzyme. However, the elevated activity was because of a mutation that increased the catalytic constant of the enzyme toward atrazine, rather than an increase in the abundance of this protein (Plaisance and Gronwald, 1999). The importance of GSTs in herbicide tolerance has been clearly demonstrated in transgenic tobacco (Nicotiana tabacum) plants expressing a maize (Zea mays) GST active in conjugating chloroacetanilide herbicides, such as metolachlor (Jepson et al, 1997).…”

mentioning

confidence: 99%

Induction of Glutathione S-Transferases in Arabidopsis by Herbicide Safeners

et al. 2002

View full text Add to dashboard Cite

Herbicide safeners increase herbicide tolerance in cereals but not in dicotyledenous crops. The reason(s) for this difference in safening is unknown. However, safener-induced protection in cereals is associated with increased expression of herbicide detoxifying enzymes, including glutathione S-transferases (GSTs). Treatment of Arabidopsis seedlings growing in liquid medium with various safeners similarly resulted in enhanced GST activities toward a range of xenobiotics with benoxacor, fenclorim, and fluxofenim being the most effective. Safeners also increased the tripeptide glutathione content of Arabidopsis seedlings. However, treatment of Arabidopsis plants with safeners had no effect on the tolerance of seedlings to chloroacetanilide herbicides. Each safener produced a distinct profile of enhanced GST activity toward different substrates suggesting a differential induction of distinct isoenzymes. This was confirmed by analysis of affinity-purified GST subunits by two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. AtGSTU19, a tau class GST, was identified as a dominant polypeptide in all samples. When AtGSTU19 was expressed in Escherichia coli, the recombinant enzyme was highly active toward 1-chloro-2,4-dinitrobenzene, as well as chloroacetanilide herbicides. Immunoblot analysis confirmed that AtGSTU19 was induced in response to several safeners. Differential induction of tau GSTs, as well as members of the phi and theta classes by safeners, was demonstrated by RNA-blot analysis. These results indicate that, although Arabidopsis may not be protected from herbicide injury by safeners, at least one component of their detoxification systems is responsive to these compounds.Plants actively detoxify both endogenous toxins, such as secondary metabolites and degradation products arising from oxidative stress, and exogenous man-made chemicals, such as herbicides, using a three-phase detoxification system (Neuefeind et al., 1997). In the first phase, oxidation, reduction, or hydrolysis reactions catalyzed by enzymes such as cytochrome P450 monooxygenases result in the exposure, or introduction, of a functional group. Phase two enzymes then catalyze the conjugation of these metabolites with sugars or the tripeptide glutathione (GSH). In the case of GSH, glutathione S-transferases (GSTs) catalyze this conjugation reaction. In the third phase of metabolism, molecules "tagged" with GSH are recognized by ATP-binding cassette transporters in the tonoplast or plasma membrane, which then transfer these conjugates into the vacuole or apoplast (Rea, 1999).GSTs constitute a family of multifunctional enzymes present in both plants and animals. These dimeric enzymes catalyze the conjugation of GSH to a variety of electrophilic, hydrophobic, and often toxic substrates, thereby reducing their toxicity (Marrs, 1996;Dixon et al., 1998). In addition to GSH conjugation, GSTs may also exhibit glutathione peroxidase (GPOX) or isomerase activities, or function as binding proteins known as ligandins (Edwards et al., ...

show abstract

Enhanced Catalytic Constant for GlutathioneS-Transferase (Atrazine) Activity in an Atrazine-ResistantAbutilon theophrastiBiotype

Cited by 28 publications

References 58 publications

Overexpression of a specific soybean GmGSTU4 isoenzyme improves diphenyl ether and chloroacetanilide herbicide tolerance of transgenic tobacco plants

Overexpression of a specific soybean GmGSTU4 isoenzyme improves diphenyl ether and chloroacetanilide herbicide tolerance of transgenic tobacco plants

Identification of drought-inducible genes and differentially expressed sequence tags in barley

Induction of Glutathione S-Transferases in Arabidopsis by Herbicide Safeners

Contact Info

Product

Resources

About