Abstract
The effects of the dichloroacetamide safener benoxacor on maize (Zea mays L. var Pioneer 3906) growth and glutathione S-transferase (GST) activity were evaluated, and GST isozymes induced by benoxacor were partially separated, characterized, and identified. Protection from metolachlor injury was closely correlated with GST activity, which was assayed with metolachlor as a substrate, as benoxacor concentration increased from 0.01 to 1 [mu]M. GST activity continued to increase at higher benoxacor concentrations (10 and 100 [mu]M), but no further protection was observed. Total GST activity with metolachlor as a substrate increased 2.6- to 3.8-fold in response to 1 [mu]M benoxacor treatment. Total GST activity from maize treated with or without 1 [mu]M benoxacor was resolved by fast protein liquid chromatography anion-exchange chromatography into four major activities, designated activity peaks A, B, C, and D in their order of elution. These GST activity peaks were enhanced to varying degrees by benoxacor. Activity peak B showed the least induction, whereas activity peak A was absent constitutively and thus highly induced by benoxacor. In contrast to earlier reports, there appear to be not one, but at least two, major constitutive isozymes (activity peaks A and D) having activity with metolachlor as substrate; there were at least three such isozymes in benoxacor-treated maize (activity peaks A, C, and D). The elution volumes of activity peaks A, B, C, and D were compared with those of partially purified maize GST I and GST II; also, the reactivity of polypeptides in these activity peaks with antisera to GST I or GST I/III (mixture) was evaluated. Evidence from these experiments indicated that activity peak B contained GST I, and activity peak C contained GST II and GST III. Activity peaks A and D contained unique GSTs that may play a major role in metolachlor metabolism and in the safening activity of benoxacor in maize. Isozymes present in activity peaks A and D were not detected in earlier reports because of the very low activity with the artificial substrate 1-chloro-2,4-dinitrobenzene. Immunoblotting experiments also indicated the presence of numerous unidentified GST subunits, including multiple subunits in chromatography fractions containing single peaks of GST activity; this is indicative of the likely complexity and diversity of the maize GST enzyme family.
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Claims 15
Claim · model-written summary
Metolachlor protection tracked GST activity as benoxacor rose from 0.01 to 1 [mu]M.
Zea maysNot reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Protection from metolachlor injury was closely correlated with GST activity, which was assayed with metolachlor as a substrate, as benoxacor concentration increased from 0.01 to 1 [mu]M.”
t0“Maize”
Claim · model-written summary
GST activity rose at higher benoxacor concentrations without further protection.
- Treatment
- benoxacor concentrations (10 and 100 [mu]M)e0
- Gene
- GSTe0
- Outcome
- GST activitye0
- Direction
- increaseinferrede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GST activity continued to increase at higher benoxacor concentrations (10 and 100 [mu]M), but no further protection was observed.”
t0“Maize”
Claim · model-written summary
Further metolachlor protection was absent at 10 and 100 [mu]M benoxacor.
- Treatment
- benoxacor concentrations (10 and 100 [mu]M)e0
- Outcome
- no further protectione0
- Direction
- no furthere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GST activity continued to increase at higher benoxacor concentrations (10 and 100 [mu]M), but no further protection was observed.”
t0“Maize”
Claim · model-written summary
One micromolar benoxacor increased GST activity with metolachlor substrate 2.6- to 3.8-fold.
- Treatment
- 1 [mu]M benoxacor treatmente0
- Gene
- GSTe0
- Outcome
- Total GST activity with metolachlor as a substratee0
- Direction
- increasede0
- Value
- 2.6- to 3.8-folde0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Total GST activity with metolachlor as a substrate increased 2.6- to 3.8-fold in response to 1 [mu]M benoxacor treatment.”
t0“Maize”
Claim · model-written summary
Chromatography resolved four major GST activities.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Total GST activity from maize treated with or without 1 [mu]M benoxacor was resolved by fast protein liquid chromatography anion-exchange chromatography into four major activities, designated activity peaks A, B, C, and D in their order of elution.”
Claim · model-written summary
Benoxacor enhanced the four GST activity peaks to varying degrees.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“These GST activity peaks were enhanced to varying degrees by benoxacor.”
t0“Maize”
Claim · model-written summary
Activity peak B showed the least induction.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Activity peak B showed the least induction, whereas activity peak A was absent constitutively and thus highly induced by benoxacor.”
t0“Maize”
Claim · model-written summary
Activity peak A was absent constitutively and highly induced by benoxacor.
- Treatment
- benoxacore0
- Gene
- activity peak Ae0
- Outcome
- activity peak Ae0
- Direction
- highly inducede0
- Comparator
- constitutivelye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Activity peak B showed the least induction, whereas activity peak A was absent constitutively and thus highly induced by benoxacor.”
t0“Maize”
Claim · model-written summary
At least two major constitutive GST isozymes with metolachlor activity were reported.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“there appear to be not one, but at least two, major constitutive isozymes (activity peaks A and D) having activity with metolachlor as substrate”
t0“Maize”
Claim · model-written summary
At least three metolachlor-active isozymes were reported in benoxacor-treated maize.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“there were at least three such isozymes in benoxacor-treated maize (activity peaks A, C, and D).”
Claim · model-written summary
Activity peak B contained GST I.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“activity peak B contained GST I, and activity peak C contained GST II and GST III.”
t0“Maize”
Claim · model-written summary
Activity peak C contained GST II and GST III.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“activity peak B contained GST I, and activity peak C contained GST II and GST III.”
t0“Maize”
Claim · model-written summary
Activity peaks A and D contained unique GSTs potentially involved in metolachlor metabolism and safening.
- Gene
- unique GSTse0
- Outcome
- metolachlor metabolism and in the safening activity of benoxacore0
- Qualifier
- may play a major rolee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Activity peaks A and D contained unique GSTs that may play a major role in metolachlor metabolism and in the safening activity of benoxacor in maize.”
Claim · model-written summary
Very low activity with 1-chloro-2,4-dinitrobenzene explains the earlier nondetection of peaks A and D.
- Gene
- Isozymes present in activity peaks A and De0
- Outcome
- were not detected in earlier reportse0
- Qualifier
- very low activity with the artificial substrate 1-chloro-2,4-dinitrobenzenee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Isozymes present in activity peaks A and D were not detected in earlier reports because of the very low activity with the artificial substrate 1-chloro-2,4-dinitrobenzene.”
t0“Maize”
Claim · model-written summary
Immunoblots showed numerous unidentified GST subunits, including multiple subunits in fractions with single activity peaks.
- Gene
- GST subunitse0
- Outcome
- numerous unidentified GST subunits, including multiple subunits in chromatography fractions containing single peaks of GST activitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Immunoblotting experiments also indicated the presence of numerous unidentified GST subunits, including multiple subunits in chromatography fractions containing single peaks of GST activity”
t0“Maize”
The same questions in other papers
Benoxacor · molecular: metabolites · Zea mays (maize)Positive and negative results
3 papers in the same direction as this paper · 1 in the opposite direction
- positive
- negative
- positive
1 paper more in this group
See all 5 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.