Abstract
Effects of anoxia and subsequent reaeration on formation of hydrogen peroxide, and activities of catalase (EC 1.11.1.6) and guaiacol peroxidase (EC 1.11.1.7) were studied in wheat and rice plants that are contrasting in their tolerance to hypoxia. It was found that anoxia and reaeration, especially long-term, strongly increased the H2O2 production in hypoxia-intolerant wheat plants. Meanwhile, such treatment did not significantly entail peroxide production in rice, which is tolerant to oxygen lack. In these tolerant plants, the activities of catalase, as well as intra- and extracellular guaiacol peroxidases, rapidly increased under anoxia and the following oxidative stress. By contrast, wheat did not display stimulation of catalase activity; activation of its peroxidase occurred only in the shoots after a short anoxia and long reaeration. The increased or stable activities of catalase and peroxidase in the rice seedlings, under anoxia and reaeration, were inhibited by cycloheximide and, to smaller extent, actinomycin D. In rice, the stimulation of catalase activity was accompanied by the increased expression of the corresponding genes, in particular, OsCatB and OsCatС. The activities of apoplastic peroxidases were suppressed by brefeldin A. Electrophoresis did not reveal the emergence of new isoforms of guaiacol peroxidase under anoxia and post-anoxic aeration. Meanwhile, the activities of the majority of preexisting isoforms in rice and individual isoforms in wheat were considerably stimulated under these conditions. It is suggested that, in the tolerant plants subjected to anoxia and post-anoxic aeration, the activation of apoplastic peroxidases fulfills an adaptive function decomposing hydrogen peroxide in the cell wall and preventing its penetration into the cytosol. Under long-term reaeration, detoxification of ROS in the rice cytosol may be favored by activation of catalase and intracellular peroxidase. Unlike rice, the absence of activation of the antioxidant enzymes in the wheat cell wall allows ROS to penetrate inside the cell where they are deactivated by cytoplasmic forms of guaiacol peroxidase. The efficient work of antioxidant enzymes under anoxia, followed by post-anoxic aeration, prevents ROS accumulation in the tolerant plant and, thus, represents an important adaptation to both lack of oxygen and subsequent oxidative stress.
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Claims 18
Claim · model-written summary
Anoxia and reaeration strongly increased hydrogen peroxide production in wheat, especially after long exposure.
- Taxon
- wheat
Triticum aestivume0 - Treatment
- anoxia and reaeratione0
- Outcome
- H2O2 productione0
- Direction
- increasede0
- Qualifier
- especially long-terme0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“anoxia and reaeration, especially long-term, strongly increased the H2O2 production in hypoxia-intolerant wheat plants”
Claim · model-written summary
The treatment did not significantly increase peroxide production in rice.
- Taxon
- rice
Oryza sativae0 - Treatment
- such treatmente0
- Outcome
- peroxide productione0
- Direction
- did not significantly entaile0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“such treatment did not significantly entail peroxide production in rice”
Claim · model-written summary
Catalase activity rapidly increased in rice during anoxia and subsequent oxidative stress.
- Taxon
- riceOryza sativat0
- Treatment
- anoxia and the following oxidative stresse0
- Gene
- catalasee0
- Outcome
- activities of catalasee0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In these tolerant plants, the activities of catalase, as well as intra- and extracellular guaiacol peroxidases, rapidly increased under anoxia and the following oxidative stress.”
t0“Rice Plants”
Claim · model-written summary
Intra- and extracellular guaiacol peroxidase activity rapidly increased in rice under anoxia and subsequent oxidative stress.
- Taxon
- riceOryza sativat0
- Treatment
- anoxia and the following oxidative stresse0
- Gene
- guaiacol peroxidasese0
- Outcome
- intra- and extracellular guaiacol peroxidasese0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In these tolerant plants, the activities of catalase, as well as intra- and extracellular guaiacol peroxidases, rapidly increased under anoxia and the following oxidative stress.”
t0“Rice Plants”
Claim · model-written summary
Wheat catalase activity was not stimulated.
- Taxon
- wheatTriticum aestivume0
- Treatment
- Anoxia and Post-Anoxic Aerationt0
- Gene
- catalasee0
- Outcome
- catalase activitye0
- Direction
- did not display stimulatione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“wheat did not display stimulation of catalase activity”
t0“Anoxia and Post-Anoxic Aeration”
Claim · model-written summary
Wheat shoot peroxidase was activated only after short anoxia and long reaeration.
- Taxon
- WheatTriticum aestivumt0
- Organ / stage
- shootse0
- Treatment
- a short anoxia and long reaeratione0
- Gene
- peroxidasee0
- Outcome
- activation of its peroxidasee0
- Direction
- activatione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“activation of its peroxidase occurred only in the shoots after a short anoxia and long reaeration”
t0“Wheat”
Claim · model-written summary
Cycloheximide inhibited increased or stable catalase and peroxidase activities in rice seedlings.
- Taxon
- riceOryza sativae0
- Organ / stage
- seedlingse0
- Treatment
- cycloheximidee0
- Outcome
- activities of catalase and peroxidasee0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The increased or stable activities of catalase and peroxidase in the rice seedlings, under anoxia and reaeration, were inhibited by cycloheximide”
Claim · model-written summary
Actinomycin D inhibited increased or stable catalase and peroxidase activities in rice seedlings to a smaller extent.
- Taxon
- riceOryza sativae0
- Organ / stage
- seedlingse0
- Treatment
- actinomycin De0
- Outcome
- activities of catalase and peroxidasee0
- Direction
- inhibitede0
- Qualifier
- to smaller extente0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The increased or stable activities of catalase and peroxidase in the rice seedlings, under anoxia and reaeration, were inhibited by cycloheximide and, to smaller extent, actinomycin D.”
Claim · model-written summary
Rice catalase stimulation accompanied increased OsCatB expression.
- Taxon
- riceOryza sativae0
- Gene
- OsCatBe0
- Outcome
- increased expressione0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In rice, the stimulation of catalase activity was accompanied by the increased expression of the corresponding genes, in particular, OsCatB and OsCatС.”
Claim · model-written summary
Rice catalase stimulation accompanied increased OsCatС expression.
- Taxon
- riceOryza sativae0
- Gene
- OsCatСe0
- Outcome
- increased expressione0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In rice, the stimulation of catalase activity was accompanied by the increased expression of the corresponding genes, in particular, OsCatB and OsCatС.”
Claim · model-written summary
Brefeldin A suppressed apoplastic peroxidase activities.
- Taxon
- riceOryza sativat0
- Treatment
- brefeldin Ae0
- Outcome
- activities of apoplastic peroxidasese0
- Direction
- suppressede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The activities of apoplastic peroxidases were suppressed by brefeldin A.”
t0“Rice Plants”
Claim · model-written summary
Electrophoresis found no new guaiacol peroxidase isoforms after anoxia and post-anoxic aeration.
- Taxon
- Wheat and Rice PlantsOryza sativaTriticum aestivumt0
- Gene
- guaiacol peroxidasee0
- Outcome
- did not reveal the emergence of new isoforms of guaiacol peroxidasee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Electrophoresis did not reveal the emergence of new isoforms of guaiacol peroxidase under anoxia and post-anoxic aeration.”
t0“Wheat and Rice Plants”
Claim · model-written summary
Most existing rice peroxidase isoforms were stimulated under these conditions.
- Taxon
- riceOryza sativae0
- Treatment
- Anoxia and Post-Anoxic Aerationt0
- Outcome
- activities of the majority of preexisting isoformse0
- Direction
- stimulatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the activities of the majority of preexisting isoforms in rice and individual isoforms in wheat were considerably stimulated under these conditions.”
t0“Anoxia and Post-Anoxic Aeration”
Claim · model-written summary
Individual existing wheat peroxidase isoforms were stimulated under these conditions.
- Taxon
- wheatTriticum aestivume0
- Treatment
- Anoxia and Post-Anoxic Aerationt0
- Outcome
- individual isoformse0
- Direction
- stimulatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the activities of the majority of preexisting isoforms in rice and individual isoforms in wheat were considerably stimulated under these conditions.”
t0“Anoxia and Post-Anoxic Aeration”
Claim · model-written summary
Apoplastic peroxidase activation is suggested to decompose cell-wall peroxide and prevent its entry into the cytosol in tolerant plants.
- Taxon
- riceOryza sativat0
- Outcome
- preventing its penetration into the cytosole0
- Qualifier
- activation of apoplastic peroxidasese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in the tolerant plants subjected to anoxia and post-anoxic aeration, the activation of apoplastic peroxidases fulfills an adaptive function decomposing hydrogen peroxide in the cell wall and preventing its penetration into the cytosol”
t0“Rice Plants”
Claim · model-written summary
Catalase and intracellular peroxidase activation may aid rice cytosolic ROS detoxification during long reaeration.
- Taxon
- riceOryza sativae0
- Outcome
- detoxification of ROS in the rice cytosole0
- Qualifier
- activation of catalase and intracellular peroxidasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under long-term reaeration, detoxification of ROS in the rice cytosol may be favored by activation of catalase and intracellular peroxidase.”
Claim · model-written summary
The authors propose that missing antioxidant activation in wheat cell walls permits ROS entry and cytoplasmic peroxidase deactivation.
- Taxon
- wheatTriticum aestivume0
- Outcome
- ROS to penetrate inside the celle0
- Qualifier
- absence of activation of the antioxidant enzymes in the wheat cell walle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the absence of activation of the antioxidant enzymes in the wheat cell wall allows ROS to penetrate inside the cell where they are deactivated by cytoplasmic forms of guaiacol peroxidase.”
Claim · model-written summary
Antioxidant enzyme action is proposed to prevent ROS accumulation in tolerant plants.
- Taxon
- riceOryza sativat0
- Outcome
- prevents ROS accumulatione0
- Qualifier
- efficient work of antioxidant enzymese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The efficient work of antioxidant enzymes under anoxia, followed by post-anoxic aeration, prevents ROS accumulation in the tolerant plant”
t0“Rice Plants”
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See all 10 papers →oxidative · physiology: antioxidant enzymes · Oryza sativa (rice)Results agree
1 paper in the same direction as this paper
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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.