Abstract
The most important part of the plant antioxidant system is the ascorbate-glutathione cycle (AGC), the activity of which is observed upon exposure to a range of stressors, including lack of O2, and oxidative stress occurring immediately after the restoration of oxygen access, hereafter termed reaeration or post-anoxia. The operation of the AGC (enzymes and low-molecular components) in wheat (Triticum aestivum, cv. Leningradka, non-resistant to hypoxia) and rice (Oryza sativa, cv. Liman, resistant) seedlings after 24 h anoxia and 1 h or 24 h reaeration was studied. Significant accumulation of oxidized forms of ascorbate and glutathione was revealed in the non-resistant plant (wheat) after 24 h of anoxia and reaeration, indicating the development of oxidative stress. In the resistant plant (rice), reduced forms of these antioxidants prevailed both in normoxia and under stress, which may indicate their intensive reduction. In wheat, the activities of ascorbate peroxidase and dehydroascorbate reductase in shoots, and monodehydroascorbate reductase and glutathione reductase in roots decreased under anoxia and reaeration. The activity of antioxidant enzymes was maintained in rice under lack of oxygen (ascorbate peroxidase, glutathione reductase) and increased during post-anoxia (AGC reductases). Anoxia stimulated accumulation of mRNA of the organellar ascorbate peroxidase genes OsAPX3, OsAPX5 in shoots, and OsAPX3-5 and OsAPX7 in roots. At post-anoxia, the contribution of the OsAPX1 and OsAPX2 genes encoding the cytosolic forms of the enzyme increased in the whole plant, and so did that of the OsAPX8 gene for the plastid form of the enzyme. The accumulation of mRNA of the genes OsMDAR2 and OsMDAR4 encoding peroxisomal and cytosolic monodehydroascorbate reductase as well as the OsGR2 and OsGR3 for cytosolic and organellar glutathione reductase was activated during reaeration in shoots and roots. In most cases, O2 deficiency activated the genes encoding the peroxisomal, plastid, and mitochondrial forms of the enzymes, and upon reaeration, an enhanced activity of the genes encoding the cytoplasmic forms was observed. Taken together, the inactivation of AGC enzymes was revealed in wheat seedlings during anoxia and subsequent reaeration, which disrupted the effective operation of the cycle and triggered the accumulation of oxidized forms of ascorbate and glutathione. In rice, anoxia led to the maintenance of the activity of AGC enzymes, and reaeration stimulated it, including at the level of gene expression, which ensured the effective operation of AGC.
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Claims 18
Claim · model-written summary
In wheat seedlings, oxidized forms of ascorbate and glutathione accumulated after 24 h of anoxia and reaeration, indicating oxidative stress.
- Taxon
- wheat
Triticum aestivumt0 - Material
- Leningradkae0
- Treatment
- after 24 h of anoxia and reaeratione1
- Outcome
- accumulation of oxidized forms of ascorbate and glutathionee1
- Direction
- accumulatione1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Ascorbate-glutathione cycle in wheat and rice seedlings under anoxia and subsequent reaeration”
e0“The operation of the AGC (enzymes and low-molecular components) in wheat (Triticum aestivum, cv. Leningradka, non-resistant to hypoxia) and rice (Oryza sativa, cv. Liman, resistant) seedlings after 24 h anoxia and 1 h or 24 h reaeration was studied”
e1“Significant accumulation of oxidized forms of ascorbate and glutathione was revealed in the non-resistant plant (wheat) after 24 h of anoxia and reaeration, indicating the development of oxidative stress”
Claim · model-written summary
In rice seedlings, reduced forms of ascorbate and glutathione prevailed in normoxia and under stress.
- Taxon
- rice
Oryza sativat0 - Treatment
- under stresse2
- Outcome
- reduced forms of these antioxidantse2
- Direction
- prevailede2
- Comparator
- normoxiae2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Ascorbate-glutathione cycle in wheat and rice seedlings under anoxia and subsequent reaeration”
e2“In the resistant plant (rice), reduced forms of these antioxidants prevailed both in normoxia and under stress, which may indicate their intensive reduction”
Claim · model-written summary
In wheat shoots, ascorbate peroxidase and dehydroascorbate reductase activities decreased under anoxia and reaeration.
- Taxon
- wheatTriticum aestivume3
- Organ / stage
- shootse3
- Treatment
- anoxia and reaeratione3
- Gene
- ascorbate peroxidase and dehydroascorbate reductasee3
- Outcome
- activitiese3
- Direction
- decreasede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“In wheat, the activities of ascorbate peroxidase and dehydroascorbate reductase in shoots, and monodehydroascorbate reductase and glutathione reductase in roots decreased under anoxia and reaeration”
Claim · model-written summary
In wheat roots, monodehydroascorbate reductase and glutathione reductase activities decreased under anoxia and reaeration.
- Taxon
- wheatTriticum aestivume3
- Organ / stage
- rootse3
- Treatment
- anoxia and reaeratione3
- Gene
- monodehydroascorbate reductase and glutathione reductasee3
- Outcome
- activitiese3
- Direction
- decreasede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“In wheat, the activities of ascorbate peroxidase and dehydroascorbate reductase in shoots, and monodehydroascorbate reductase and glutathione reductase in roots decreased under anoxia and reaeration”
Claim · model-written summary
In rice under lack of oxygen, ascorbate peroxidase and glutathione reductase activities were maintained.
- Taxon
- riceOryza sativae4
- Treatment
- lack of oxygene4
- Gene
- ascorbate peroxidase, glutathione reductasee4
- Outcome
- activity of antioxidant enzymese4
- Direction
- maintainede4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“The activity of antioxidant enzymes was maintained in rice under lack of oxygen (ascorbate peroxidase, glutathione reductase) and increased during post-anoxia (AGC reductases)”
Claim · model-written summary
In rice, AGC reductase activity increased during post-anoxia.
- Taxon
- riceOryza sativae4
- Treatment
- post-anoxiae4
- Outcome
- AGC reductasese4
- Direction
- increasede4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“The activity of antioxidant enzymes was maintained in rice under lack of oxygen (ascorbate peroxidase, glutathione reductase) and increased during post-anoxia (AGC reductases)”
Claim · model-written summary
Anoxia stimulated accumulation of OsAPX3 and OsAPX5 mRNA in rice shoots.
- Taxon
- riceOryza sativat0
- Organ / stage
- shootse5
- Treatment
- Anoxiae5
- Gene
- OsAPX3, OsAPX5e5
- Outcome
- accumulation of mRNAe5
- Direction
- stimulatede5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Ascorbate-glutathione cycle in wheat and rice seedlings under anoxia and subsequent reaeration”
e5“Anoxia stimulated accumulation of mRNA of the organellar ascorbate peroxidase genes OsAPX3, OsAPX5 in shoots, and OsAPX3-5 and OsAPX7 in roots”
Claim · model-written summary
Anoxia stimulated accumulation of OsAPX3-5 and OsAPX7 mRNA in rice roots.
- Taxon
- riceOryza sativat0
- Organ / stage
- rootse5
- Treatment
- Anoxiae5
- Gene
- OsAPX3-5 and OsAPX7e5
- Outcome
- accumulation of mRNAe5
- Direction
- stimulatede5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Ascorbate-glutathione cycle in wheat and rice seedlings under anoxia and subsequent reaeration”
e5“Anoxia stimulated accumulation of mRNA of the organellar ascorbate peroxidase genes OsAPX3, OsAPX5 in shoots, and OsAPX3-5 and OsAPX7 in roots”
Claim · model-written summary
After post-anoxia, the contribution of cytosolic OsAPX1 and OsAPX2 increased in the whole rice plant.
- Taxon
- riceOryza sativat0
- Organ / stage
- whole plante6
- Treatment
- post-anoxiae6
- Gene
- OsAPX1 and OsAPX2e6
- Outcome
- contributione6
- Direction
- increasede6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Ascorbate-glutathione cycle in wheat and rice seedlings under anoxia and subsequent reaeration”
e6“At post-anoxia, the contribution of the OsAPX1 and OsAPX2 genes encoding the cytosolic forms of the enzyme increased in the whole plant, and so did that of the OsAPX8 gene for the plastid form of the enzyme”
Claim · model-written summary
After post-anoxia, the contribution of plastid OsAPX8 increased in the whole rice plant.
- Taxon
- riceOryza sativat0
- Organ / stage
- whole plante6
- Treatment
- post-anoxiae6
- Gene
- OsAPX8e6
- Outcome
- contributione6
- Direction
- so dide6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Ascorbate-glutathione cycle in wheat and rice seedlings under anoxia and subsequent reaeration”
e6“At post-anoxia, the contribution of the OsAPX1 and OsAPX2 genes encoding the cytosolic forms of the enzyme increased in the whole plant, and so did that of the OsAPX8 gene for the plastid form of the enzyme”
Claim · model-written summary
During reaeration, OsMDAR2 and OsMDAR4 mRNA accumulation was activated in rice shoots and roots.
- Taxon
- riceOryza sativat0
- Organ / stage
- shoots and rootse7
- Treatment
- reaeratione7
- Gene
- OsMDAR2 and OsMDAR4e7
- Outcome
- accumulation of mRNAe7
- Direction
- activatede7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Ascorbate-glutathione cycle in wheat and rice seedlings under anoxia and subsequent reaeration”
e7“The accumulation of mRNA of the genes OsMDAR2 and OsMDAR4 encoding peroxisomal and cytosolic monodehydroascorbate reductase as well as the OsGR2 and OsGR3 for cytosolic and organellar glutathione reductase was activated during reaeration in shoots and roots”
Claim · model-written summary
During reaeration, OsGR2 and OsGR3 mRNA accumulation was activated in rice shoots and roots.
- Taxon
- riceOryza sativat0
- Organ / stage
- shoots and rootse7
- Treatment
- reaeratione7
- Gene
- OsGR2 and OsGR3e7
- Outcome
- accumulation of mRNAe7
- Direction
- activatede7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Ascorbate-glutathione cycle in wheat and rice seedlings under anoxia and subsequent reaeration”
e7“The accumulation of mRNA of the genes OsMDAR2 and OsMDAR4 encoding peroxisomal and cytosolic monodehydroascorbate reductase as well as the OsGR2 and OsGR3 for cytosolic and organellar glutathione reductase was activated during reaeration in shoots and roots”
Claim · model-written summary
In most cases, O2 deficiency activated the genes encoding peroxisomal, plastid and mitochondrial forms of the antioxidant enzymes in wheat and rice.
- Taxon
- wheat and riceOryza sativaTriticum aestivumt0
- Treatment
- O2 deficiencye1
- Outcome
- genes encoding the peroxisomal, plastid, and mitochondrial forms of the enzymese1
- Direction
- activatede1
- Qualifier
- In most casese1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Ascorbate-glutathione cycle in wheat and rice seedlings under anoxia and subsequent reaeration”
e1“In most cases, O2 deficiency activated the genes encoding the peroxisomal, plastid, and mitochondrial forms of the enzymes, and upon reaeration, an enhanced activity of the genes encoding the cytoplasmic forms was observed”
Claim · model-written summary
Upon reaeration, the genes encoding cytoplasmic forms of the antioxidant enzymes showed enhanced activity in wheat and rice.
- Taxon
- wheat and riceOryza sativaTriticum aestivumt0
- Treatment
- upon reaeratione1
- Outcome
- activity of the genes encoding the cytoplasmic formse1
- Direction
- enhancede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Ascorbate-glutathione cycle in wheat and rice seedlings under anoxia and subsequent reaeration”
e1“In most cases, O2 deficiency activated the genes encoding the peroxisomal, plastid, and mitochondrial forms of the enzymes, and upon reaeration, an enhanced activity of the genes encoding the cytoplasmic forms was observed”
Claim · model-written summary
In wheat seedlings, AGC enzymes were inactivated during anoxia and subsequent reaeration.
- Taxon
- wheatTriticum aestivume1
- Organ / stage
- seedlingse1
- Treatment
- anoxia and subsequent reaeratione1
- Outcome
- AGC enzymese1
- Direction
- inactivatione1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Taken together, the inactivation of AGC enzymes was revealed in wheat seedlings during anoxia and subsequent reaeration, which disrupted the effective operation of the cycle and triggered the accumulation of oxidized forms of ascorbate and glutathione”
Claim · model-written summary
The authors suggest that inactivation of AGC enzymes in wheat disrupted the cycle and triggered accumulation of oxidized ascorbate and glutathione.
- Taxon
- wheatTriticum aestivume1
- Outcome
- accumulation of oxidized forms of ascorbate and glutathionee1
- Qualifier
- inactivation of AGC enzymese1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Taken together, the inactivation of AGC enzymes was revealed in wheat seedlings during anoxia and subsequent reaeration, which disrupted the effective operation of the cycle and triggered the accumulation of oxidized forms of ascorbate and glutathione”
Claim · model-written summary
In rice, anoxia maintained the activity of AGC enzymes.
- Taxon
- riceOryza sativae1
- Treatment
- anoxiae1
- Outcome
- activity of AGC enzymese1
- Direction
- maintenancee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“In rice, anoxia led to the maintenance of the activity of AGC enzymes, and reaeration stimulated it, including at the level of gene expression, which ensured the effective operation of AGC”
Claim · model-written summary
In rice, reaeration stimulated the activity of AGC enzymes, including at the level of gene expression.
- Taxon
- riceOryza sativae1
- Treatment
- reaeratione1
- Outcome
- activity of AGC enzymese1
- Direction
- stimulatede1
- Qualifier
- including at the level of gene expressione1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“In rice, anoxia led to the maintenance of the activity of AGC enzymes, and reaeration stimulated it, including at the level of gene expression, which ensured the effective operation of AGC”
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