Abstract
During flooding, when roots are submerged in oxygen‐free water, root tissue becomes hypoxic and its metabolism is characterized by fermentation processes and limited respiratory activity. After returning to aerobic conditions (post‐hypoxic period) high respiration rates together with symptoms of oxidative stress are observed. Plant mitochondria have two terminal oxidases: a cytochrome oxidase with high affinity to oxygen and an alternative (cyanide resistant) oxidase (AOX) with a relatively low oxygen affinity. We compared mitochondrial respiration and AOX expression immediately after hypoxic and during post‐hypoxic period. Four‐day‐old barley ( Hordeum vulgare L. cv Gregor) seedlings were transferred for 5 days to Knop nutrient medium flushed with air (control) or nitrogen (hypoxia) and after returned for 24 h to aerated nutrient medium (post‐hypoxia). NADH/NAD + + NADH and UQH 2 /UQ total ratios increased in hypoxia‐treated roots. After the hypoxic roots were returned to aerated medium, increases in respiration rate and ATP concentration were observed. Mitochondria isolated from barley roots at the end of hypoxic period exhibited high respiratory rates as compared to mitochondria from control and post‐hypoxic roots. Control root mitochondria expressed high AOX capacity in the presence of pyruvate and DTT. Mitochondria isolated at the end of the hypoxic period were highly cyanide sensitive under AOX‐activating conditions, however, after 24 h of post‐hypoxia, AOX capacity was comparable to that observed in the control. The capacity of AOX was correlated with the amount of AOX protein determined by Western blotting. Faint or no bands were observed immediately after hypoxia with the AOX protein appearing again during the post‐hypoxic period. Examination of AOX transcript levels showed no significant differences between control, hypoxic and post‐hypoxic roots indicating that the regulation of AOX expression by oxygen availability in barley roots may take place at the translation level.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 12
Claim · model-written summary
Hypoxia increased NADH and UQH2 ratios in barley roots.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“NADH/NAD + + NADH and UQH 2 /UQ total ratios increased in hypoxia‐treated roots”
e1“Four‐day‐old barley ( Hordeum vulgare L. cv Gregor) seedlings”
Claim · model-written summary
Returning hypoxic roots to aerated medium increased respiration rate.
- Taxon
- barley
.jpg?width=60)
Hordeum vulgaree0e1 - Organ / stage
- rootse0
- Treatment
- returned to aerated mediume0
- Direction
- increasese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“After the hypoxic roots were returned to aerated medium, increases in respiration rate and ATP concentration were observed”
e1“Four‐day‐old barley ( Hordeum vulgare L. cv Gregor) seedlings”
Claim · model-written summary
Returning hypoxic roots to aerated medium increased ATP concentration.
- Taxon
- barleyHordeum vulgaree0e1
- Organ / stage
- rootse0
- Treatment
- returned to aerated mediume0
- Direction
- increasese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“After the hypoxic roots were returned to aerated medium, increases in respiration rate and ATP concentration were observed”
e1“Four‐day‐old barley ( Hordeum vulgare L. cv Gregor) seedlings”
Claim · model-written summary
Mitochondria isolated after hypoxia had higher respiratory rates than control and recovered mitochondria.
- Taxon
- barleyHordeum vulgaree0e1
- Organ / stage
- rootse0
- Direction
- highe0
- Comparator
- control and post‐hypoxic rootse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Mitochondria isolated from barley roots at the end of hypoxic period exhibited high respiratory rates as compared to mitochondria from control and post‐hypoxic roots”
e1“Four‐day‐old barley ( Hordeum vulgare L. cv Gregor) seedlings”
Claim · model-written summary
Control root mitochondria showed high AOX capacity with pyruvate and DTT.
- Taxon
- barleyHordeum vulgaree0e1
- Organ / stage
- roote0
- Gene
- AOXe0
- Direction
- highe0
- Qualifier
- in the presence of pyruvate and DTTe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Control root mitochondria expressed high AOX capacity in the presence of pyruvate and DTT”
e1“Four‐day‐old barley ( Hordeum vulgare L. cv Gregor) seedlings”
Claim · model-written summary
Mitochondria after hypoxia were highly cyanide sensitive under AOX-activating conditions.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Mitochondria isolated at the end of the hypoxic period were highly cyanide sensitive under AOX‐activating conditions”
e1“Four‐day‐old barley ( Hordeum vulgare L. cv Gregor) seedlings”
Claim · model-written summary
AOX capacity after 24 hours of recovery was comparable to control.
- Taxon
- barleyHordeum vulgaree0e1
- Gene
- AOXe0
- Direction
- comparablee0
- Qualifier
- after 24 h of post‐hypoxiae0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“after 24 h of post‐hypoxia, AOX capacity was comparable to that observed in the control”
e1“Four‐day‐old barley ( Hordeum vulgare L. cv Gregor) seedlings”
Claim · model-written summary
AOX capacity correlated with AOX protein abundance.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The capacity of AOX was correlated with the amount of AOX protein determined by Western blotting”
e1“Four‐day‐old barley ( Hordeum vulgare L. cv Gregor) seedlings”
Claim · model-written summary
AOX protein bands were faint or absent immediately after hypoxia.
- Taxon
- barleyHordeum vulgaree0e1
- Gene
- AOXe0
- Qualifier
- immediately after hypoxiae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Faint or no bands were observed immediately after hypoxia with the AOX protein appearing again during the post‐hypoxic period”
e1“Four‐day‐old barley ( Hordeum vulgare L. cv Gregor) seedlings”
Claim · model-written summary
AOX protein reappeared during the post-hypoxic period.
- Taxon
- barleyHordeum vulgaree0e1
- Gene
- AOXe0
- Qualifier
- during the post‐hypoxic periode0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“AOX protein appearing again during the post‐hypoxic period”
e1“Four‐day‐old barley ( Hordeum vulgare L. cv Gregor) seedlings”
Claim · model-written summary
AOX transcript levels did not differ significantly between control, hypoxic and recovered roots.
- Taxon
- barleyHordeum vulgaree0e1
- Gene
- AOXe0
- Direction
- no significant differencese0
- Comparator
- control, hypoxic and post‐hypoxic rootse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“AOX transcript levels showed no significant differences between control, hypoxic and post‐hypoxic roots”
e1“Four‐day‐old barley ( Hordeum vulgare L. cv Gregor) seedlings”
Claim · model-written summary
Authors inferred oxygen regulation of AOX expression may occur at translation.
- Taxon
- barleyHordeum vulgaree0e1
- Gene
- AOXe0
- Qualifier
- at the translation levele0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“regulation of AOX expression by oxygen availability in barley roots may take place at the translation level”
e1“Four‐day‐old barley ( Hordeum vulgare L. cv Gregor) seedlings”
The same questions in other papers
in vitro · molecular: metabolites · Hordeum vulgare (barley)Positive and negative results
5 papers in the same direction as this paper · 3 in the opposite direction
- no effect
- no effect
- no effect
5 papers more in this group
See all 9 papers →flooding · molecular: metabolites · Hordeum vulgare (barley)Positive and negative results
7 papers in the same direction as this paper · 4 in the opposite direction
- positive
- positive
- positive
8 papers more in this group
See all 12 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.