Abstract
Young intact plants of maize (Zea mays L. cv INRA 508) were exposed to 2 to 4 kilopascals partial pressure oxygen (hypoxic pretreatment) for 18 hours before excision of the 5 millimeter root apex and treatment with strictly anaerobic conditions (anoxia). Hypoxic acclimation gave rise to larger amounts of ATP, to larger ATP/ADP and adenylate energy charge ratios, and to higher rates of ethanol production when excised root tips were subsequently made anaerobic, compared with root tips transferred directly from aerobic to anaerobic media. Improved energy metabolism following hypoxic pretreatment was associated with increased activity of alcohol dehydrogenase (ADH), and induction of ADH-2 isozymes. Roots of Adh1(-) mutant plants lacked constitutive ADH and only slowly produced ethanol when made anaerobic. Those that were hypoxically pretreated acclimated to anoxia with induction of ADH2 and a higher energy metabolism, and a rate of ethanol production comparable to that of nonmutants. All these responses were insensitive to the presence or absence of NO(3) (-). Additionally, the rate of ethanol production was about 50 times greater than the rate of reduction of NO(3) (-) to NO(2) (-). These results indicate that nitrate reductase does not compete effectively with ADH for NADH, or contribute to energy metabolism during anaerobic respiration in this tissue through nitrate reduction. Unacclimated root tips of wild type and Adhl(-) mutants appeared not to survive more than 8 to 9 hours in strict anoxia; when hypoxically pretreated they tolerated periods under anoxia in excess of 22 hours.
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 15
Claim · model-written summary
Hypoxic pretreatment increased ATP in anaerobic root tips.
- Organ / stage
- root tipse0
- Treatment
- Hypoxic acclimatione0
- Outcome
- amounts of ATPe0
- Direction
- largere0
- Comparator
- root tips transferred directly from aerobic to anaerobic mediae0
Zea maysOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Hypoxic acclimation gave rise to larger amounts of ATP, to larger ATP/ADP and adenylate energy charge ratios, and to higher rates of ethanol production when excised root tips were subsequently made anaerobic, compared with root tips transferred directly from aerobic to anaerobic media.”
t0“Zea mays”
Claim · model-written summary
Hypoxic pretreatment increased ATP/ADP and adenylate energy charge ratios.
- Treatment
- Hypoxic acclimatione0
- Outcome
- ATP/ADP and adenylate energy charge ratiose0
- Direction
- largere0
- Comparator
- root tips transferred directly from aerobic to anaerobic mediae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Hypoxic acclimation gave rise to larger amounts of ATP, to larger ATP/ADP and adenylate energy charge ratios, and to higher rates of ethanol production when excised root tips were subsequently made anaerobic, compared with root tips transferred directly from aerobic to anaerobic media.”
t0“Zea mays”
Claim · model-written summary
Hypoxic pretreatment raised anaerobic ethanol production.
- Treatment
- Hypoxic acclimatione0
- Outcome
- rates of ethanol productione0
- Direction
- highere0
- Comparator
- root tips transferred directly from aerobic to anaerobic mediae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Hypoxic acclimation gave rise to larger amounts of ATP, to larger ATP/ADP and adenylate energy charge ratios, and to higher rates of ethanol production when excised root tips were subsequently made anaerobic, compared with root tips transferred directly from aerobic to anaerobic media.”
t0“Zea mays”
Claim · model-written summary
Acclimated root tips had increased ADH activity.
- Gene
- alcohol dehydrogenase (ADH)e0
- Outcome
- activity of alcohol dehydrogenase (ADH)e0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Improved energy metabolism following hypoxic pretreatment was associated with increased activity of alcohol dehydrogenase (ADH), and induction of ADH-2 isozymes.”
t0“Zea mays”
Claim · model-written summary
Hypoxic pretreatment induced ADH-2 isozymes.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Improved energy metabolism following hypoxic pretreatment was associated with increased activity of alcohol dehydrogenase (ADH), and induction of ADH-2 isozymes.”
t0“Zea mays”
Claim · model-written summary
Adh1 mutant roots lacked constitutive ADH.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Roots of Adh1(-) mutant plants lacked constitutive ADH and only slowly produced ethanol when made anaerobic.”
t0“Zea mays”
Claim · model-written summary
Adh1 mutant roots produced ethanol slowly under anoxia.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Roots of Adh1(-) mutant plants lacked constitutive ADH and only slowly produced ethanol when made anaerobic.”
t0“Zea mays”
Claim · model-written summary
Hypoxically pretreated mutant roots induced ADH2.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Those that were hypoxically pretreated acclimated to anoxia with induction of ADH2 and a higher energy metabolism, and a rate of ethanol production comparable to that of nonmutants.”
t0“Zea mays”
Claim · model-written summary
Hypoxically pretreated mutant roots had higher energy metabolism.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Those that were hypoxically pretreated acclimated to anoxia with induction of ADH2 and a higher energy metabolism, and a rate of ethanol production comparable to that of nonmutants.”
t0“Zea mays”
Claim · model-written summary
Hypoxically pretreated mutants produced ethanol at a rate comparable to nonmutants.
- Treatment
- hypoxically pretreatede0
- Outcome
- rate of ethanol productione0
- Direction
- comparablee0
- Comparator
- nonmutantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Those that were hypoxically pretreated acclimated to anoxia with induction of ADH2 and a higher energy metabolism, and a rate of ethanol production comparable to that of nonmutants.”
t0“Zea mays”
Claim · model-written summary
Responses were insensitive to nitrate presence.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“All these responses were insensitive to the presence or absence of NO(3) (-).”
t0“Zea mays”
Claim · model-written summary
Ethanol production rate was about 50 times nitrate reduction rate.
- Outcome
- rate of ethanol productione0
- Direction
- greatere0
- Value
- about 50 timese0
- Comparator
- rate of reduction of NO(3) (-) to NO(2) (-)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the rate of ethanol production was about 50 times greater than the rate of reduction of NO(3) (-) to NO(2) (-).”
t0“Zea mays”
Claim · model-written summary
Nitrate reductase was inferred not to compete effectively with ADH for NADH or support anaerobic energy metabolism through nitrate reduction.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“nitrate reductase does not compete effectively with ADH for NADH, or contribute to energy metabolism during anaerobic respiration in this tissue through nitrate reduction.”
t0“Zea mays”
Claim · model-written summary
Unacclimated root tips appeared not to survive beyond 8 to 9 hours of anoxia.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Unacclimated root tips of wild type and Adhl(-) mutants appeared not to survive more than 8 to 9 hours in strict anoxia”
t0“Zea mays”
Claim · model-written summary
Hypoxically pretreated root tips tolerated more than 22 hours of anoxia.
- Treatment
- hypoxically pretreatede0
- Outcome
- tolerated periods under anoxiae0
- Direction
- in excess ofe0
- Value
- 22 hourse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“when hypoxically pretreated they tolerated periods under anoxia in excess of 22 hours.”
t0“Zea mays”
The same questions in other papers
flooding · molecular: metabolites · Zea mays (maize)Positive and negative results
5 papers in the same direction as this paper · 13 in the opposite direction · 1 reporting no difference from an alternative
- positive
- negative
- no effect
16 papers more in this group
See all 20 papers →flooding · yield · Zea mays (maize)Positive and negative results
5 papers in the same direction as this paper · 50 in the opposite direction
- negative
- negative
- negative
52 papers more in this group
See all 56 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.