Abstract
BACKGROUND AND AIMS: Anoxia leads to an energy crisis, tolerance of which varies from plant to plant. Although the apoplast represents an important storage and reaction space, and engages in the mediation of membrane transport, this extracellular compartment has not yet been granted a role during oxygen shortage. Here, an attempt is made to highlight the importance of the apoplast during oxygen stress and to test whether information about it is transferred systemically in Hordeum vulgare. METHODS: Non-invasive ion-selective microprobes were used which, after being inserted through open stomata, directly contact the apoplastic fluid and continuously measure the apoplastic pH and changes to it. KEY RESULTS: (a) Barley leaves respond to oxygen stress with apoplastic alkalinization and membrane depolarization. These responses are persistent under anoxia (N2; O2 < 3%) but transient under hypoxia. (b) Being applied to the root, the information 'anoxia' is signalled to the leaf as an increase in pH, whereas 'hypoxia' is not: flooding of the roots within the first 2 h has no effect on the leaf apoplastic pH, whereas anoxia (N2) or chemical anoxia (NaCN/salicylic hydroxamic acid) rapidly increase the leaf apoplastic pH. (c) Under anoxia, the proton motive force suffers a decrease by over 70 %, which impairs H(+) -driven transport. CONCLUSIONS: Although anoxia-induced apoplastic alkalinization is a general response to stress, its impact on the proton motive force (reduction) and thus on transport mediation of energy-rich compounds is evident. It is concluded that anoxia tolerance depends on how the plant is able to hold the proton motive force and H(+) turnover at a level that guarantees sufficient energy is harvested to overcome the crisis.
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 6
Claim · model-written summary
Barley leaves alkalinized the apoplast and depolarized membranes under oxygen stress.
- Taxon
- Barley
.jpg?width=60)
Hordeum vulgaree0 - Treatment
- oxygen stresse0
- Outcome
- apoplastic alkalinization and membrane depolarizatione0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“Barley leaves respond to oxygen stress with apoplastic alkalinization and membrane depolarization”
Claim · model-written summary
The leaf responses persisted under anoxia but were transient under hypoxia.
- Taxon
- BarleyHordeum vulgaret0
- Outcome
- These responsese0
- Qualifier
- persistent under anoxia (N2; O2 < 3%) but transient under hypoxiae0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“These responses are persistent under anoxia (N2; O2 < 3%) but transient under hypoxia”
t0“Barley”
Claim · model-written summary
Root flooding during the first two hours did not change leaf apoplastic pH.
- Taxon
- BarleyHordeum vulgaret0
- Treatment
- flooding of the rootse0
- Outcome
- leaf apoplastic pHe0
- Direction
- no effecte0
- Qualifier
- within the first 2 he0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“flooding of the roots within the first 2 h has no effect on the leaf apoplastic pH”
t0“Barley”
Claim · model-written summary
Root anoxia or chemical anoxia rapidly increased leaf apoplastic pH.
- Taxon
- BarleyHordeum vulgaret0
- Treatment
- anoxia (N2) or chemical anoxia (NaCN/salicylic hydroxamic acid)e0
- Outcome
- leaf apoplastic pHe0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“anoxia (N2) or chemical anoxia (NaCN/salicylic hydroxamic acid) rapidly increase the leaf apoplastic pH”
t0“Barley”
Claim · model-written summary
Anoxia decreased proton motive force by over 70 %.
- Taxon
- BarleyHordeum vulgaret0
- Treatment
- anoxiae0
- Outcome
- proton motive forcee0
- Direction
- decreasee0
- Value
- over 70 %e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under anoxia, the proton motive force suffers a decrease by over 70 %”
t0“Barley”
Claim · model-written summary
Loss of proton motive force under anoxia impairs proton-driven transport.
- Taxon
- BarleyHordeum vulgaret0
- Outcome
- H(+) -driven transporte0
- Qualifier
- proton motive force suffers a decreasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the proton motive force suffers a decrease by over 70 %, which impairs H(+) -driven transport”
t0“Barley”
The same questions in other 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.