Abstract
Plant hormones including cytokinins (CK) are the main signals in root-to-shoot communication and vice versa. Among others, CK antagonize some processes induced by water stress, mainly those mediated by abscisic acid. However, it is still an open question whether the stimulation of stomatal conductance (gs) and in consequence of transpiration rate (E) and net photosynthetic rate (PN) by CK is of general or exceptional character. Therefore, a set of experiments was done aiming to determine how effects of CK on gas exchange parameters depend on CK type and concentration, way of application, and plant species used. The effect of N6-benzyladenine (BA) on bean plants was dependent on concentration and time: in the first hours after application the positive effect on PN was observed at all concentrations used (1, 5, 10, and 20 m M), but after 24 and 72 h only at lower concentrations. The way of application was not decisive: similar effects on gs, E, and PN were found when BA solutions were sprayed on leaves, added to the substrate, or when roots were directly immersed in BA solutions. PN was usually more stimulated than E by BA and therefore WUE was increased. Positive effect of 1 m M BA was also observed during rehydration of water-stressed bean plants. In sugar beet plants, N6-(m-hydroxybenzyl)adenosine (HBA) was tested in addition to BA. However, the effects of both CK in different concentrations (1 - 20 m M) and ways of application were inconsistent, and only rarely the increase in gs, E or PN was observed. Even if these experiments did not prove general stimulation of gas exchange parameters by CK, further preliminary experiments suggested possibilities of alleviation of their inhibition induced by abscisic acid.
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 7
Claim · model-written summary
Benzyladenine increased net photosynthetic rate of bean plants in the first hours after application at all concentrations tested.
- Taxon
- bean plantse0
- Treatment
- N6-benzyladenine (BA)e0
- Outcome
- PNe1
- Direction
- positivee1
- Qualifier
- in the first hours after applicatione1
Not reportedComparator
Verbatim
e0“The effect of N6-benzyladenine (BA) on bean plants was dependent on concentration and time”
e1“in the first hours after application the positive effect on PN was observed at all concentrations used (1, 5, 10, and 20 m M)”
Claim · model-written summary
Benzyladenine increased net photosynthetic rate of bean plants after 24 and 72 h only at lower concentrations.
- Taxon
- bean plantse0
- Treatment
- N6-benzyladenine (BA)e0
- Outcome
- PNe1
- Direction
- positivee1
- Qualifier
- after 24 and 72 h only at lower concentrationse2
Not reportedComparator
Verbatim
e0“The effect of N6-benzyladenine (BA) on bean plants was dependent on concentration and time”
e1“in the first hours after application the positive effect on PN was observed at all concentrations used (1, 5, 10, and 20 m M)”
e2“but after 24 and 72 h only at lower concentrations”
Claim · model-written summary
Spraying on leaves, adding to the substrate or immersing roots gave similar effects of BA on stomatal conductance, transpiration and net photosynthesis in bean.
- Taxon
- bean plantse0
- Treatment
- BA solutions were sprayed on leavese3
- Outcome
- gs, E, and PNe3
- Direction
- similar effectse3
Not reportedComparator
Verbatim
e0“The effect of N6-benzyladenine (BA) on bean plants was dependent on concentration and time”
e3“The way of application was not decisive: similar effects on gs, E, and PN were found when BA solutions were sprayed on leaves, added to the substrate, or when roots were directly immersed in BA solutions”
Claim · model-written summary
BA stimulated net photosynthetic rate of bean plants more than transpiration rate.
Verbatim
e0“The effect of N6-benzyladenine (BA) on bean plants was dependent on concentration and time”
e4“PN was usually more stimulated than E by BA and therefore WUE was increased”
Claim · model-written summary
BA increased water use efficiency of bean plants.
Not reportedComparator
Verbatim
e0“The effect of N6-benzyladenine (BA) on bean plants was dependent on concentration and time”
e4“PN was usually more stimulated than E by BA and therefore WUE was increased”
Claim · model-written summary
A positive effect of 1 mM BA was observed during rehydration of water-stressed bean plants.
- Taxon
- bean plantse5
- Treatment
- 1 m M BAe5
- Outcome
- effecte5
- Direction
- Positivee5
- Qualifier
- during rehydration of water-stressed bean plantse5
Not reportedComparator
Verbatim
e5“Positive effect of 1 m M BA was also observed during rehydration of water-stressed bean plants”
Claim · model-written summary
Benzyladenine and HBA effects on gas exchange in sugar beet were inconsistent, with increases in gs, E or PN rarely observed.
- Taxon
- sugar beet
Beta vulgaris subsp. vulgarise6 - Treatment
- N6-(m-hydroxybenzyl)adenosine (HBA)e6
- Outcome
- gs, E or PNe7
- Direction
- inconsistente7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e6“In sugar beet plants, N6-(m-hydroxybenzyl)adenosine (HBA) was tested in addition to BA”
e7“the effects of both CK in different concentrations (1 - 20 m M) and ways of application were inconsistent, and only rarely the increase in gs, E or PN was observed”
The same questions in other papers
N-benzyladenine · physiology: photosynthesis · Phaseolus vulgaris (common bean)Positive and negative results
5 papers in the same direction as this paper · 1 in the opposite direction
- no effect
- positive
- positive
3 papers more in this group
See all 7 papers →application · physiology: photosynthesis · Phaseolus vulgaris (common bean)Positive and negative results
3 papers in the same direction as this paper · 17 in the opposite direction
- positive
- positive
- positive
17 papers more in this group
See all 21 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.