Abstract
Using plant growth regulators to alter cytokinin homeostasis with the aim of enhancing endogenous cytokinin levels has been proposed as a strategy to increase yields in wheat and barley. The plant growth regulators INCYDE and CPPU inhibit the cytokinin degrading enzyme cytokinin oxidase/dehydrogenase (CKX), while TD-K inhibits the process of senescence. We report that the application of these plant growth regulators in wheat and barley field trials failed to enhance yields, or change the components of yields. Analyses of the endogenous cytokinin content showed a high concentration of trans-zeatin (tZ) in both wheat and barley grains at four days after anthesis, and statistically significant, but probably biologically insignificant, increases in cisZ-O-glucoside, along with small decreases in cZ riboside (cZR), dihydro Z (DHZ), and DHZR and DHZOG cytokinins, following INCYDE application to barley at anthesis. We discuss possible reasons for the lack of efficacy of the three plant growth regulators under field conditions and comment on future approaches to manipulating yield in the light of the strong homeostatic mechanisms controlling endogenous cytokinin levels.
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Claims 8
Claim · model-written summary
Growth regulator application failed to increase wheat yield or change its yield components.
- Taxon
- wheat
Triticum aestivume0 - Treatment
- these plant growth regulatorse0
- Outcome
- yields, or change the components of yieldse0
- Direction
- failed to enhancee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“application of these plant growth regulators in wheat and barley field trials failed to enhance yields, or change the components of yields”
Claim · model-written summary
Growth regulator application failed to increase barley yield or change its yield components.
- Taxon
- barley
.jpg?width=60)
Hordeum vulgaree0 - Treatment
- these plant growth regulatorse0
- Outcome
- yields, or change the components of yieldse0
- Direction
- failed to enhancee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“application of these plant growth regulators in wheat and barley field trials failed to enhance yields, or change the components of yields”
Claim · model-written summary
Wheat grain had a high trans-zeatin concentration four days after anthesis.
- Taxon
- wheatTriticum aestivume0
- Organ / stage
- grains at four days after anthesise0
- Outcome
- high concentration of trans-zeatin (tZ)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“high concentration of trans-zeatin (tZ) in both wheat and barley grains at four days after anthesis”
Claim · model-written summary
Barley grain had a high trans-zeatin concentration four days after anthesis.
- Taxon
- barleyHordeum vulgaree0
- Organ / stage
- grains at four days after anthesise0
- Outcome
- high concentration of trans-zeatin (tZ)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“high concentration of trans-zeatin (tZ) in both wheat and barley grains at four days after anthesis”
Claim · model-written summary
INCYDE at anthesis significantly increased barley cisZ-O-glucoside, although the authors considered it probably biologically insignificant.
- Taxon
- barleyHordeum vulgaree0
- Treatment
- INCYDE applicatione0
- Outcome
- cisZ-O-glucosidee0
- Direction
- increasese0
- Qualifier
- probably biologically insignificante0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“statistically significant, but probably biologically insignificant, increases in cisZ-O-glucoside, along with small decreases in cZ riboside (cZR), dihydro Z (DHZ), and DHZR and DHZOG cytokinins, following INCYDE application to barley at anthesis”
Claim · model-written summary
INCYDE at anthesis slightly decreased barley cZ riboside.
- Taxon
- barleyHordeum vulgaree0
- Treatment
- INCYDE applicatione0
- Outcome
- cZ riboside (cZR)e0
- Direction
- small decreasese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“small decreases in cZ riboside (cZR), dihydro Z (DHZ), and DHZR and DHZOG cytokinins, following INCYDE application to barley at anthesis”
Claim · model-written summary
INCYDE at anthesis slightly decreased barley dihydro Z.
- Taxon
- barleyHordeum vulgaree0
- Treatment
- INCYDE applicatione0
- Outcome
- dihydro Z (DHZ)e0
- Direction
- small decreasese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“small decreases in cZ riboside (cZR), dihydro Z (DHZ), and DHZR and DHZOG cytokinins, following INCYDE application to barley at anthesis”
Claim · model-written summary
INCYDE at anthesis slightly decreased barley DHZR and DHZOG cytokinins.
- Taxon
- barleyHordeum vulgaree0
- Treatment
- INCYDE applicatione0
- Outcome
- DHZR and DHZOG cytokininse0
- Direction
- small decreasese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“small decreases in cZ riboside (cZR), dihydro Z (DHZ), and DHZR and DHZOG cytokinins, following INCYDE application to barley at anthesis”
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See all 117 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.