Abstract
Prohexadione-Ca (BAS 125 W) is a new growth retardant for the inhibition of excessive vegetative growth in apple and other plant species. From work with enzyme preparations, it is known that prohexadione-Ca mimics 2-oxoglutaric acid, the co-substrate of dioxygenases, which catalyze late steps in gibberellin (GA) biosynthesis. As a result, the formation of growth-active GAs is reduced. In order to have a better understanding of its effects in intact plants, we have analyzed the GA status of treated and untreated apple plantlets. In a typical experiment, the following results were obtained: Plants (cv. Jonagold on M9 at 19 cm of new shoot growth) were sprayed until run-off with an aqueous preparation containing 25 ppm of active ingredient. After 22 days of cultivation under greenhouse conditions, total new shoot growth of the controls and the treated plants was 55 cm and 44 cm, respectively. In the apical part of this material the following GAs (roughly ordered in biosynthetic sequence) were detected at the following levels (control/treated in microgram per kilogram dry weight): GA 19 (31/62), GA29 (24/36), GA20 (11/20), GA1 (4/3), and GA 8 (8/3). These results clearly demonstrate that prohexadione-Ca blocks primarily the hydroxylation of GA 20 into GA 1 . This leads to reduced levels of the highly active GA 1 and of GA 8 , its inactive metabolite, whereas GA 20 and the other inactive precursors accumulate. The data support older observations obtained in vitro, which indicate that GA 20 3β-hydroxylase and related dioxygenases are the primary targets of prohexadione-Ca and similar compounds.
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Claims 8
Claim · model-written summary
total new shoot growth of the controls and the treated plants was 55 cm and 44 cm, respectively
- Taxon
- Apple
Malus domesticat0 - Organ / stage
- new shoote0
- Treatment
- Prohexadione-Cat0
- Outcome
- total new shoot growthe0
- Direction
- decreaseinferrede0
- Value
- 44 cme0
- Comparator
- controlse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“total new shoot growth of the controls and the treated plants was 55 cm and 44 cm, respectively”
t0“Prohexadione-Ca on Gibberellin Levels in Young Apple Shoots”
Claim · model-written summary
GA 19 (31/62)
- Taxon
- AppleMalus domesticat0
- Treatment
- Prohexadione-Cat0
- Outcome
- GA 19e0
- Direction
- increaseinferrede0
- Value
- 31/62e0
- Comparator
- controle1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GA 19 (31/62)”
t0“Prohexadione-Ca on Gibberellin Levels in Young Apple Shoots”
e1“control/treated in microgram per kilogram dry weight”
Claim · model-written summary
GA29 (24/36)
- Taxon
- AppleMalus domesticat0
- Treatment
- Prohexadione-Cat0
- Outcome
- GA29e0
- Direction
- increaseinferrede0
- Value
- 24/36e0
- Comparator
- controle1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GA29 (24/36)”
t0“Prohexadione-Ca on Gibberellin Levels in Young Apple Shoots”
e1“control/treated in microgram per kilogram dry weight”
Claim · model-written summary
GA20 (11/20)
- Taxon
- AppleMalus domesticat0
- Treatment
- Prohexadione-Cat0
- Outcome
- GA20e0
- Direction
- increaseinferrede0
- Value
- 11/20e0
- Comparator
- controle1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GA20 (11/20)”
t0“Prohexadione-Ca on Gibberellin Levels in Young Apple Shoots”
e1“control/treated in microgram per kilogram dry weight”
Claim · model-written summary
GA1 (4/3)
- Taxon
- AppleMalus domesticat0
- Treatment
- Prohexadione-Cat0
- Outcome
- GA1e0
- Direction
- decreaseinferrede0
- Value
- 4/3e0
- Comparator
- controle1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GA1 (4/3)”
t0“Prohexadione-Ca on Gibberellin Levels in Young Apple Shoots”
e1“control/treated in microgram per kilogram dry weight”
Claim · model-written summary
GA 8 (8/3)
- Taxon
- AppleMalus domesticat0
- Treatment
- Prohexadione-Cat0
- Outcome
- GA 8e0
- Direction
- decreaseinferrede0
- Value
- 8/3e0
- Comparator
- controle1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GA 8 (8/3)”
t0“Prohexadione-Ca on Gibberellin Levels in Young Apple Shoots”
e1“control/treated in microgram per kilogram dry weight”
Claim · model-written summary
prohexadione-Ca blocks primarily the hydroxylation of GA 20 into GA 1
- Taxon
- appleMalus domesticae1
- Treatment
- prohexadione-Cae0
- Outcome
- hydroxylation of GA 20 into GA 1e0
- Direction
- blockse0
- Qualifier
- primarilye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“prohexadione-Ca blocks primarily the hydroxylation of GA 20 into GA 1”
e1“apple plantlets”
Claim · model-written summary
GA 20 3β-hydroxylase and related dioxygenases are the primary targets of prohexadione-Ca and similar compounds
- Taxon
- appleMalus domesticae1
- Treatment
- prohexadione-Cae0
- Gene
- GA 20 3β-hydroxylasee0
- Outcome
- primary targetse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GA 20 3β-hydroxylase and related dioxygenases are the primary targets of prohexadione-Ca and similar compounds”
e1“apple plantlets”
The same questions in other papers
prohexadione · growth · Malus domestica (apple)Positive and negative results
11 papers in the same direction as this paper · 3 in the opposite direction
- negative
- no effect
- negative
11 papers more in this group
See all 15 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.