Abstract
Enhanced shoot growth and a decrease in flavonoid concentration in apple trees grown under high nitrogen (N) supply was observed in previous studies, along with increasing scab susceptibility of cultivar "Golden Delicious" after high N nutrition. Several hypotheses have suggested that there is a trade-off between primary and secondary metabolism because of competition for common substrates, but nothing is known about regulation at the enzyme level. In this study, a set of experiments was performed to elucidate the effect of N nutrition on the activities of key enzymes involved in flavonoid biosynthesis (phenylalanine ammonia-lyase [PAL], chalcone synthase/chalcone isomerase [CHS/CHI}, flavanone 3-hydroxylase [FHT], flavonol synthase [FLS], dihydroflavonol 4-reductase [DFR]) and the accumulation of different groups of phenylpropanoids. The inhibition of flavonoid accumulation by high N nutrition could be confirmed, but the influence of N supply on the flavonoid enzymes CHS/CHI, FHT, DFR, and FLS was not evident. However, PAL activity seems to be downregulated, thus forming a bottleneck resulting in a generally decreased flavonoid accumulation. Furthermore, the response of the scab-resistant cultivar "Rewena" to high N nutrition was not as strong as that of the susceptible cultivar "Golden Delicious".
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Claims 6
Claim · model-written summary
High nitrogen nutrition inhibited flavonoid accumulation in young apple leaves.
- Taxon
- Malus domestica
Malus domesticat0 - Treatment
- high N nutritione1
- Outcome
- flavonoid accumulatione1
- Direction
- decreaseinferrede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Young Apple (Malus domestica Borkh.) Leaves”
e1“The inhibition of flavonoid accumulation by high N nutrition could be confirmed”
Claim · model-written summary
N supply had no evident effect on the flavonoid enzymes CHS/CHI, FHT and DFR in apple leaves.
- Taxon
- Malus domesticaMalus domesticat0
- Treatment
- N supplye2
- Outcome
- flavonoid enzymes CHS/CHI, FHT, DFRe2
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Young Apple (Malus domestica Borkh.) Leaves”
e2“the influence of N supply on the flavonoid enzymes CHS/CHI, FHT, DFR, and FLS was not evident”
Claim · model-written summary
N supply had no evident effect on the flavonoid enzyme FLS in apple leaves.
- Taxon
- Malus domesticaMalus domesticat0
- Treatment
- N supplye2
- Outcome
- FLSe2
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Young Apple (Malus domestica Borkh.) Leaves”
e2“the influence of N supply on the flavonoid enzymes CHS/CHI, FHT, DFR, and FLS was not evident”
Claim · model-written summary
High nitrogen nutrition downregulated PAL activity in apple leaves.
- Taxon
- Malus domesticaMalus domesticat0
- Treatment
- high N nutritione1
- Outcome
- PAL activitye3
- Direction
- downregulatede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Young Apple (Malus domestica Borkh.) Leaves”
e1“The inhibition of flavonoid accumulation by high N nutrition could be confirmed”
e3“However, PAL activity seems to be downregulated, thus forming a bottleneck resulting in a generally decreased flavonoid accumulation”
Claim · model-written summary
PAL downregulation forms a bottleneck that leads to decreased flavonoid accumulation under high nitrogen.
- Taxon
- Malus domesticaMalus domesticat0
- Gene
- PALe3
- Outcome
- flavonoid accumulatione3
- Qualifier
- bottlenecke3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Young Apple (Malus domestica Borkh.) Leaves”
e3“However, PAL activity seems to be downregulated, thus forming a bottleneck resulting in a generally decreased flavonoid accumulation”
Claim · model-written summary
The scab-resistant cultivar Rewena responded less than the susceptible cultivar Golden Delicious to high nitrogen nutrition.
- Taxon
- Malus domesticaMalus domesticat0
- Material
- Rewenae4
- Treatment
- high N nutritione4
- Outcome
- responsee4
- Direction
- lowerinferrede4
- Comparator
- Golden Deliciouse4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Young Apple (Malus domestica Borkh.) Leaves”
e4“the response of the scab-resistant cultivar "Rewena" to high N nutrition was not as strong as that of the susceptible cultivar "Golden Delicious"”
The same questions in other papers
nitrogen · physiology: enzyme activity · Malus domestica (apple)Positive and negative results
2 in the opposite direction
- positive
- positive
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.