Growth-Promoting Nitrogen Nutrition Affects Flavonoid Biosynthesis in Young Apple (Malus domestica Borkh.) Leaves
| Autor: | Karl Stich, U. Hoyer, T. Strissel, C. Zistler, Heidrun Halbwirth, Dieter Treutter |
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| Rok vydání: | 2005 |
| Předmět: |
Chalcone synthase
Chalcone isomerase Malus Nitrogen Flavonoid Plant Science chemistry.chemical_compound Botany Flavonol synthase Biomass Ecology Evolution Behavior and Systematics Flavonoids chemistry.chemical_classification biology fungi food and beverages General Medicine biology.organism_classification Plant Leaves Flavonoid biosynthesis chemistry Shoot biology.protein Flavanone Plant Shoots |
| Zdroj: | Plant Biology. 7:677-685 |
| ISSN: | 1438-8677 1435-8603 |
| Popis: | 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". |
| Databáze: | OpenAIRE |
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