Purine alkaloid formation in buds and developing leaflets of Coffea arabica: Expression of an optimal defence strategy?
In buds and emergent leaflets of Coffea arabica formation of the purine alkaloids caffeine and theobromine was studies with the aim of characterizing the chemical defence strategy of a tissue with a hight risk of predation. As long as the leaflets are fully covered by a resin layer and by two stipules, their alkaloid content varies between 1 and 3 dry wt. With leaflet emergence, the alkaloid formation increases and the variation decreases. Maximum content of about 4 is reached when the leaflets are fully open. In the subsequent developmental period alkaloid content decreases. A comparison between the investment in alkaloid formation with that in primary metabolic processes demonstrates that chemical defence is costly: influx of carbon atoms into caffeine is 15 of that into respiration. A defence strategy which is based on an antagonism between mechanical and chemical protection is discussed
| Main Authors: | , , |
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| Format: | biblioteca |
| Published: |
1986
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| Subjects: | COFFEA ARABICA, ALCALOIDES, THEOBROMINA, CAFEINA, YEMA (PLANTA), HOJAS, COMPUESTOS ORGANICOS, |
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| Summary: | In buds and emergent leaflets of Coffea arabica formation of the purine alkaloids caffeine and theobromine was studies with the aim of characterizing the chemical defence strategy of a tissue with a hight risk of predation. As long as the leaflets are fully covered by a resin layer and by two stipules, their alkaloid content varies between 1 and 3 dry wt. With leaflet emergence, the alkaloid formation increases and the variation decreases. Maximum content of about 4 is reached when the leaflets are fully open. In the subsequent developmental period alkaloid content decreases. A comparison between the investment in alkaloid formation with that in primary metabolic processes demonstrates that chemical defence is costly: influx of carbon atoms into caffeine is 15 of that into respiration. A defence strategy which is based on an antagonism between mechanical and chemical protection is discussed |
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