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Dynamics of reserve substance allocation in the ovule and developing seed of Polycnemum arvense L. (Polycnemaceae, lower core Caryophyllales)статья Исследовательская статья
- Авторы: Veselova T.D., Dzhalilova Kh Kh, Timonin A.C.
- Журнал: Wulfenia
- Том: 25
- Год издания: 2018
- Издательство: Botanischer Garten des Landes Karnten
- Местоположение издательства: Austria
- Аннотация: Seeds of Polycnemum arvense are similar with typical centrosperms in accumulating reservestarch in the perisperm and reserve proteins in the embryo. The developing seed is supplied with precursors of the reserve substances from distant source. Some carbohydrates are deposited as transitory starch in all ovule structures except the core nucellus and in the early embryo. The transitory starch of the exotesta, tegmen, abfunicular epidermis of the nucellus, nucellar cap, abfunicular strand of the nucellus cells and embryo seems to be completely utilized in situ. The transitory starch of the chalaza protrusion, basal body and endotesta is likely to be partly consumed by the developing endosperm and embryo and partly re-deposited in the perisperm as the reserve starch. The perisperm parenchyma dies off thereafter. Starch deposition in the ovule and seed is accordingly two-stepped. The proteins are deposited one-stepped in the embryo to substitute the starch, in the endospermic cap covering radicula and in the exotesta and endotegmen where they are co-precipitated with tannins. The proteins of the embryo are reserve substances. The endospermic cap is functionally similar with the aleurone layer of grass grains. It hydrolyses the reserve starch of perisperm during germination. The proteins deposited in the endospermic cap are likely to be a reserve of necessary hydrolytic enzymes. The proteins coprecipitated with the tannins in the exotesta and endotegmen are evidently neither transitory nor reserve; their function is to be explored. The endosperm transmits nutrients to the developing embryobut it accumulates neither transient nor reserve substances.
- Добавил в систему: Тимонин Александр Константинович