Naslov
Developing fruit direct post-floral morphogenesis in Helleborus niger L.

Autori
Salopek-Sondi, Branka ; Kovač, Maja ; Prebeg, Tatjana ; Magnus, Volker

Izvornik
Journal of Experimental Botany (0022-0957) 53 (2002), 376; 1949-1957

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Christmas rose; cytokinin analysis; Helleborus niger L.; plant growth regulator; post-floral morphogenesis

Sažetak
In fertilized flowers of Helleborus niger L., the sepals (the showy elements of the perianth at anthesis) grow, spread, and turn green, and the peduncles elongate. These processes did not proceed to completion when the pistils were removed at the bud stage, but could be restored by the application of plant growth regulators. Cytokinins and gibberellins stimulated the formation of well-developed chloroplasts in, and spreading of, the sepals ; the gibberellin, GA3, and the auxin, 4-chloroindole-3-acetic acid, promoted peduncle elongation. In fruit-bearing flowers, on the other hand, paclobutrazol, an inhibitor of gibberellin biosynthesis, reduced chlorophyll formation in the sepals, reversed sepal spreading, and inhibited peduncle elongation. Of the endogenous growth regulators in developing fruit, the following cytokinins were identified: zeatin, dihydrozeatin, N-6-(2-isopentenyl)adenine and their ribosides and 9-glucosides. Zeatin riboside drastically increased in abundance (about 200 times), shortly after fertilization, when chlorophyll accumulation in the sepals occurred at the fastest rate, and remained the most prominent identified cytokinin until seed ripening.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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