ISSN:
1432-2048
Keywords:
Key words: Abscisic acid –Daucus (embryogenesis, stress) – Epidermal cells – Somatic embryogenesis – Stress
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract. Seedlings of carrot (Daucus carota L. cv. Red Cored Chantenay) formed somatic embryos when cultured on medium containing abscisic acid (ABA) as the sole source of growth regulator. The number of embryos per number of seedlings changed depending on the concentration of ABA added to the medium, with a maximum embryo number at 1 × 10−4 M ABA. Seedling age was critical for response to exogenous ABA; no seedling with a hypocotyl longer than 3.0 cm was able to form an embryo. Removal of shoot apices from seedlings completely inhibited the embryogenesis induced by application of exogenous ABA, suggesting that the action of ABA requires some substance(s) that is translocated basipetally from shoot apices through hypocotyls. Histologically, somatic embryos shared common epidermal cells and differentiated not through the formation of embryogenic cell clumps, but directly from epidermal cells. These morphological traits are distinct from those of embryogenesis via formation of embryogenic cell clumps, which has been found in embryogenic carrot cultures established using 2,4-dichlorophenoxyacetic acid or other auxins. These results suggest that ABA acts as a signal substance in stress-induced carrot seedling somatic embryogenesis.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004250000387
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