A stage-specific block is produced in carrot somatic embryos by 1,2-benzisoxazole-3-acetic acid

Morphogenetic effects of Brefeldin A on embryogenic cell cultures of Daucus carota L.

“…4). The latter are irregularly shaped forms arising from the recurrent production of globular masses by protodermal cells dividing at the surface of a blocked globular form (see Baldan et al 1995).…”

“…The globular stage was already known to be the most sensitive developmental stage (Zimmermann et al 1989) and treatments with inhibitors as diverse as benz-isoxazole acetic acid (an auxin analogue; Baldan et al 1995) or 2-amino-5-ethoxycarbohyl-pyrimidine (a polysubstituted pyrimidine causing hypomethylation, Lo Schiavo et al 1989) all caused a block at the globular stage and the production of polyembryos. The temperature-sensitive carrot cell mutant ts11 showed sensitivity at the non-permissive temperature at the globular stage (Lo Schiavo et al 1990).…”

Inhibitory Effects of p-Hydroxybenzyl Alcohol on Somatic Embryogenesis in Carrot Cell Cultures.

“…Thus, it appears that p-hydroxybenzoic acid is not essential for the inhibition of somatic embryogenesis in high -cell-density cultures. Certain other chemicals specifically interrupt the transition from heartshaped embryos to torpedo-shaped embryos (LoSchiavo et al, 1986;Baldan et al, 1995;Capitano et al, 1997). In contrast, p-hydroxybenzyl alcohol markedly reduced the number of somatic embryos but a few somatic embryos develop into mature embryos (Fig.…”

“…The inhibitory factors appear to suppress only the exceptionally rapid division of cells that is characteristic of the early stages of somatic embryogenesis (Kobayashi et al, 1999b). Such inhibitory endogenous factors were different from the natural and chemically synthesized factors that have been shown to inhibit the formation of somatic embryos (LoSciavo et al,1986;Baldan et al,1995;Capitano et al, 1997;Toonen et al, 1997). We identified one of the inhibitory endogenous factors as p-hydroxybenzyl alcohol (Kobayashi et al, unpublished data), but the physiological actions of p-hydroxybenzyl alcohol remain to be characterized.…”

Development of the embryo proper and the suspensor during plant embryogenesis

“…Some conditioning factors suppress somatic embryogenesis in Japanese larch by blocking the development of the suspensor under high-cell-density conditions (Umehara et al 2004a). No inhibitory factors have been isolated from this species, although several synthetic and natural compounds have been isolated from carrot somatic embryos (Fridborg et al 1978;LoSciavo et al 1986;Baldan et al 1995;Capitano et al 1997;Kobayashi et al 2000a). We purified and chemically characterized a novel inhibitory conditioning factor, vanillyl benzyl ether (VBE), from the embryogenic culture medium of this species (Umehara et al 2005a).…”