Growth and development of totipotent cells: some problems, procedures, and perspectives
1970
Steward, F.C. | Ammirato, P.V. | Mapes, M.O.
This paper presents a comprehensive account of the growth of free cells in liquid culture and the various stages of their subsequent morphogenesis. A number of examples are selected for detailed description. These show that somatic cells may recapitulate embryogeny, and that they will do so in very large numbers under the appropriate conditions. This is illustrated for several members of the Umbelliferae. The importance of both synergistic combinations of stimuli and their appropriate sequential application in the ambient medium is stressed. The range of growth forms that arise from manipulating the external medium is illustrated for the carrot plant. In a number of other examples vigorous cell cultures have been obtained showing varying degrees of organization, but nevertheless, they have proved more recalcitrant from the standpoint of their morphogenesis. The conclusion is that, in principle, all normally diploid somatic cells are essentially totipotent and that present failures to rear them into plants merely present the challenge to find the right conditions for their development. When cells readily develop into embryos and into plants they seem to do so via cotyledons as their absorbing organs in situations in which the role of suspensors is at a minimum. Since this work dramatizes the causal problems presented by development and differentiation, these questions are discussed. This discussion is undertaken from the standpoint of morphology and the behaviour of cells on the one hand and the potential application of free cell cultures in research and technology on the other.
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