REGENERATION IN LOWER PLANTS
LUISE STANGE
Institut für Entwicklungsphysiologie,
Universität zu Köln, Germany
I. Introduction
I l l
II. Reactivation of Quiescent Embryonic Centres
113
III. Embryonization of Mature Cells
116
A. The Changes in the Cells during Embryonization
117
B. The Location of Regeneration
133
C. The Nature of Correlations in Differentiation
138
IV. Differentiation of Regenerates
144
A. Differentiation under Influence of the Isolated Part
_
144
B. Determination Preserved in Regeneration
146
V. Concluding Remarks
150
References
151
I. Introduction
The term 'regeneration' is defined in this chapter as the process by
which living organisms replace lost or artificially isolated parts by new
growth and differentiation and produce in this way a complete or a
repaired individual (cf. Goebel, 1908). Accordingly, defects caused by
external influences are the prerequisites for regenerative processes.
These defects can be of very different magnitudes. In the extreme case,
there may be a single cell of an organism left after destruction or removal of all other cells. The potentiality for regeneration enables the
organism to survive even after severe environmental damage. Regeneration is a term which has been variously defined. In the author's opinion,
one should avoid including under this term normal physiological processes
in which new growth is initiated, such as normal vegetative reproduction
or the formation of secondary meristems and meristemoids in plants.
Although these processes can have many or all developmental features
in common with regeneration proper, the term regeneration would
come to cover, at least in plants, almost the whole range of individual
development and in this way lose its usefulness.
Many different developmental activities are involved in regeneration.
Goebel (1902, 1908) pointed out that the potentialities of the plant,
which are activated in regeneration, are at work in normal development
at other times. For this reason, the reaction of the plant to injuries or
i n
LUISE STANGE
Institut für Entwicklungsphysiologie,
Universität zu Köln, Germany
I. Introduction
I l l
II. Reactivation of Quiescent Embryonic Centres
113
III. Embryonization of Mature Cells
116
A. The Changes in the Cells during Embryonization
117
B. The Location of Regeneration
133
C. The Nature of Correlations in Differentiation
138
IV. Differentiation of Regenerates
144
A. Differentiation under Influence of the Isolated Part
_
144
B. Determination Preserved in Regeneration
146
V. Concluding Remarks
150
References
151
I. Introduction
The term 'regeneration' is defined in this chapter as the process by
which living organisms replace lost or artificially isolated parts by new
growth and differentiation and produce in this way a complete or a
repaired individual (cf. Goebel, 1908). Accordingly, defects caused by
external influences are the prerequisites for regenerative processes.
These defects can be of very different magnitudes. In the extreme case,
there may be a single cell of an organism left after destruction or removal of all other cells. The potentiality for regeneration enables the
organism to survive even after severe environmental damage. Regeneration is a term which has been variously defined. In the author's opinion,
one should avoid including under this term normal physiological processes
in which new growth is initiated, such as normal vegetative reproduction
or the formation of secondary meristems and meristemoids in plants.
Although these processes can have many or all developmental features
in common with regeneration proper, the term regeneration would
come to cover, at least in plants, almost the whole range of individual
development and in this way lose its usefulness.
Many different developmental activities are involved in regeneration.
Goebel (1902, 1908) pointed out that the potentialities of the plant,
which are activated in regeneration, are at work in normal development
at other times. For this reason, the reaction of the plant to injuries or
i n