1062-3604/03/3404- $25.00 © 2003
Russian Journal of Developmental Biology, Vol. 34, No. 4, 2003, pp. 205–212. Translated from Ontogenez, Vol. 34, No. 4, 2003, pp. 253–261.
Original Russian Text Copyright © 2003 by Ivanov.
At ﬁrst sight, it is not clear whether there are stem
cells in plants. Under the conditions of tissue culture,
the normal plant can be obtained from any living differ-
entiated cell. During vegetative propagation, a new
plant can arise from a deﬁnitive cell that terminated its
growth or several cells, from one or several tissues.
Hence, all plant cells are totipotent and an entire plant
can be formed from each cell. This process is regulated
by a system of cell interactions through the synthesis
and transport of phytohormones and other compounds.
Nevertheless, during the period of growth of the axial
organs of a plant, the cells are distinguished which
resemble the stem cells of animals in some features and
which are considered as stem cells.
The most apical cells of meristems are called stem
cells in plants (Ivanov, 1974, 1981, 1986, 1987; Barlow,
1978, 1997; Francis, 1997; Gross-Hardt and Laux,
2003). Unlike most meristem cells which are elongated
within several divisions and differentiated, the stem
cells remain in the meristem during the entire period of
axis growth. However, unlike vertebrate animals, they
can arise repeatedly during growth and morphogenesis
from the already differentiated cells. Although the
striking examples of tissue plasticity in vertebrates
have recently been described (Holden and Vogel,
2002), the capacity of formation of the entire plant from
differentiated cells is more pronounced. There is now
self-supporting population of stem cells in plants, sim-
ilar to the embryonic stem cells in animals, but the stem
cells arising during formation of a new axis, shoot or
This paper was written for the special issue of the journal dedi-
cated to the problem of stem cells (
Rus. J. Devel. Biol.
vol. 34, no. 3).
The author dedicates this paper to the memory of Prof.
A.A. Zavarzin with whom he discussed repeatedly the problem of
root, are maintained and regulated and function accord-
ing to the same principles as in animals (see
Gross Hardt and Laux, 2003). In some respects, the
studies of the patterns of these processes are simpler in
plants, in which the stem cells or the cells that are con-
sidered as stem cells with the above restrictions are eas-
ily identiﬁed on sections. In addition, gene markers are
known for these cells in the shoot apical meristems
, 1997; Schoof
, 2000; Clark, 2001;
Gross-Hardt and Laux, 2003). Mutants have been
obtained, the roots of which have gene markers for indi-
vidual tissues, but they are not expressed in a small
group of apical cells of the meristem (quiescent center),
which consists of stem cells (van den Berg
Here, we analyze the problem of stem cells in
plants, which has been extensively studied in animals
with respect to their possible use for radical therapy of
previously incurable diseases. Although there are com-
mon principles in the regulation of behavior of the stem
cells in plants and animals, one cannot help seeing sig-
niﬁcant principal differences in the organization of
growth and cell proliferation between plants and animals.
It would be advisable to consider them brieﬂy and then
return to the discussion of the problem of speciﬁcity of
stem cells in plants. This paper does not contain a sufﬁ-
ciently full review of literature because of its volume.
SPECIFIC FEATURES OF ORGANIZATION
OF CELL PROLIFERATION, GROWTH,
AND MORPHOGENESIS IN PLANTS
The plant grows during its entire life and forms new
shoots, roots, and leaves. If in animals, at least in verte-
brates, the proliferation is mostly related to the substi-
tution of dead cells, physiological regeneration, in
The Problem of Stem Cells in Plants
V. B. Ivanov
Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya ul. 35, Moscow, 127276 Russia
Received January 15, 2003
—The uppermost cells of the root and shoot apical meristems are considered as stem cells. They are
similar, in many features, to the stem cells of animals. But, unlike animals, the stem cells can repeatedly arise
in plants during morphogenesis and regeneration or in tissue culture from actively dividing or differentiated
cells. When the stem cells are removed, they can be repeatedly restored from the actively dividing cells. The
maintenance of the population of stem cells is determined by interaction between the stem cells and actively
dividing cells located below according to the feedback principle. The protein synthesized in the stem cells deter-
mines how the lower located cells affect the stem cells. Speciﬁcity of stem cell identiﬁcation in plants is dis-
: stem cells, apical meristems, cell interactions, mutants, kinases.