1021-4437/02/4903- $27.00 © 2002
Russian Journal of Plant Physiology, Vol. 49, No. 3, 2002, pp. 364–368. Translated from Fiziologiya Rastenii, Vol. 49, No. 3, 2002, pp. 407–411.
Original Russian Text Copyright © 2002 by Goldenkova, Musiychuk, Abdeev, Berdichivets, Alizadeh, Piruzian.
-Glucanases are hydrolytic enzymes, which are
involved in depolymerization of
canases exhibit endo-
-1,3-glucanase and endo-
1,4-glucanase activities. They belong to the branched
family of structurally related proteins .
glucanases occur only in monocots, whereas
canases are common in both mono- and dicots.
canases are involved in diverse physiological pro-
cesses, such as seed germination , growth of hypoco-
tyls and coleoptiles , control of the phloem transport
and callose mobilization , and fruit maturation .
In some plant species, tobacco in particular,
glucanases are well characterized. The members of this
enzyme family are synthesized in various plant tissues.
Their synthesis is under hormonal control and is
induced by various stress factors and chemical
-1,3-glucanases comprise acidic and basic
isoforms. In healthy tissues, the concentration of acidic
-1,3-glucanases is low; pathogens, salicylic acid, and
cytokinin induce their synthesis . The enzymes are
secreted into the intercellular space, where they are
believed to destroy the hyphae of pathogenic fungi .
The expression of acidic
-1,3-glucanases was detected
during early somatic embryogenesis . The synthesis
-1,3-glucanases is induced by infection, sali-
cylic acid, and ethylene . Their genes are expressed
constitutively in healthy plants as well. The level of
their expression increases from the plant top to its base
with the highest activity in the roots . These
enzymes are synthesized in roots and ﬂowers and can
provide for constitutive resistance to pathogens .
The expression of
-1,3-glucanases is induced during
meiotic degradation of tetrads, when these enzymes
depolymerize callose .
-1,3; 1,4-glucanases are likely involved in the
metabolism of the cell wall, hydrolyzing
cans, which are the principal components of the cell-
wall hemicellulolytic structures in some monocots, and
also in the processes of seed germination . This
enzyme hydrolyzes the cell-wall
thus providing the accessibility of storage compounds
in the endosperm to other hydrolases .
Several versions of
-glucanase involvement in
plant life are proposed. One suggestion is a release of
elicitors (oligosaccharins) due to plant cell-wall degra-
-glucanases [14, 15].
Despite abundant experimental material, the role
and molecular mechanisms of
in plants remain obscure. Investigations of the
nase role in plant growth and development are also
hampered by the presence of several enzyme isoforms
differing in their intracellular localization and capacity
for induction .
We suggested that the expression of bacterial genes
(encoding enzymes with activity similar to plant
enzymes) in plants could mimic the action of plant pro-
teins, and this permits us to simulate particular meta-
The Morphogenetic Potential of Transgenic Tobacco Plants
Expressing Genes of Bacterial Glucanases
with Distinct Substrate Specificity
I. V. Goldenkova*, K. A. Musiychuk*, R. M. Abdeev*, L. G. Berdichivets**,
H. Alizadeh*, and E. S. Piruzian
* Vavilov Institute of General Genetics, Russian Academy of Sciences, ul. Gubkina 3, Moscow, 117809 Russia;
fax: 7 (095) 132-8962; e-mail: firstname.lastname@example.org
** Central Botanical Garden, National Academy of Sciences of Belarus, Minsk
Received April 28, 2001
—The expression of the bacterial gene for thermostable
-1,3-glucanase in transgenic tobacco plants
was shown to induce substantial changes in plant morphogenetic potential, whereas the expression of
1,4-glucanase did not affect essentially plant morphogenesis. Our results permit the suggestion that the expres-
sion of bacterial
-1,3-glucanase in plants elevated the level of endogenous auxin.
Key words: transgenic plants - bacterial glucanases -
-1,3; 1,4-glucanase - thermostable
enzymes - morphogenetic potential
Abbreviations and designations
: BA—benzyladenine; 35S
CaMV promoter—the promoter of 35S RNA of cauliﬂower
mosaic virus; MS—Murashige and Skoog nutrient medium.