ISSN 1022-7954, Russian Journal of Genetics, 2007, Vol. 43, No. 1, pp. 1–11. © Pleiades Publishing, Inc., 2007.
Original Russian Text © E.V. Deineko, A.A. Zagorskaya, V.K. Shumny, 2007, published in Genetika, 2007, Vol. 43, No. 1, pp. 5–17.
The technologies of production of transgenic plants
are based on transferring genes from different heterol-
ogous systems (viruses, microorganisms, animals, and
humans), integrated into genetic constructs by means of
genetic engineering methods, into the plant genome.
The range of practical application of genetically modi-
ﬁed plants is rather broad, ranging from improvement
of commercial traits in valuable crop cultures  to
phytoremediation of environmental pollution [2–4].
They can also be utilized as “bioreactors” for accumu-
lating biologically active substances and proteins
employed in medicine [5, 6].
To date, two approached have been developed to
transport foreign genes in the form of exogenous DNA
fragments into plants. One of these methods involves
on direct transfer of exogenous DNA into plant cells
(direct transformation). The other is based on the natu-
ral ability of soil bacteria
to infest plant tissues, transferring
into the plant genome their own genes, whose products
are required for colonizing the plants tissue by the bac-
teria. Upon integration into functionally active regions
of the plant genome, the fragments of bacterial DNA
(T-DNA) can change the functioning of the plant genes.
The ﬁrst mutations induced by means of T-DNA
insertion into the plant genome were generated in
by a research team headed by Feld-
mann . To date, this collection of T-DNA-induced
mutations is the largest [8, 9].
The spectrum of T-DNA-induced mutations
reported in literature is rather broad. Mutations have
been described involving individual morphological
traits (plant height [7, 10, 11], size and shape of leaf
blades [12, 13], ﬂower structure [14–16]) and forma-
tion of male and female gametophytes, resulting in low
fertility [17–23] and impairing embryo development at
early stages [24–28], and mutations providing resistance
to agrobacterial infection of the transformants [29–33].
Note that the great majority of T-DNA mutations was
revealed among transgenic
ment of simple procedures of
transformation using germinating seeds  and gener-
ative shoots [35, 36] in this species signiﬁcantly
increased the yield of transgenic plants, which increased
the probability of selection of transformants with various
alterations in the expression of different traits.
Note that mutations induced by radiation or chemi-
cal agents can result in either small alterations (substi-
tution of several nucleotides) or to large chromosome
rearrangements. The integrity of gene structure may
also be disturbed by insertion of exogenous DNA upon
agrobactarial infection of plant tissues. Thus,
-induced transformation may be regarded as a
novel source of generating various mutations. For
mutations causing defective
chlorophyll synthesis are alleles of the same gene local-
ized in the same chromosome 4 locus . One of
, was induced by T-DNA insertion; the other,
, by a chemical mutagen.
The important advantage of mutations induced by
insertion of exogenous DNA fragments is the fact that
the insertion may serve as marker of genomic localiza-
tion of genes whose functioning was disturbed. Such
tagging is problematic in analysis of spontaneous muta-
tions and mutations induced by radiation and chemical
mutagens. Thus, modiﬁcation of the plant genome by
means of genetic engineering techniques can impart
new properties to the plants as well as employ them for
studying the structure and mechanisms of functioning
of the plant genome.
In this review, we have attempted to collect and sys-
tematize the extensive experimental data on the
changes occurring in the plant genome upon integration
of exogenous DNA. We focused on mutations in dicot-
yledonous plant generated by a natural insertion agent,
the T-region of the
Ti plasmid. Muta-
tions generated by insertion of exogenous DNA frag-
ment through direct transfer are not considered.
T-DNA-Induced Mutations in Transgenic Plants
E. V. Deineko, A. A. Zagorskaya, and V. K. Shumny
Institute of Cytology and Genetics, Russian Academy of Sciences, Novosibirsk, 630090 Russia;
fax: (383) 333-12-78; e-mail: email@example.com
Received February 15, 2006
—The review surveys experimental data on changes of individual traits in genetically modiﬁed (trans-
genic) plants. The attention is focused on mutations induced by T-DNA insertions upon
transformation of dicotyledonous plants. The character of mutation appearance in transgenic plants is exam-
ined. The prospects of mutations induced by T-DNA insertions are considered.