ISSN 1021-4437, Russian Journal of Plant Physiology, 2018, Vol. 65, No. 3, pp. 319–332. © Pleiades Publishing, Ltd., 2018.
Original Russian Text © O.G. Smirnova, V.K. Shumny, A.V. Kochetov, 2018, published in Fiziologiya Rastenii, 2018, Vol. 65, No. 3, pp. 181–195.
Gene Network and Database for Genes of Wheat’s Resistance
to Pathogenic Fungi
O. G. Smirnova*, V. K. Shumny, and A. V. Kochetov
Federal Research Center, Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences,
Novosibirsk, 630090 Russia
Received April 5, 2017
Abstract⎯An overview describing a gene network that controls the formation of plant responses to diseases
caused by pathogenic fungi (http://wwwmgs.bionet.nsc.ru/mgs/gnw/genenet//viewer/Plant%20fun-
gus%20pathogen.html) is presented. The gene network represents the coordinated interactions of genes, pro-
teins, and regulatory molecules, including integrated defense mechanisms that prevent the development of
infection, localize the lesion, and minimize damage. The gene network was reconstructed on the basis of lit-
erature data, and the elements of the gene network were associated with the records of the PGR database
(Pathogenesis-Related Genes, http://srs6.bionet.nsc.ru/srs6bin/cgi-bin/wgetz?-page+top+-newId), where
information on plant genes resistant to pathogenic fungi is accumulated. Reconstruction of the gene network
allows us to formalize, visualize, and systematize possible mechanisms for the response of plant cells to fungal
infection, which may be useful for the planning of experiments and interpretation of experimental data in this
field of science.
Keywords: Triticum aestivum, pathogenic fungi, immunity, resistance genes, gene network, database
Plants are constantly exposed to a massive amount
of pathogenic fungi, some of which are able to over-
come protective barriers and cause various diseases.
Diseases caused by pathogenic fungi lead to signifi-
cant crop losses in wheat (Triticum aestivum L.).
Necrotrophs, such as Stagonospora nodorum and
Pyrenophora tritici-repentis, feed on dead tissues and
cause a 20–70% reduction in wheat yields .
Biotrophs that cause brown/leaf rust (Puccinia
triticina), yellow/striped rust (Puccinia striiformis f. sp.
tritici, Pst), stem rust (Puccinia graminis f. sp. tritici),
and powdery mildew (Blumeria graminis f. sp. tritici,
Bgt) parasitize on living tissues, which also leads to sig-
nificant yield losses. Mechanisms of protection
against rust, spotting, and powdery mildew remain
poorly understood. It is known that infection with a
pathogen causes a change in the patterns of transcrip-
tion of many genes involved in the formation of a
defense response. Defending themselves against the
attack of pathogens, plants developed multilevel pro-
tection mechanisms. The resistance of plants to
pathogens is based on a complex network of constitu-
tive and induced protective systems, in the formation
of which the products of a large number of genes take
There are two different groups of genes that provide
resistance to biotrophic pathogens. These are classic
R (resistant) genes that provide complete but race-
specific resistance in the seedling stage and QR (quan-
titative resistant) genes that give partial stability. The
products of R genes specifically recognize the corre-
sponding avirulent pathogen effectors, which lead to
the inclusion of protective reactions, including a
hypersensitivity response—rapid cell death at the site
of the pathogen entry . Unlike R genes, QR genes do
not destroy the infection but slow the progression of
the disease and provide nonspecific resistance to a
wide range of pathogens. The quantitative effect of QR
genes and their preferential action on the adult stage of
plant development make it difficult to work with them.
As a result, the largest number of studies concerns
R genes. However, varieties obtained exclusively with
the use of effective alleles of R genes are highly suscep-
tible to the appearance of highly virulent pathogens.
A high level of resistance may ensure the joint use of
QR and R genes for a long period .
During the inoculation of the pathogen, the
expression of a huge number of genes changes in the
Abbreviations: Bgt—Blumeria graminis f. sp. tritici; CC—coiled-
coil; NB-LRR—nucleotide-binding leucine-rich repeat;
PCD—programmed cell death; PR—pathogenesis-related;
Pst—Puccinia striiformis f. sp. tritici; QR—quantitative resis-
tance; R—resistance; RLK—receptor-like kinase; RLP—recep-
tor-like protein; ROS—reactive oxygen species.