Winter wheat is considered to have a more developed root system compared to spring one. A few studies showed a dependence of root system architecture from the allelic state of Vrn-1 locus. The aim of this work was to obtain spring wheat plants with a large root system. To achieve this, we used a hybrid population derived from crossing a spring variety Saratovskaya 29 (S29) with small roots and a winter introgression line IL 5D-5 with large roots. By a direct selection for spring habit and large root system, such plants were obtained in F5 generation. The spring habit of the plants was determined by dominant alleles Vrn-A1a and Vrn-B1c inherited from S29. They did not inhibit root development. The overall root system phenotype was similar to that of the winter line IL 5D-5. We suppose that a gene with a dominant mode of inheritance controlling large roots is located near vrn-D1. It was obtained from the introgression region of 5D chromosome from Ae. tauschii, present in the IL 5D-5 line. The F5 plants were studied for flowering date, root length, root weight, technological properties of grain, and productivity components. They substantially exceeded the spring parent for root length and weight, protein and gluten content in grain, stem length, shoot number, grain number and weight from the plant and 1000-grain weight. Root length correlated with stem length and 1000-grain weight, root weight correlated with flour particle diameter.

Roots are an integral part of the plant organism. This is the main organ that records the soil water status and transmits signals to the shoot. The architecture of the root system determines strong rooting of the plant and effective absorption of nutrients and water from the soil. In wheat (Triticum aestivum L., genomic formula AABBDD), the genes that determine the parameters of the root system are still unknown. It was shown that synthetic wheats obtained using the species Aegilops tauschii Coss. have a large root system. The single chromosome substitution line of Chinese Spring (CS) variety, carrying 5D chromosome from a synthetic wheat has a large root system. On its basis, recombinant (introgressed) lines were obtained that carry fragments of chromosome 5D of Ae. tauschii and have a large length and weight of roots (see Fig. 1 and Table 1). The breeding goal of our studies was to transfer this valuable trait to the spring variety Saratovskaya 29 (S29) with a small root system. In the course of successive selections form hybrids between S29 and IL 5D-5 line, early maturing families with a large root system were obtained. Their average root length was 1.4 times higher than that of S29, and their weight was more than three times greater (see Table 2). At the same time, the lines showed a grain weight per plant two to five times greater than that of S29 while maintaining the thousand-grain weight at the level of the parent variety. Most of the lines inherited a high protein and gluten content in grain. The presence of such a gene in this region of introgression in chromosome 5D was predicted earlier. One of the lines, along with a powerful root system and high gluten content, demonstrated excellent physical properties of flour and dough and may be classified as a strong wheat. The article contains 1 Figure, 2 Tables, 6 References. The Authors declare no conflict of interest.

Resistance to pre-harvest sprouting (PHS) is an agronomically important trait affecting the yield and grain quality of bread wheat. PHS resistance depends both on environmental factors and the genotypic and phenotypic properties of wheat varieties. It is known that wheat varieties with red-grain are more resistant to PHS than white-grain varieties. However, at present there are no methodological approaches that allow to unambiguously distinguish red-grain varieties according to the level of PHS resistance. The purpose of the study was to compare different methods for efficient differentiation of soft winter wheat (Triticum aestivum L.) varieties for resistance to PHS. The germination index (GI), α-amylase activity (AAA), a digital grade of the grain color and genetic bases of the wheat varieties the grain was determined in 164 winter wheat, among them 156 were red-grain. The studies were carried out at the late milk/hard dough (LM/HD; GS77-GS87) stage and the hard grain (HG; GS92-GS93) stage. Based on the dynamics of GI it was found that late LM/HD stage is the most suitable for GI evaluation. AAA was performed using the Ceralpha method and falling number (FN) evaluation. An increase in the level of AAA during grain ripening of wheat varieties was shown. A negative correlation was found between GI and FN, FN and AAA. Using the Lab color model to assess the color variation of the grain coat allow to identify 3 variants of grain color. Genetic base of wheat varieties was analyzed by means of allelic composition of the Tamyb10 gene, which participate in the formation of the red color of grain. The results indicated that digital analysis and allelic composition of the Tamyb10 cannot be used as additional criterion for separation of red-grain wheat varieties for resistance to PHS. This is despite the fact that the numerous group of the varieties contain two or more dominant Tamyb10 gene. In general, a comparison of varieties by all three parameters allow to identify a group of varieties that are most PHS resistant. This group consist of 73 red-grain varieties out of 156, while no white-grain PHS-resistant varieties were identified.

Устойчивость к прорастанию зерна на корню (ПЗНК) является хозяйственно важным признаком, который влияет на качество зерна и урожайность пшеницы. Данная устойчивость зависит как от факторов окружающей среды, так и от генотипических и фенотипических особенностей сортов пшеницы. Известно, что краснозерные сорта пшеницы являются более устойчивыми к ПЗНК, чем белозерные. Однако в настоящее время не существует подходов, позволяющих однозначно различать краснозерные сорта пшеницы по степени устойчивости к ПЗНК. Целью настоящей работы являлось сравнение различных подходов для эффективной дифференцировки сортов озимой мягкой пшеницы (Triticum aestivum L.) по устойчивости к ПЗНК. У 164 сортов озимой мягкой пшеницы, среди которых 156 были краснозерными, были определены индекс прорастания (ИП), активность α-амилазы (ААА), проведена цифровая и генетическая оценка уровня красной окраски зерновки. Исследования проводили на стадиях молочно-восковой спелости (М/ВС) и полного созревания (ПС) зерна. Исходя из динамики изменения ИП на стадиях М/ВС и ПС зерна установлено, что наиболее целесообразно проводить оценку ИП на стадии М/ВС зерна. Анализ ААА был проведен с использованием метода Церальфа и определения числа падения (ЧП). Показано повышение уровня ААА в процессе созревания зерна у изученных сортов. Была выявлена отрицательная корреляционная связь между ИП и ЧП, ЧП и ААА. Использование цветовой модели Lab для оценки окраски оболочки зерна позволило выделить 3 типа окраски зерна. Изучены аллельные варианты гена Tamyb10, контролирующего красную окраску зерна. Анализ цифровой оценки окраски зерна и аллельного состава генов Tamyb10 не выявил дополнительного к ИП и ЧП критерия, который можно было бы использовать для разделения краснозерных сортов пшеницы по устойчивости к ПЗНК. В то же время показано, что наиболее многочисленная группа из изученных сортов, имеет от двух и более доминантных генов, контролирующих красную окраску зерна. В целом, сравнение краснозерных сортов по всем трем параметрам позволило выделить группу сортов, наиболее устойчивых к ПЗНК. В эту группу вошли 73 краснозерных сорта мягкой пшеницы из 156 изученных, при этом белозерных сортов, устойчивых к ПЗНК, выявлено не было.

One of the main ways to fine-tune the adaptive potential of wheat cultivars is to regulate the timing of flowering using the genes of the Vrn-1 locus, which determines the type and rate of development. Recently, with the use of introgression and isogenic lines of bread wheat, it was shown that this locus is involved in the genetic control of root length and weight both under irrigation and drought conditions. It turned out that the VrnA1 gene is associated with a significant decrease in the size of the root system in a winter genotype. The Vrn-A1 gene had the strongest effect on the reduction of the root system in comparison with the homoeoallelic genes Vrn-B1 and Vrn-D1. The aim of this work was to determine whether the allelic composition of the genes at the Vrn-1 locus affects the root size in seven spring cultivars and in two lines of bread wheat differing in flowering time under conditions of normal watering and drought. The research was carried out in a hydroponic greenhouse; drought was created at the tillering stage. In this work, we have shown that early flowering wheat cultivars with the dominant Vrn-A1а allele have more lightweight and shorter roots under normal watering conditions compared to the late flowering carriers of the dominant homoeoalleles Vrn-B1 and Vrn-D1. In drought conditions, the root length decreased insignificantly, but the weight of the roots significantly decreased in all genotypes, with the exception of Diamant 2. It has been hypothesized that the level of the transcription factor VRN-1 at the onset of drought may affect the size of the root system. The large variability in root weight may indicate the participation, in addition to the Vrn-1 locus, of other gene networks in the formation of this trait. Breeders working to develop early maturing varieties should consider the possibility of reducing the root size, especially in arid conditions. A significant increase in the root size of line 821 with introgressions into chromosomes 2A, 2B, and 5A from T. timopheevii indicates the possibility of using congeners as a source of increasing the trait in wheat.

Leaf pubescence is widespread among higher plants. In bread wheat, a relationship was found between this trait and the efficiency of photosynthetic processes and productivity. In this work, we established the chromosomal localization of the gene for leaf pubescence introgressed from Triticum timopheevii into a bread wheat line 821 and studied its expression in the genetic background of two wheat cultivars differing in genetic control and phenotypic expression of pubescence. To obtain quantitative characteristics of pubescence in cultivars and hybrid populations, the LHDetect2 program was used, which makes it possible to estimate the length and number of trichomes on a leaf fold. A genetic analysis showed the dominant inheritance of the gene. Monosomic analysis F-2 was used to establish chromosome localization and investigate the expression of the gene in cultivars Saratovskaya S29 (S29) and Diamant 2 (Dm2). As a result, the gene Hl(tt), introgressed from T. timopheevii, was identified and localized in the distal region of the long arm of 5A chromosome for the first time. In both F2 populations, the gene reduced the density of trichomes and formed long trichomes, uncharacteristic for the two recipient cultivars S29 and Dm2. A larger number of long trichomes was formed in the genetic background of S29, which carry the bread wheat gene Hl1 and Hl3 for leaf pubescence, than in Dm2. Development of substitution and isogenic lines with the fragment of introgression carrying the gene Hl(tt) will allow determining function and assessing the adaptive significance of the gene more precisely.

Understanding the genetic architecture of drought tolerance is of great importance for overcoming the negative impact of drought on wheat yield. Earlier, we discovered the critical role of chromosome 2A for the drought-tolerant status of wheat spring cultivar Saratovskaya 29. A set of 92 single-chromosome recombinant double haploid (SCRDH) lines were obtained in the genetic background of Saratovskaya 29. The lines carry fragments of chromosome 2A from the drought-sensitive cultivar Yanetzkis Probat. The SCRDH lines were used to identify regions on chromosome 2A associated with the manifestation of physiological and agronomical traits under distinct water supply, and to identify candidate genes that may be associated with adaptive gene networks in wheat. Genotyping was done with Illumina Infinium 15k wheat array using 590 SNP markers with 146 markers being polymorphic. In four identified regions of chromosome 2A, 53 out of 58 QTLs associated with physiological and agronomic traits under contrasting water supply were mapped. Thirty-nine candidate genes were identified, of which 18 were transcription factors. The region 73.8–78.1 cM included the largest number of QTLs and candidate genes. The variation in SNPs associated with agronomical and physiological traits revealed among the SCRDH lines may provide useful information for drought related marker-assisted breeding.

The properties of the root system are especially important under drought, which is currently the most significant climate threat worldwide. The aim of this work was to investigate the relationship between the root system development and vernalization requirements under contrasting irrigation conditions in bread wheat using lines with alien introgressions. A set of single chromosome substitution lines Chinese Spring (Synthetic 6x, AABBDD) and D-genome derived introgression lines were used to study the relationships. It was found that 1A substitution resulted in a substantial reduction of root length and weight while 5D substitution, on the contrary, led to a significant increase compared to the recipient and the donor under both irrigation regimes. The greatest root weight, root length, and number of days to flowering were detected in the lines carrying a common introgression fragment of the 5D chromosome connected with the molecular marker Xgwm292 and the Vrn-D1 gene. The lines with the introgression in this region had a significantly larger root length and weight compared with the recipient and donor under all conditions of irrigation. The combination of prolonged vernalization and drought negatively affected the development of roots in all lines with the most pronounced effect on root weight. With the use of monosomic analysis, it was shown that the Vrn-A1 gene has a substantial reducing effect on the root length and weight. The revealed relationship between the flowering time and root system development can be used for breeding of wheat cultivars more adapted for growing in arid conditions.

Transgenic technologies belong to important tools of reverse genetics and biotechnology in plants. Targeted genetic modifications can reveal functions of genes of interest, change metabolic and regulatory pathways, or result in accumulation of valuable proteins or metabolites. However, to be efficient in targeted genetic modification, the chimeric gene construct should be designed properly. In particular, the promoters used to control transgene expression need to be carefully chosen. Most promoters in widely used vectors belong to strong and constitutively expressed variants. However, in many cases transgene expression has to be restricted to certain tissue, stage of development, or response to some internal or external stimuli. In turn, a large variety of tissue-specific promoters have been studied and information on their characteristics may be recovered from the literature. An appropriate promoter may be selected and used in genetic construct to optimize the transgene transcription pattern. We have previously designed the TGP database (TransGene Promoters, http://wwwmgs.bionet.nsc.ru/mgs/dbases/tgp/home.html ) collecting information from the publications in this field. Here we review the wide range of noncanonical tissue-specific and developmentally regulated promoters that might be used for transgene expression control.

Genetic engineering allows for an extension beyond the limits of a species' natural variability. This enables the production of ornamental plants with novel colors and shapes of flowers, enhanced resistance, and a complex of characteristics gaining aesthetic and economic advantages. As a rule, success in achievement of desirable effects requires changes in the expression patterns of particular genes. A key regulatory element determining the level and tissue and temporal specificity in gene expression is a promoter. Therefore, an appropriate promoter must be chosen in the first place to build the planned structures of genetic constructs for transgene expression in plants. In recent years, many novel constitutive, tissue-specific, and induced promoters of plant origin have been explored. They may broaden advancements for derivation of novel forms and cultivars by means of a strictly directed expression of the transferred genes. The review discusses literary data on promoter application to biotechnology for the cases of ornamental plants.

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%20fungus%20pathogen.html ) is presented. The gene network represents the coordinated interactions of genes, proteins, 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 literature 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.

Plants are exposed to a large number of pathogenic fungi. In recent years many wheat resistance genes have been identified. However, the sequencing of the Triticum aestivum L. genome is still taking place and the nucleotide sequences of most resistance genes are not yet known. In addition, the study of allelic variants of resistance genes is important for better understanding the molecular mechanisms of their action. In this paper we present an information resource for accumulating data on sequenced genes of wheat and its relatives providing resistance against diseases caused by fungal pathogens. The database (Pathogenesis-Related Genes, PRG) contains information on genes’ chromosomal localization and functional activities, nucleotide sequences, and single nucleotide polymorphisms associated with their effects. PRG provides data on the proteins encoded, pathogens, and diseases, as well as on the resistance gene expression patterns in response to pathogen inoculations, exposure to hormones, and various external stimuli. It also has cross-references to related entries from the databases on nucleotide sequences (GenBank) and proteins (UniProt). Information is entered into the database as a result of the annotation of scientific publications and manual curation. Currently PRG compiles data on 75 allelic variants of 66 resistance genes. The PRG database was developed on the basis of the SRS (Sequence Retrieval System) platform. This system allows the use of complex queries and visualization tools and automatically generates a web interface with the information in table or text formats. PRG may be useful for researchers studying plant biology or breeding new plant cultivars resistant to fungal diseases. It is available at http://srs6.bionet.nsc.ru/srs6bin/cgi-bin/wgetz?-page+top+-newId.

Vegetable protein synthesis systems for industry, medicine, and research are becoming increasingly popular. The technology of protein production in plants has certain advantages, compared with the expression systems of bacteria and yeast. The rich variety of promoters, regulatory elements, affinity tags, and fusion partners that are used in molecular biology and plant biotechnology can create hybrid genetic constructs adapted to the solution of various tasks associated with protein synthesis and purification. New methods of modification of plant systems are being developed for the synthesis of functionally active human proteins whose structure is close to the natural analogues. This review shows current approaches to increase the yield of the target protein, facilitating the procedures of its isolation and purification and preventing degradation.

A huge variety of phytopathogens (viruses, bacteria, fungi) are potentially able to infect plant tissues and cause diseases. Numerous plant genes control a complex network of defense mechanisms based on both constitutive and inducible processes. The cell wall is a primary barrier the pathogens have to penetrate to start the infection process. However,it is able to block invasion by most non-specific potential pathogens. The cell wall structure may differ in various plant species. It is based on the net of cellulose microfibrils linked by hemicellulose molecules. Pectin and lignin are the other important cell wall constituents. Dozens of proteins inside the cell wall are involved in structural and metabolic processes as well as in signal transduction and regulatory circuits (more information is available in W allProtDB database). Each of these components contributes to resistance to pathogens. At the points of contact with potential pathogens cell wall structural changes and accumulation of metabolites with antimicrobial, antifungal or antiviral activities occur. Some pathogens could produce hydrolytic enzymes able to degrade cellulose and pectin to counteract these non-specific plant resistance mechanisms. In turn, plants developed the inhibitors of pathogen-related enzymes and this “arms race” is an important part of plant evolution and host-pathogen interaction mechanisms. Plants also can evaluate the cell wall state to compensate for imbalances and deficiencies. For instance, mutants with cellulose deficiency may have a higher lignification rate and a stronger stress response. The cell wall is also a source of signal molecules triggering the initiation of response mechanisms. In total, the plan cell wall is a complex dynamic structure able to prevent infection by most potential (non-specific) pathogens and switch on the mechanisms of plant immune response. The reconstruction of gene networks controlling the cell wall structural and functional organization during the growth, and under normal and stressful conditions is vitally important for understanding the basic molecular mechanisms of development and stress resistance. The mechanisms of specific and non- specific plant resistance to various phytopathogens connected to the cell wall structure are reviewed. The roles of the cell wall constituents in pathogen detection and the induction of defense mechanism are discussed

A huge variety of phytopathogens (viruses, bacteria, and fungi) are potentially able to infect plant tissues and cause diseases. Numerous plant genes control a complex network of defense mechanisms based on both constitutive and inducible processes. The cell wall is a primary barrier the pathogens have to penetrate to start the infection process. Resistance at the level of the cell wall can prevent invasion of most potential pathogens. The cell wall structure may differ in various plant species. It is based on the network of cellulose microfibrils linked by hemicellulose molecules. In the growing parts of the plant, this network is integrated into the matrix of pectin polysaccharides. In the formed tissues, the cell wall is reinforced with lignin. In addition to polysaccharides, the cell wall contains a significant number of proteins implementing structural and enzymatic functions. The WallProtDB database stores information on many proteins of the cell wall of different plant species. Each of the cell wall components contributes to the formation of resistance to pathogens. The sites of contact with potential pathogens are characterized by the additional strengthening of the cell wall and the accumulation of antimicrobial secondary metabolites. The pathogens secrete enzymes that can break down the components of the cell wall. In response to the attack of microbes the plant produces inhibitors of microbial hydrolytic enzymes. The plant is also able to assess the number of components of the cell wall. For instance, mutants deficient for cellulose normally have an increased level of lignification and an increased defense response. Emerging after the action of microbial enzymes, low-molecular-weight cell wall fragments perform the signal function, enhancing the protective response of the plant. Thus, the cell wall is a dynamic structure, which can prevent the invasion of the majority of potential pathogens and initiate different variants of the immune response. Reconstruction of gene networks that control the structural and functional organization of the cell wall during the growth and under biotic and abiotic stress is crucial for understanding the molecular mechanisms of development and stress resistance. The review deals with the mechanisms of specific and nonspecific resistance of plants to pathogens of different nature, which are related to the cell wall. The cell wall structure and the role of various components in the detecting the invasion of plant pathogens and the induction of defense mechanisms are discussed.

Gene networks controlling the plant resistance to different phytopathogens are rather complex; hundreds of genes can be involved in them. Infection causes considerable changes at molecular-genetic, biochemical, physiological, and morphological levels both locally (in the place of invasion) and systemically. The reconstruction of gene networks that are responsible for plant defense against pathogenic bacteria, fungi, and viruses is required for the elucidation of the underlying molecular mechanisms as well as for the development of new approaches to crop improvement. The transcriptional activity of genes involved in the defense mechanisms usually increases in response to the infection; therefore, the characteristics of their promoters is an important source of information for the detection of transcription factors that control their activity and for the search for new genes involved in the pathogen response. The data on promoters are required for the creation of plants that are resistant to phytopathogens by gene engineering techniques. The data on promoters of pathogen-sensitive genes with an experimentally verified expression pattern annotated in the TransGene Promoters (TGP) database are presented in the article. The TGP database can be used as a source of information for interpretation of transcriptome data and when planning genetically engineered experiments directed towards increasing plant resistance to pathogens of different origins.