Natural rubber (NR) remains an indispensable raw material with unique properties that is used in the manufacture of a large number of products and the global demand for it is growing every year. The only industrially important source of NR is the tropical tree Hevea brasiliensis (Willd. ex A.Juss.) Müll.Arg., thus alternative sources of rubber are required. For the temperate zone, the most suitable source of high quality rubber is the Russian (Kazakh) dandelion Taraxacum kok-saghyz L.E. Rodin (TKS). An obstacle to the widespread industrial cultivation of TKS is its high heterozygosity, poor growth energy, and low competitiveness in the field, as well as inbreeding depression. Rapid cultivation of TKS requires the use of modern technologies of marker-assisted and genomic selection, as well as approaches of genetic engineering and genome editing. This review is devoted to describing the progress in the field of molecular genetics, genomics, and genetic engineering of TKS. Sequencing and annotation of the entire TKS genome made it possible to identify a large number of SNPs, which were subsequently used in genotyping. To date, a total of 90 functional genes have been identified that control the rubber synthesis pathway in TKS. The most important of these proteins are part of the rubber transferase complex and are encoded by eight genes for cis-prenyltransferases (TkCPT), two genes for cis-prenyltransferase-like proteins (TkCPTL), one gene for rubber elongation factor (TkREF), and nine genes for small rubber particle proteins (TkSRPP). In TKS, genes for enzymes of inulin metabolism have also been identified and genome-wide studies of other gene families are also underway. Comparative transcriptomic and proteomic studies of TKS lines with different accumulations of NR are also being carried out, which help to identify genes and proteins involved in the synthesis, regulation, and accumulation of this natural polymer. A number of authors already use the knowledge gained in the genetic engineering of TKS and the main goal of these works is the rapid transformation of the TKS into an economically viable rubber crop. There are no great successes in this area so far, therefore work on genetic transformation and genome editing of TKS should be continued, considering the recent results of genome-wide studies.

Background: Expansins are non-enzymatic proteins involved in the softening of cell walls, the mechanism of action of which is associated with the weakening and breaking of hydrogen bonds between xyloglucans and cellulose microfibrils and is aimed at ensuring cell expansion. The aim of our work was to obtain hairy roots of tobacco with constitutive expression of the NtEXPA5 expansin gene, their morphometric analysis and assessment of the state of their antioxidant system in response to stress factors. Materials and methods: The hairy roots were obtained from transgenic tobacco plants expressing the NtEXPA5 gene under the control of the 35S promoter. Results: Constitutive expression of the NtEXPA5 gene promoted an increase in the length and dry weight of hairy roots both under normal conditions and under the action of salinity, copper sulfate, cadmium acetate, and mannitol. Both under normal conditions and under the action of stress factors in transgenic hairy roots, an increase in the activity of superoxide dismutase and the total antioxidate activity was recorded. Conclusion: Expansins exert their positive effect on the productivity and stress tolerance of plants not only through their influence on cell expansion, but also through the effect on the antioxidant system.

Brassica oleracea var. gongylodes (kohlrabi) is an economically important vegetable with edible stems. Due to the complicated in vitro regeneration, biotechnological cultivars with useful traits do not yet exist. This plant have never been subjected to genetic transformation of any kind. Therefore, the development of appropriate methods is an important task of modern plant science. A genetic construct targeting BoCPC gene have been introduced to Agrobacterium tumefaciens strain Agl0 in order to produce knockout mutants of kohlrabi. Addition of AgNO3 to the culture medium allowed to reduce browning after inoculation. Three glufosinate-resistant, PCR-positive transformants were obtained from cultivar Vienna White. In two of them expression level of target gene was significantly reduced. The described protocol allows for genetic transformation and genome editing of kohlrabi. This research opens up prospects for generation of new cultivars with improved agricultural traits such as stress tolerance, increased yields and altered metabolite content. According to the results of various studies, Vienna White can be used as a model cultivar of kohlrabi.

Red amaranth Amaranthus cruentus L. is a valuable fodder and grain crop. To generate new varieties of this plant, genetic transformation methods can be used, but for A. cruentus such methods remain undeveloped. The present study describes the results of our research in Agrobacteriummediated transformation of epicotyl segments of A. cruentus variety "Bagryanyi" by the ARGOS-LIKE transgene of Arabidopsis thaliana controlled by the 35S promoter in the binary vector pCambia 1301 with a selective hygromycin B resistance gene. For shoot regeneration from epicotyl segments after Agrobacterium-mediated transformation, Murashige-Skoog (MS) medium containing 13 μM 6-benzylaminopurine and 1 μM 1-naphthylacetic acid was used. For the selection of transgenic shoots, 10 mg/L of hygromycin B was added to the MS medium. Rooting of shoots was performed on selective MS medium supplemented with 2 μM 3-indoleacetic acid. Three transgenic amaranth plants with the genetic engineering structure 35S::ARGOS-LIKE were generated. The efficiency of Agrobacteriummediated transformation of A. cruentus was 4%. The amaranth plants transgenicity was confirmed by the PCR analysis for the presence of marker and target genes. Two transgenic plants were acclimatized to soil and open air conditions.

No abstract