Tea has historically been one of the most popular beverages, and it is currently an economically significant crop cultivated in over 50 countries. The Northwestern Caucasus is one of the northernmost regions for industrial tea cultivation worldwide. The domestication of the tea plant in this region took approximately 150 years, during which plantations spreading from the Ozurgeti region in northern Georgia to the southern city of Maykop in Russia. Consequently, tea plantations in the Northern Caucasus can serve as a source of unique genotypes with exceptional cold tolerance. Tea plants are known to be recalcitrant to Agrobacterium-mediated transfection. Research into optimal transfection and regeneration methodologies, as well as the identification of tea varieties with enhanced transformation efficiency, is an advanced strategy for improving tea plant culture. The aim of this study was to search for the optimal Agrobacterium tumefaciens-mediated transfection protocol for the Kolkhida tea variety. As a result of optimizing the transfection medium with potassium phosphate buffer at the stages of pre-inoculation, inoculation and co-cultivation, the restoration of normal morphology and improvement in the attachment of Agrobacterium cells to the surface of tea explants were observed by scanning electron microscopy. And an effective method of high-efficiency Agrobacteria tumefaciens-mediated transfection of the best local tea cultivar, Kolkhida, was demonstrated for the first time.

Genome modification of legumes, peas in particular, is accompanied by significant challenges. Establishing a reliable reporter system to identify tissue that expresses foreign DNA may help to optimize and develop transformation protocols for these species. The RUBY system, based on the synthesis of red betalain from tyrosine, offers a convenient solution for monitoring the efficiency of transgene introduction. To evaluate the effectiveness of RUBY application in pea tissue culture, we combined agrobacterial transformation with an in vitro cultivation system, inducing callus development. Transformed explants demonstrated RUBY pigmentation, but it disappeared during cultivation. We hypothesized that this issue is caused by tyrosine depletion. To check this suggestion, we tested whether tyrosine supplementation could maintain RUBY coloring. In the later stages, pigmentation still could not be preserved. However, our modified conditions increased the percent of colored shoot apex explants during the early cultivation stages. Thus, it is likely that some explants transformed with the RUBY cassette do not synthesize a sufficient amount of betalain due to the deficit of endogenous tyrosine. In this case, adding exogenous tyrosine would enhance betalain production and improve the detectability of tissues containing the RUBY cassette. These data can be used for the optimization of RUBY application conditions for peas and other species.

Pea (Pisum sativum) is an important agricultural crop and a model object in various fields of plant research. At the same time, the genetic modification of pea is still a difficult task, which, apparently, is associated with its low ability to regenerate. There are a lot of different pea transformation protocols, however, for most of them, the transformation efficiency, i.e. the number of transgenic plants per explant, is extremely low. In addition, none of the protocols known to us has demonstrated itself to be universal, i.e. suitable for all varieties and lines of peas. We searched for studies on the transformation and regeneration of peas and systematized the data obtained. The resulting database made it possible to identify the most effective protocols for the transformation and regeneration ofP. sativum, as well as to analyze statistically the general features of the methods used, such as the source of the explant, the composition of the culture media, the duration of cultivation, and so on. We assume that our system for the analysis of publications devoted toin vitrocell cultures can also be used for similar data on other plant species. This research was supported by the Sirius University of Science and Technology project: PBB-RND-2243.

The development of legume-rhizobium symbiosis is based on signal exchange between partners, which leads to the formation of nitrogen-fixing root nodules. Under the influence of rhizobial signal molecules, the Nod factors, the signal transduction cascade is activated, where the LysM-type receptor kinases and a complex of intracellular regulators, a significant part of which are still unknown, can play an important role. Using transcriptomic and proteomic analysis, we searched for new regulators of the signal pathway in pea Pisum sativum L., which are activated under the influence of Nod factors. Phospholipases C and D, GTPases, calcium-dependent protein kinases, and mitogen-activated protein kinases (MAPKs) have been identified among such novel regulators. The influence of one of such regulators, the MAPK6, on the development of symbiosis was studied in more detail. Using genetic engineering approaches, we increased the transcriptional activity of MAPK6 in transgenic roots, which led to an increase in the number of nodules and the biomass of pea plants. A similar effect was also found for the homologous MAPK6 gene in another legume Medicago truncatula, which has a type of nodulation similar to that one in pea. New approaches have been developed to obtain stable pea transformants with enhanced level of MAPK6 transcription using the constitutive p35S promoter. A comprehensive study of such plants inoculated with rhizobia was carried out. In addition, the approaches for genome editing of pea plants have been designed using the CRISPR/Cas system, when the MAPK6 gene was used as a target. Thus, the possibility of using genetic engineering methods to obtain plants with increased symbiosis efficiency was investigated.

Pisum sativum L. (pea) is one of the most important agricultural crops, because its seeds have high protein content, and, due to its ability have symbiotic relationships with nitrogen-fixing bacteria, these plants need less fertilizers. Nevertheless, we are faced with the need to improve old and create new methods for obtaining novel varieties of peas and other agricultural plants. The formation of regenerated pea plants is difficult to achieve in the in vitro culture. Accordingly, transformation of this species is a laborious process. In this regard, the search for morphogenic regulators of somatic embryogenesis (SE) in pea is an urgent problem. A number of publications reported on the genes regulating the SE process in a model plant from the legume family, Medicago truncatula [1]. In our study, we search for the in vitro cultivation system in peas, suitable to test the effect of putative SE regulators in this species. We tested several pea transformation techniques using different explant variants: embryonic axes from mature and immature seeds, as well as shoot apexes. Out of the tested options, the transformation of mature seeds turned out to be optimal. We also designed a set of DNA constructs in silico, which are suitable for the search of morphogenic regulators in peas.