In late December 2019, the first cases of COVID-19 emerged as an outbreak in Wuhan, China that later spread vastly around the world, evolving into a pandemic and one of the worst global health crises in modern history. The causative agent was identified as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although several vaccines were authorized for emergency use, constantly emerging new viral mutants and limited treatment options for COVID-19 drastically highlighted the need for developing an efficient treatment for this disease. One of the most important viral components to target for this purpose is the main protease of the coronavirus (Mpro). This enzyme is an excellent target for a potential drug, as it is essential for viral replication and has no closely related homologues in humans, making its inhibitors unlikely to be toxic. Our review describes a variety of approaches that could be applied in search of potential inhibitors among plant-derived compounds, including virtual in silico screening (a data-driven approach), which could be structure-based or fragment-guided, the classical approach of high-throughput screening, and antiviral activity cell-based assays. We will focus on several classes of compounds reported to be potential inhibitors of Mpro, including phenols and polyphenols, alkaloids, and terpenoids.

The genus Vaccinium includes almost 500 species, among which there are economically important species of cranberries V. macrocarpon Ait. and V. oxycoccos L., lingonberries V. vitis-idaea L., bilberries V. myrtillus L. and blueberries V. uliginosum L., V. angustifolium Ait., V. corymbosum L., V. virgatum Ait. Despite the fact that many of these species were actively used by humans in medicine and food, their active selection began in the 20th century, in connection with which a classification of the genus according to morphological characters was developed. Many of these data remain relevant to the present day. The development of the ideas of molecular phylogeny prompted a revision of the old classification, identifying a number of difficulties that do not allow one to unambiguously determine phylogenetic relationships within the genus. Today, the genus includes 33 sections, while the species composition of the sections and the evolutionary relationships between them remain controversial. This review discusses various approaches to the study of the structure of the genus Vaccinium: from classical to phylogenomic, the main results of using these approaches and their prospects.

Agrobacterium mediated transformation is one of the most studied examples of horizontal gene transfer between pro- and eukaryotes. During this process a part of the Ti-plasmid T-DNA is transferred into the plant cell genome. These sequences could be preserved in the genomes during evolution and inherited in a series of sexual generations. Such plants are described within the genus Vaccinium L. [1]. Our research team is currently analyzing natural transgenes in V. oxycoccos L., V. japonicum Miq., V. conchophyllum Rehder, V. emarginatum Hayata, V. myrtilloides Michx., V. virgatum Ait., V. corymbosum L., V. darrowii Camp, V. smallii A. Gray, V. praestans Lamb., V. ovalifolium Sm., V. myrtillus L., V. uliginosum L., V. vitis-idaea L. Previously, analyzing the natural transgenes in another genus (Camellia L.) [2], we showed the importance of reconstructing the allelic states of transgenes for phylogenetic studies. In this paper, we present a comprehensive approach for studying the allelic state of the rolB/C-like gene in plants of the genus Vaccinium. It combines molecular genetic and bioinformatic research methods. Molecular genetic methods involve Sanger sequencing of a gene sequence in a large number of samples, while for each sample the sequence is presented as a set of polymorphic positions in binary form. Allele resolution occurs based on the description of alleles in homozygotes and a series of subtractions of known alleles in heterozygous samples. The second method involves the analysis of SRA (Sequence Read Archive) sequences available in the databases. SRA is a repository of high-throughput sequencing raw data. Based on our work, we can conclude that both of these approaches make it possible to describe the allelic state of the rolB/C-like gene in representatives of the genus Vaccinium. The work was performed using the equipment of the Resource Center of Saint Petersburg State University Development of Molecular and Cellular Technologies with the support of the Ministry of Science and Higher Education of the Russian Federation in accordance with agreement No. 075-15-2022-322 dated 04/22/2022 on the provision of a grant in the form of a subsidy from the Federal budget of the Russian Federation. The grant was provided as part of the state support for the creation and development of the world-class Scientific Center Agrotechnologies for the Future.

A variety of plant species found in nature contain agrobacterial T-DNAs in their genomes which they transmit in a series of sexual generations. Such T-DNAs are called cellular T-DNAs (cT-DNAs). cT-DNAs have been discovered in dozens of plant genera, and are suggested to be used in phylogenetic studies, since they are well-defined and unrelated to other plant sequences. Their integration into a particular chromosomal site indicates a founder event and a clear start of a new clade. cT-DNA inserts do not disseminate in the genome after insertion. They can be large and old enough to generate a range of variants, thereby allowing the construction of detailed trees. Unusual cT-DNAs (containing the rolB/C-like gene) were found in our previous study in the genome data of two Vaccinium L. species. Here, we present a deeper study of these sequences in Vaccinium L. Molecular-genetic and bioinformatics methods were applied for sequencing, assembly, and analysis of the rolB/C-like gene. The rolB/C-like gene was discovered in 26 new Vaccinium species and Agapetes serpens (Wight) Sleumer. Most samples were found to contain full-size genes. It allowed us to develop approaches for the phasing of cT-DNA alleles and reconstruct a Vaccinium phylogenetic relationship. Intra- and interspecific polymorphism found in cT-DNA makes it possible to use it for phylogenetic and phylogeographic studies of the Vaccinium genus.