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At all stages of flowering, a decisive role is played by the family of MADS-domain transcription factors, the combinatorial action of which is described by the ABCDE-model of flower development. The current volume of data suggests a high conservatism of ABCDE genes in angiosperms. The E-proteins SEPALLATA are the central hub of the MADS-complexes, which determine the identity of the floral organs. The only representative of the SEPALLATA3 clade in tomato Solanum lycopersicum L., SlMADS5, is involved in determining the identity of petals, stamens, and carpels; however, data on the functions of the gene are limited. The study was focused on the SlMADS5 functional characterization. Structural and phylogenetic analyses of SlMADS5 confirmed its belonging to the SEP3 clade. An in silico expression analysis revealed the absence of gene transcripts in roots, leaves, and shoot apical meristem, and their presence in flowers, fruits, and seeds at different stages of development. Two-hybrid analysis showed the ability of SlMADS5 to activate transcription of the target gene and interact with TAGL1. Transgenic plants Nicotiana tabacum L. with constitutive overexpression of SlMADS5 cDNA flowered 2.2 times later than the control; plants formed thickened leaves, 2.5–3.0 times thicker stems, 1.5–2.7 times shortened internodes, and 1.9 times fewer flowers and capsules than non-transgenic plants. The flower structure did not differ from the control; however, the corolla petals changed color from light pink to magenta. Analysis of the expression of SlMADS5 and the tobacco genes NtLFY, NtAP1, NtWUS, NtAG, NtPLE, NtSEP1, NtSEP2, and NtSEP3 in leaves and apexes of transgenic and control plants showed that SlMADS5 mRNA is present only in tissues of transgenic lines. The other genes analyzed were highly expressed in the reproductive meristem of control plants. Gene transcripts were absent or were imperceptibly present in the leaves and vegetative apex of the control, as well as in the leaves and apexes of transgenic lines. The results obtained indicate the possible involvement of SlMADS5 in the regulation of flower meristem development and the pathway of anthocyanin biosynthesis in petals.

Starch degradation in plants is mediated by amylases, the activity of which is post-translationally regulated by inhibitors. It is assumed that the SbAI amylase inhibitor activity is associated with potato cold stress resistance. The study of possible correlations of the SbAI variability with the cold resistance of potato species will improve the understanding of the starch metabolism regulation during plant development and stress response. In the present study, the genome sequences homologous to SbAI were identified in 12 potato species of section Petota. In total, 36 allelic variants of the gene and 31 variants of the protein were revealed. Comparison with data on S. tuberosum cultivars showed that the SbAI cultivar polymorphism is 1.4–1.7 times higher than the interspecific, but the species possess a larger number of allelic variants. Phylogenetic analysis revealed that, for S. demissum, S. acaule, and S. stoloniferum, each species SbAI allelic variants did not get into one clade. The SbAI gene expression pattern was determined in various organs of the species S. tuberosum (cv. Nadezhda), S. rybinii, S. chacoense, and S. kurtzianum. In leaves, S. chacoense SbAI expression level was 13, 50, and 250 times higher than in S. tuberosum, S. kurtzianum, and S. rybinii, respectively. Varied levels of SbAI expression in the species may be due to different initial contents of both synthesized starch and reducing sugars in the leaves. In tubers, S. tuberosum SbAI expression was 5.2, 8.6, and 430 times higher than in S. kurtzianum, S. chacoense, and S. rybinii. In roots, S. rybinii SbAI expression was 2.4 times higher than in S. chacoense and 42.3 times higher than in S. kurtzianum and S. tuberosum. The absence of correlation between the SbAI expression level and the species cold resistance was shown. The obtained expression data suggest that different potato species and cultivars may differently regulate tuber starch content.

Background. Plant chloroplast genome have conservative structure, but its nucleotide sequence is polymorphous due to which cpDNA fragments are often used in taxonomic and phylogenetic studies. Despite the widespread distribution and use of Fabeae species, mainly peas ( Pisum ), data on the intraspecific diversity of cpDNA fragments are almost absent. The aim of the work was to analyze the intraspecific variability of three cpDNA spacers in Pisum. Materials and methods. As a result of the work, intergenic spacers trnY – trnT , trnH – psbA and rpoB – trnC in 38 accessions of the Pisum and related Fabeae species were sequenced. Despite the fact that the selected chloroplast fragments are generally considered to be sufficiently variable in plants and are often used for phylogenetic studies, Pisum accessions have been found to have no intraspecific differences in two of the three spacers sequences analyzed. Results and conclusion. A total 97 SNPs were detected in Pisum accessions, seven of them distinguished P. sativum from P. fulvum . The most variable of the analyzed fragments was the intergenic spacer rpoB–trnC . Based on rpoB–trnC sequence 17 haplotypes in P. sativum and four haplotypes in P. fulvum were revealed. The cpDNA sequencing data were used for a phylogenetic analysis. On the obtained tree Vavilovia formosa accession formed a separate branch from pea accessions. All Pisum accessions fall in one cluster, split into distinct P. sativum and P. fulvum subclusters (BI = 99%).

Genes homologous to PSY1 and PSY2 that encode phytoene synthase isoforms in Capsicum species C. baccatum, C. chinense, C. frutescens, C. tovarii, C. eximium, and C. chacoense were identified. High conservatism of functionally significant sites of phytoene synthases of the analyzed accessions was revealed. It was found that only PSY1-based clustering of pepper species corresponds to the traditional Capsicum phylogeny; C. eximium was a part of the Purple corolla complex, and C. chacoense was equidistant from Annuum and Baccatum clades. The absence of significant differences between PSY1 and PSY2 of yellow-fruited C. chinense and red-fruited pepper accessions was shown. The yellow color of C. chinense fruit may be the result of both decreased PSY1 expression and increased PSY2 transcription. Thus, it was demonstrated that the acquired fruit pigmentation retains strict phylogenetic limitations, which, however, can be overcome using artificial selection for the activity of phytoene synthase PSY1.

New TOMATO MADS 5 (TM5) homologous genes were identified in evolutionarily recent, red-fruited and more ancient, wild green-fruited tomato species. It was shown that the identified TM5 homologs belong to the SEPALLATA3 clade; thus, the SEP subfamily diversification was characterized. For the first time, the TM5 and RIN co-expression pattern was determined in flowers, immature green fruits, and ripe fruits of Solanum lycopersicum and in five wild tomato species. It was shown that, regardless of the species, the level of TM5 transcription in flowers was higher than that of RIN, whereas in fruits it was lower than the level of RIN transcription. The data obtained suggest that TM5, together with other transcription factors RIN and SlCMB1, is involved in the regulation of fruit development and ripening.

The genus Allium L. (Amaryllidaceae), the most numerous among monocotyledonous plants, includes such economically important vegetable crops as onion (A. cepa), garlic (A. sativum) and leek (A. porrum). Leek has a high taste and proven valuable dietary properties and is one of the most popular vegetable crops in Western Europe. Despite a high importance of leek as a vegetable, this species is rarely the subject of molecular genetic studies. The genetic diversity of leeks has never been studied before. Therefore, in this work, we studied the nuclear variability (AFLP) and the chloroplast (nucleotide sequence analysis) genomes using a broad sample. For this work, 65 leek accessions were selected from the collection of the Scientific Center of Vegetable Crops, which included varieties of domestic and foreign breeding. As a result of an AFLP analysis and processing of the DNA spectra obtained, 760 fragments were identified, of which 716 were polymorphic for the leek accessions being analyzed. The calculated genetic distances between the leek samples varied from 0.4 to 0.76, which is comparable to the intraspecific polymorphism of related Allium species (onions, garlic). Analysis of the genomic structure with STRUCTURE 2.3.4 divided the leek samples into seven groups, which generally coincides with the clustering of these samples. To assess the variability of the chloroplast genome, nine sites of the chloroplast genome were sequenced in the leek samples, both non-coding (intergenic spacers rpl32-trnL, ndhJ-trnL, and intron rps16 gene), and protein coding genes (psaA, psaB, psbA, psbB, psbE, petB). The analysis of the sites of the leek chloroplast genome revealed an extremely low level of their polymorphism, only six SNPs were detected in the studied sequences with a total length of about 10,500 bp. Thus, as a result of this work, a high level of polymorphism of the leek nuclear genome was revealed, while the polymorphism of the chloroplast genome was extremely low.

In this work, a set of pea accessions obtained from the Vavilov Research Institute (VIR) collection comprising 83 P. sativum samples, including representatives of three subspecies, was studied using the AFLP method. Local cultivars for different uses with maximum ecological and geographical diversity (including those from the centers of origin of the species) were predominantly chosen for the study; a number of their morphological and biological characteristics were evaluated. We obtained 382 polymorphic AFLP fragments; each sample was characterized by a unique set of fragments. The genetic diversity of the studied material was evaluated, and a wide range of genetic differences in the investigated samples (0.07–0.27) was demonstrated. The affiliation of the samples to the certain subspecies was not confirmed by the obtained data; the ecogeographical differentiation of the samples was not reflected by the data. Factor analysis allowed us to identify the sample groups of European and Asian origin and the intermediate nature of most of the samples from the studied set of pea accessions.