#moleculargenomics

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Identification and Analysis of the Organization of sHsp Genes in Nicotiana attenuata and Solanum lycopersicum (Solanaceae) - Cytology and Ge

Abstract Low-molecular-weight heat shock proteins (sHSPs) play a key role in protecting plants from abiotic stress and are also involved in

Abstract Low-molecular-weight heat shock proteins (sHSPs) play a key role in protecting plants from abiotic stress and are also involved in growth and development processes. In this study, using bioinformatics approaches, a comprehensive analysis of the multigenic sHsp family in members of the Solanaceae family, which includes numerous food, medicinal, and ornamental plant species, was performed. As a result of a genomic screening for two members of this family, Nicotiana attenuata (coyote tobacco), Solanum lycopersicum (tomato), and the model plant Arabidopsis thaliana, 52, 45, and 34 putative sHsp genes were identified, respectively, and their chromosomal localization was determined. All tobacco genes, five tomato genes, and one Arabidopsis gene were identified for the first time. The putative sHSPs belong to 19 classes. They differ in the size of their structural domains and contain targeting signals for various cellular compartments. Most classes formed before the divergence of the phylogenetic lineages of Superrosids and Superasterids and were conserved throughout the further evolution of dicots, while some classes proved to be specific to A. thaliana or members of the Solanaceae family. Several sHsps are characterized by a clustered organization on the chromosomes, which arose through tandem duplications of individual genes during evolution. In the genomes examined, 15 sHsps were identified, encoding two to four alternative transcripts. Analysis of the promoter regions revealed numerous recognition sites for transcription factors associated with the regulation of stress responses, light signaling, phytohormone action, and various processes governing plant growth and development.

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Distribution of Two Chloroplast Haplotypes of the Invasive Weed Himalayan Balsam (Impatiens glandulifera) in Ukraine and other European Coun

Abstract One of the most well-documented cases of successful plant invasion in Europe is the rapid spread of Himalayan balsam (Impatiens gla

Abstract One of the most well-documented cases of successful plant invasion in Europe is the rapid spread of Himalayan balsam (Impatiens glandulifera Royle). Introduced from the Himalayas to Europe in the first half of the 19th century as an ornamental and nectar-producing plant, this species initially naturalized in the United Kingdom, from where it subsequently dispersed across the European continent. Despite the active invasion of I. glandulifera in Eastern Europe, the genetic diversity of its populations in this region has remained largely unexplored. In this study, we evaluated the variability of two chloroplast DNA (cpDNA) regions, trnS-G and rpl32-trnL(UAG), in I. glandulifera samples from Ukraine and compared the results with cpDNA variants from continental Europe, the United Kingdom, as well as from India and Pakistan. Our results reveal the widespread distribution of two distinct I. glandulifera haplotypes, T1-R1 and T2-R2, across continental Europe. These haplotypes differ in both cpDNA regions analyzed, and their divergence is inferred to have occurred within the species’ native range. Chloroplast DNA variation was found to be significantly higher in the native range than in the invasive range. The broad distribution of the two chloroplast haplotypes across Europe supports the hypothesis of multiple introductions of I. glandulifera into the continent. The uneven distribution of haplotypes T1-R1 and T2-R2 within Ukraine may indicate a founder effect.

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Abstract An important model system for studying the role of genetic diversity and hybridization in plant invasions is the species complex of the genus Reynoutria Houtt. Within the secondary distribution range, two species of this genus are widespread, R. japonica Houtt. and R. sachalinensis (F. Schmidt) Nakai, as well as their derivatives, the hexaploid R. × bohemica Chrtek & Chrtková and the tetraploid R. × moravica (Hodálová and Mereďa) Olshanskyi and Antonenko, which are recognized as separate species. The genetic diversity of the species of the genus Reynoutria in Ukraine is still almost unexplored by molecular methods. In this work, we determined chloroplast haplotypes for samples of R. japonica, R. sachalinensis and R. × bohemica from Ukraine and other European countries and compared them with haplotypes of Reynoutria from the primary distribution range in China and Korea. The genetic diversity of R. japonica from the primary distribution range was significantly higher compared to European samples, which are mainly represented by the haplotype J1.1. At the same time, we identified haplotypes J1.2 and J1.3 specific to the Eastern European area, which probably arose as a consequence of the divergence of the chloroplast genome within the secondary distribution range. Of the five samples morphologically identified as R. × bohemica, three carry the haplotype J1.1, which is consistent with the idea that R. japonica var. japonica was involved as a maternal form in the formation of R. × bohemica. However, a chloroplast haplotype identical to R. sachalinensis was detected in two samples from the Alpine region of Europe. These samples likely represent another hybrid species of R. × moravica. Therefore, the use of chloroplast DNA markers is crucial for identifying the donor of maternal subgenomes in hybrid forms of the genus Reynoutria.

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Genetic Diversity of Ukrainian Populations of Invasive Species of the Genus Galinsoga Assessed by ISSR-Markers - Cytology and Genetics

Abstract Two species of the genus Galinsoga, G. parviflora Cav. and G. quadriradiata Ruiz and Pav., are among the most successful invasive p

Abstract Two species of the genus Galinsoga, G. parviflora Cav. and G. quadriradiata Ruiz and Pav., are among the most successful invasive plants causing significant damage to natural- and agroecosystems. Their natural distribution range extends from North to South America, and the adventitious part of the range includes all continents except Antarctica. Despite the practical importance of G. parviflora and G. quadriradiata, the genetic diversity of European populations of these species remains unexplored. In this study, ISSR markers were used to study Ukrainian populations of G. parviflora and G. quadriradiata and compared them with plants from Poland, Lithuania, and Portugal. The results obtained indicate the low genetic diversity (Shannon’s index I = 0.124) of G. quadriradiata populations, which is probably due to the small size of the original population introduced to the Old World from America. In contrast, the genetic diversity in G. parviflora populations is significantly higher (I = 0.254). Some genotypes of G. parviflora have a wide geographical distribution and, at the same time, different genotypes occur in the same area. The data obtained are in good agreement with the hypothesis that the main way of the invasion of Galinsoga species in the Old World was escape from botanical gardens. Among the samples examined, several forms of hybrid nature were identified, probably originating from hybrids between G. parviflora and G. quadriradiata, followed by subsequent backcrossing with one of the parent species.

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Intragenomic Polymorphism of the ITS1-5.8S-ITS2 Region in Invasive Species of the Genus Reynoutria - Cytology and Genetics

Abstract The ITS1-5.8S-ITS2 (ITS1-2) region of the 35S rDNA is widely used for molecular barcoding and in the phylogenetics of plants. It is

Abstract The ITS1-5.8S-ITS2 (ITS1-2) region of the 35S rDNA is widely used for molecular barcoding and in the phylogenetics of plants. It is believed that, due to concerted evolution, all copies of 35S rDNA in eukaryotic genomes should be effectively homogenized. However, the existence of intragenomic polymorphism of the ITS1-2 region in plant genomes has recently been demonstrated, which may be a consequence of hybridization within or between species. In this study, the intragenomic polymorphism of the ITS1-2 region was evaluated using Illumina amplicon sequencing in accessions of two invasive species of the genus Reynoutria, R. japonica and R. sachalinensis, from Ukraine and Romania. Hybridization between these species can lead to the emergence of more aggressive invasive forms. The ITS1-2 sequences of the species studied were found to be represented by some major and minor subclasses/variants, indicating their incomplete homogenization. The number of major variants range from two in R. japonica to six in R. sachalinensis. The ITS1-2 variants that are widespread in the genome of one species may be present at low levels in another species, indicating possible interspecies hybridization. The obtained results show that the ITS1-2 intragenomic polymorphism must be taken into account when performing barcoding, reconstructing the phylogeny of low-level taxa, and for the identification of hybrid forms.