Past Seminars
All past seminars are uploaded to the SolSeminar Online Channel.
December 15th, 2023 - Mariela Sader
Multidisciplinary Institute of Plant Biology (IMBIV-CONICET), Córdoba - Argentina
Diversity of the repetitive DNA fraction in Solanum betaceum Cav. (SOLANACEAE)
Variation in genome size and chromosomal number and morphology are recurrent events in angiosperms, associating such characteristics with evolutionary events and speciation in plants. Eukaryotic genomes comprise a significant portion of various classes of repetitive DNA sequences. Repetitive DNA is one of the main contributors to genome size variation in higher plants, accounting for 50 to 90% of the total genome. The evolution of repetitive DNA sequences has provided information about different processes that acted in the speciation and domestication of species of interest. Analyzing the chromosomal distribution of repetitive DNA sequences will allow exploration of aspects of genomic differentiation, providing chromosomal/molecular markers relevant for inter-specific and inter-populational relationships analysis. In this seminar, I will present the tomato tree, and relatives, repetitive genome fraction. Solanum betaceum is native to the Andean region of South America and is found today in semi-wild state in northwestern Argentina. It is popular in this region as it is consumed in juices and as a fresh fruit. Solanum betaceum has a large genome size. To understand the repetitive fraction composition, we used RepeatExplorer and localized the most abundant repeats by fluorescence in situ hybridization (FISH). Tomato tree showed an accumulation of repetitive DNA sequences, especially retrotransposons, and a relative low abundance of satDNA.
Multidisciplinary Institute of Plant Biology (IMBIV-CONICET), Córdoba - Argentina
Diversity of the repetitive DNA fraction in Solanum betaceum Cav. (SOLANACEAE)
Variation in genome size and chromosomal number and morphology are recurrent events in angiosperms, associating such characteristics with evolutionary events and speciation in plants. Eukaryotic genomes comprise a significant portion of various classes of repetitive DNA sequences. Repetitive DNA is one of the main contributors to genome size variation in higher plants, accounting for 50 to 90% of the total genome. The evolution of repetitive DNA sequences has provided information about different processes that acted in the speciation and domestication of species of interest. Analyzing the chromosomal distribution of repetitive DNA sequences will allow exploration of aspects of genomic differentiation, providing chromosomal/molecular markers relevant for inter-specific and inter-populational relationships analysis. In this seminar, I will present the tomato tree, and relatives, repetitive genome fraction. Solanum betaceum is native to the Andean region of South America and is found today in semi-wild state in northwestern Argentina. It is popular in this region as it is consumed in juices and as a fresh fruit. Solanum betaceum has a large genome size. To understand the repetitive fraction composition, we used RepeatExplorer and localized the most abundant repeats by fluorescence in situ hybridization (FISH). Tomato tree showed an accumulation of repetitive DNA sequences, especially retrotransposons, and a relative low abundance of satDNA.
December 1st, 2023 - Pilar Zamora-Tavares
University of Guadalajara, Mexico
Physalis in Mexico
Physalis is a genus with 95 recognized species. It is distributed in the Americas and the Antilles naturally. The taxonomic history of Physalis is complex due to controversies regarding the diagnostic characters traditionally used for its classification. Molecular evidence shows that Physalis is paraphyletic. Our taxonomic review revealed that 61 species are distributed in Mexico, so this country is considered a center of diversification of the genus. We describe the distributions, habitats, diagnostic characters, phenology, uses, and conservation status as evaluated by the IUCN. To contribute to the monophyly of Physalis we recently proposed a nomenclatural change for Physalis microphysa and it is very likely that more nomenclatural changes are still necessary.
University of Guadalajara, Mexico
Physalis in Mexico
Physalis is a genus with 95 recognized species. It is distributed in the Americas and the Antilles naturally. The taxonomic history of Physalis is complex due to controversies regarding the diagnostic characters traditionally used for its classification. Molecular evidence shows that Physalis is paraphyletic. Our taxonomic review revealed that 61 species are distributed in Mexico, so this country is considered a center of diversification of the genus. We describe the distributions, habitats, diagnostic characters, phenology, uses, and conservation status as evaluated by the IUCN. To contribute to the monophyly of Physalis we recently proposed a nomenclatural change for Physalis microphysa and it is very likely that more nomenclatural changes are still necessary.
November 17th, 2023 - Andrea Arrones
Institute of Conservation and Improvement of the valencian agrodiversity at Polytechnic University of Valencia; Valencia, Spain
The dawn of the age of MAGIC populations: a case in eggplant
Multi-parent Advanced Generation InterCross (MAGIC) populations are panels of recombinant inbred lines (RILs) whose genomes are fine-scale mosaics resulting from the admixture of multiple founders. The incorporation of more than two inbred founder lines increases the genetic and phenotypic diversity in the final MAGIC RIL sets. The high number of cycles of parental inter-crossing gives greater opportunities for recombination compared to bi-parental crosses and dramatically increases mapping resolution. The first eggplant MAGIC population has been developed by inter-crossing seven accessions of common eggplant (Solanum melongena) from different origins and one wild accession of S. incanum species. Individuals from the third generation of selfing were phenotyped for the presence of fruit anthocyanins and chlorophylls and genotyped with the single primer enriched technology (SPET) platform. As a result, strong candidate genes have been proposed for eggplant fruit peel coloration by a genome-wide association study (GWAS). Our new inter-specific eggplant MAGIC population has demonstrated the potential of these populations for plant breeding and QTL detection. Although challenging, the selection of a wild species as a founder has further broadened the genetic diversity of the population and has contributed to the rescue of traits of interest that were lost during domestication.
Institute of Conservation and Improvement of the valencian agrodiversity at Polytechnic University of Valencia; Valencia, Spain
The dawn of the age of MAGIC populations: a case in eggplant
Multi-parent Advanced Generation InterCross (MAGIC) populations are panels of recombinant inbred lines (RILs) whose genomes are fine-scale mosaics resulting from the admixture of multiple founders. The incorporation of more than two inbred founder lines increases the genetic and phenotypic diversity in the final MAGIC RIL sets. The high number of cycles of parental inter-crossing gives greater opportunities for recombination compared to bi-parental crosses and dramatically increases mapping resolution. The first eggplant MAGIC population has been developed by inter-crossing seven accessions of common eggplant (Solanum melongena) from different origins and one wild accession of S. incanum species. Individuals from the third generation of selfing were phenotyped for the presence of fruit anthocyanins and chlorophylls and genotyped with the single primer enriched technology (SPET) platform. As a result, strong candidate genes have been proposed for eggplant fruit peel coloration by a genome-wide association study (GWAS). Our new inter-specific eggplant MAGIC population has demonstrated the potential of these populations for plant breeding and QTL detection. Although challenging, the selection of a wild species as a founder has further broadened the genetic diversity of the population and has contributed to the rescue of traits of interest that were lost during domestication.
November 3rd, 2023 - Banisha Phukela
Evolutionary Ecology Lab, School of Plant Sciences and Food security, Tel Aviv University, Israel
Evolutionary trends of floral nectary in Solanaceae
Floral nectary (FN) is an evolutionarily labile structure which is known to influence plant- pollinator relationship across angiosperms. I looked into the evolutionary trends of diverse floral nectary types in Solanaceae. Floral nectary of 23 taxa representing different clades in the family were studied using bright-field and scanning electron microscopy. FN showed considerable variation in morphology, composition of pre-nectar secretions and locations within a flower. FNs have anatomically similar structure with three distinguishable layers an outer layer of nectary epidermis, middle layers of thin-walled parenchymatous tissue with cytoplasmically rich cells, and the inner, vascularised sub-nectary parenchymatous layer of larger and loosely packed cells. It is likely that there is a shift from symmetric, lobed type of nectary in the basal subfamilies to asymmetric, annular type in the derived subfamilies which significantly links with shifts in the floral symmetry and associated pollination syndromes. Developmental genetic studies carried out so far, have underlined that few genes have been co-opted to specify floral nectary among the taxa in different clades of angiosperms. Floral nectary formation in Solanaceae occurs via CRABS CLAW developmental programme similar to the other eudicot members. There is a modification to this programme that CRC exist as paralogs, namely CRCa and CRCb in contrast to single copy in other eudicots. The origin of this paralogy is explained through phylogenetic reconstruction and microsynteny analysis which suggest that an ancestral segmental duplication event has occurred in the common ancestor of Solanaceae. The duplicated genomic segments subsequently underwent species or lineage-specific changes followed by retention of both CRCa and CRCb homologues in most of the genomes studied.
Evolutionary Ecology Lab, School of Plant Sciences and Food security, Tel Aviv University, Israel
Evolutionary trends of floral nectary in Solanaceae
Floral nectary (FN) is an evolutionarily labile structure which is known to influence plant- pollinator relationship across angiosperms. I looked into the evolutionary trends of diverse floral nectary types in Solanaceae. Floral nectary of 23 taxa representing different clades in the family were studied using bright-field and scanning electron microscopy. FN showed considerable variation in morphology, composition of pre-nectar secretions and locations within a flower. FNs have anatomically similar structure with three distinguishable layers an outer layer of nectary epidermis, middle layers of thin-walled parenchymatous tissue with cytoplasmically rich cells, and the inner, vascularised sub-nectary parenchymatous layer of larger and loosely packed cells. It is likely that there is a shift from symmetric, lobed type of nectary in the basal subfamilies to asymmetric, annular type in the derived subfamilies which significantly links with shifts in the floral symmetry and associated pollination syndromes. Developmental genetic studies carried out so far, have underlined that few genes have been co-opted to specify floral nectary among the taxa in different clades of angiosperms. Floral nectary formation in Solanaceae occurs via CRABS CLAW developmental programme similar to the other eudicot members. There is a modification to this programme that CRC exist as paralogs, namely CRCa and CRCb in contrast to single copy in other eudicots. The origin of this paralogy is explained through phylogenetic reconstruction and microsynteny analysis which suggest that an ancestral segmental duplication event has occurred in the common ancestor of Solanaceae. The duplicated genomic segments subsequently underwent species or lineage-specific changes followed by retention of both CRCa and CRCb homologues in most of the genomes studied.
Jessica Cooperstone
Horticulture and Crop Science, Food Science and Technology, The Ohio State University, USA.
Towards understanding the chemical basis for the health benefits of tomato-rich diets
Consuming a diet rich in tomatoes has been associated with a decreased risk for a number of different chronic diseases, including heart disease and various cancers. Most attention has been paid to lycopene, the red, carotenoid pigment in tomatoes, as being responsible for these effects. However, studies where whole tomatoes are administered are often more efficacious than purified lycopene, suggesting other phytochemicals from tomatoes may also play a role in conferring benefit. Recent work from our group used untargeted metabolomic approaches and identified tomato alkaloids, another class of plant secondary metabolites, in both skin and blood of mice fed tomato supplemented diets, a study that demonstrated a cancer preventative role on tomatoes in keratinocyte carcinoma. Today I will present a variety of work from both a plant science and human nutrition perspective on work my team has conducted towards understanding the chemical basis of bioactivity in tomato.
Horticulture and Crop Science, Food Science and Technology, The Ohio State University, USA.
Towards understanding the chemical basis for the health benefits of tomato-rich diets
Consuming a diet rich in tomatoes has been associated with a decreased risk for a number of different chronic diseases, including heart disease and various cancers. Most attention has been paid to lycopene, the red, carotenoid pigment in tomatoes, as being responsible for these effects. However, studies where whole tomatoes are administered are often more efficacious than purified lycopene, suggesting other phytochemicals from tomatoes may also play a role in conferring benefit. Recent work from our group used untargeted metabolomic approaches and identified tomato alkaloids, another class of plant secondary metabolites, in both skin and blood of mice fed tomato supplemented diets, a study that demonstrated a cancer preventative role on tomatoes in keratinocyte carcinoma. Today I will present a variety of work from both a plant science and human nutrition perspective on work my team has conducted towards understanding the chemical basis of bioactivity in tomato.