Combined salt and low nitrate stress conditions lead to morphophysiological changes and tissue-specific transcriptome reprogramming in tomato.

Despite intense research towards the understanding of abiotic stress adaptation in tomato, the physiological adjustments and transcriptome modulation induced by combined salt and low nitrate (low N) conditions remain largely unknown. Here, three traditional tomato genotypes were grown under long-term single and combined stresses throughout a complete growth cycle. Physiological, molecular, and growth measurements showed extensive morphophysiological modifications under combined stress compared to the control, and single stress conditions, resulting in the highest penalty in yield and fruit size.

Genetic and Biotechnological Approaches to Improve Fruit Bioactive Content: A Focus on Eggplant and Tomato Anthocyanins.

Anthocyanins are a large group of water-soluble flavonoid pigments. These specialized metabolites are ubiquitous in the plant kingdom and play an essential role not only in plant reproduction and dispersal but also in responses to biotic and abiotic stresses. Anthocyanins are recognized as important health-promoting and chronic-disease-preventing components in the human diet.

Atlas of phenotypic, genotypic and geographical diversity present in the European traditional tomato.

The Mediterranean basin countries are considered secondary centres of tomato diversification. However, information on phenotypic and allelic variation of local tomato materials is still limited. Here we report on the evaluation of the largest traditional tomato collection, which includes 1499 accessions from Southern Europe.

European traditional tomatoes galore: a result of farmers' selection of a few diversity-rich loci.

A comprehensive collection of 1254 tomato accessions, corresponding to European traditional and modern varieties, early domesticated varieties, and wild relatives, was analyzed by genotyping by sequencing. A continuous genetic gradient between the traditional and modern varieties was observed. European traditional tomatoes displayed very low genetic diversity, with only 298 polymorphic loci (95% threshold) out of 64 943 total variants.

Multi-omics data integration provides insights into the post-harvest biology of a long shelf-life tomato landrace.

In this study we investigated the transcriptome and epigenome dynamics of the tomato fruit during post-harvest in a landrace belonging to a group of tomatoes (Solanum lycopersicum L.) collectively known as "Piennolo del Vesuvio", all characterized by a long shelf-life. Expression of protein-coding genes and microRNAs as well as DNA methylation patterns and histone modifications were analysed in distinct post-harvest phases.

Strategies to Modulate Specialized Metabolism in Mediterranean Crops: From Molecular Aspects to Field.

Plant specialized metabolites (SMs) play an important role in the interaction with the environment and are part of the plant defense response. These natural products are volatile, semi-volatile and non-volatile compounds produced from common building blocks deriving from primary metabolic pathways and rapidly evolved to allow a better adaptation of plants to environmental cues. Specialized metabolites include terpenes, flavonoids, alkaloids, glucosinolates, tannins, resins, etc.

Whole-genome re-sequencing of two Italian tomato landraces reveals sequence variations in genes associated with stress tolerance, fruit quality and long shelf-life traits.

Tomato is a high value crop and the primary model for fleshy fruit development and ripening. Breeding priorities include increased fruit quality, shelf life and tolerance to stresses. To contribute towards this goal, we re-sequenced the genomes of Corbarino (COR) and Lucariello (LUC) landraces, which both possess the traits of plant adaptation to water deficit, prolonged fruit shelf-life and good fruit quality.

Identification, introgression, and validation of fruit volatile QTLs from a red-fruited wild tomato species.

Volatile organic compounds (VOCs) are major determinants of fruit flavor, a primary objective in tomato breeding. A recombinant inbred line (RIL) population consisting of 169 lines derived from a cross between Solanum lycopersicum and a red-fruited wild tomato species Solanum pimpinellifolium accession (SP) was characterized for VOCs in three different seasons. Correlation and hierarchical cluster analyses were performed on the 52 VOCs identified, providing a tool for the putative assignation of individual compounds to metabolic pathways.

Resolution by recombination: breaking up Solanum pennellii introgressions.

Quantitative trait locus (QTL) genetics retains an important role in the study of biological and agronomic processes; however, its genetic resolution is often comparatively low. Community-based strategies are thus required to address this issue. Here we detail such a strategy wherein the widely used Solanum pennellii introgression lines (ILs) in the genetic background of the cultivated tomato (Solanum lycopersicum) are broken up into molecular marker-defined sublines as a community resource for map-based cloning.

Quinic acids from Aster caucasicus and from transgenic callus expressing a beta-amyrin synthase.

Several different classes of secondary metabolites, including flavonoids, triterpenoid saponins and quinic acid derivatives, are found in Aster spp. (Fam. Asteraceae).

Sensory quality of fresh French and Dutch market tomatoes: a preference mapping study with Italian consumers.

Sensory properties are important elements to evaluate the qualities of vegetable products and are also determinant factors in purchasing decision. Here we report the Italian results of a preference mapping study conducted within a larger European project with the aim of describing the preferences of European consumers in regard to the diversity of traditional and modern tomato varieties, available on the market. This study has allowed the assessment of fruit quality at 3 levels: objective description of sensory properties, consumer preference tests, and physicochemical measurements.

Enhanced triterpene saponin biosynthesis and root nodulation in transgenic barrel medic (Medicago truncatula Gaertn.) expressing a novel beta-amyrin synthase (AsOXA1) gene.

Triterpene saponins are a group of bioactive compounds abundant in the genus Medicago, and have been studied extensively for their biological and pharmacological properties. In this article, we evaluated the effects of the ectopic expression of AsOXA1 cDNA from Aster sedifolius on the production of triterpene saponins in barrel medic (Medicago truncatula Gaertn.).

Astersedifolioside A-C, three new oleane-type saponins with antiproliferative activity.

A phytochemical analysis of Aster sedifolius has led to the isolation of three novel triterpenoid saponins, based on an oleane-type skeleton and named astersedifolioside A (1), B (2) and C (3). On the basis of chemical, and 2D NMR and mass spectrometry data, the structures of the new compounds were elucidated as 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranosyl] echinocystic acid 28-[O-alpha-L-rhamnopyranosyl (1-->2)-alpha-L-arabinopyranoside] (1), 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranosyl] echinocystic acid 28-[O-beta-D-xylopyranosyl (1-->4)-O-alpha-L-rhamnopyranosyl (1-->2)-alpha-L-arabinopyranoside] (2) and 3-O-[alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl] echinocystic acid 28-[O-beta-D-xylopyranosyl (1-->4)-O-alpha-L-rhamnopyranosyl (1-->2)-alpha-L-arabinopyranoside] (3). The isolated compounds showed antiproliferative effect in KiMol, a transformed thyroid cell line.