Tomato plants increase their tolerance to low temperature in a chilling acclimation process entailing comprehensive transcriptional and metabolic adjustments

43 p.-9 fig.Low temperature is a major environmental stress that seriously compromises plant development, distribution and productivity. Most crops are from tropical origin and, consequently, chilling sensitive. Interestingly, however, some tropical plants, are able to augment their chilling tolerance when previously exposed to suboptimal growth temperatures. Yet, the molecular and physiological mechanisms underlying this adaptive process, termed chilling acclimation, still remain practically unknown. Here, we demonstrate that tomato plants can develop a chilling acclimation response, which includes comprehensive transcriptomic and metabolic adjustments leading to increased chilling tolerance. More important, our results reveal strong resemblances between this response and cold acclimation, the process whereby plants from temperate regions raise their freezing tolerance after exposure to low, non-freezing temperatures. Both chilling and cold acclimation are regulated by a similar set of transcription factors and hormones, and share common defence mechanisms, including the accumulation of compatible solutes, the mobilization of antioxidant systems and the rearrangement of the photosynthetic machinery. Nonetheless, we have found some important divergences that may account for the freezing sensitivity of tomato plants. The data reported in this manuscript should foster new research into the chilling acclimation response with the aim of improving tomato tolerance to low temperature.This work was supported by grants EUI2009-04074 and BIO2013-47788-R from MINECO to J.S., and EU H2020 TRADITOM (634561) and BIO2013-42193-R from MINECO to A.G.Peer reviewe

Aroma map in European woodland strawberry

Woodland strawberry (Fragaria vesca, 2x) is the diploid closest ancestor of the cultivated strawberry (Fragaria ´ annassa, 8x) and the model species for genetic studies in the Fragaria genus. It is naturally distributed all across Europe and it is appreciated for their delicate aroma and flavor. Aiming to describe the genetic and organoleptic diversity of European woodland strawberry and decipher the genetic control of its characteristic volatile compounds, we have sequenced and metabolically-phenotyped a diverse collection of 199 geographically distant European accessions. The metabolic profiling of the lines includes a set of 100 unambiguosly identified volatiles. This study has revealed genetic and metabolic differences between subpopulations with different geographical origin. In addition, Genome Wide Association Analysis points to several candidate genetic regions controlling the accumulation of volatiles compounds sharing common biosynthetic pathways. Specifically, we have detected SNPs associated to the accumulation of methyl ketones and their corresponding alcohols mapping to a small region of chromosome 4 with a reduced set of candidate genes.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Aroma Map in European Woodland Strawberry

Woodland strawberry (Fragaria vesca, 2x) is a wild, diploid ancestor of the cultivated strawberry (Fragaria ananassa, 8x), the most economically important berry crop. F. vesca is very appreciated for its intense fruity aroma, characterized by a unique combination of volatile compounds, which are absent, or accumulated at lower rates, in the commercial strawberry varieties. In addition, F. vesca presents a wide genetic diversity and it is naturally distributed across Europe. Our aim is to describe the genetic and organoleptic diversity of European woodland strawberry and decipher the genetic control of its characteristic volatile compounds. A collection of 199 accessions representing the European genetic diversity of F. vesca has been re-sequenced obtaining a set of 1.8M SNPs. In addition, the volatilome of ripe fruits was quantified in two independent harvests by GCMS providing a set of 100 unambiguously identified compounds. This study has revealed genetic and metabolic differences between subpopulations with different geographical origin. In addition, Genome-Wide Association Analysis has revealed genetic regions significantly associated to the accumulation of several metabolites that contribute to strawberry aroma, such as terpenes (alpha-farnesene, alpha-pinene, alpha-terpineol, linalool, myrtenol), lactones (g-decalactone), eugenol and mesifurane among others.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

La práctica reflexiva y la infografía como recurso didáctico

[ES] La práctica reflexiva es un aspecto que otorga calidad a la enseñanza de nivel superior. Por ello en esta propuesta innovadora se busca promover los espacios y los recursos para hacer efectiva la reflexión en las aulas universitarias. Esta comunicación pretende relatar una experiencia situada en la Universitat Jaume I de Castellón, en el Grado de Maestros/as (de Infantil y Primaria) en la asignatura de organización escolar, de primer curso. La metodología se ha centrado en el uso de la infografía (viñetas) como herramienta para iniciar la reflexión, seguida del debate dentro del grupo clase. Los resultados recogidos de las voces de los alumnos tanto a nivel de reflexión y resultados del aprendizaje, así como de satisfacción personal con el trabajo realizado, han sido muy positivos por lo cual se sugiere la continuidad de la experiencia en años sucesivos y la posible transferencia a otras asignaturas.[EN] Reflective practice is a quality aspect of higher education. Therefore, this innovative proposal seeks to promote spaces and resources to make reflection effective in University classrooms. This communication intends to relate an experience located at Jaume I University in Castellón, in the subject of school organization, in the first year of the Bachelor’s Degree of Teaching (Nursery and Primary). The methodology has been centered on infographics (vignettes) as a tool to initiate reflection and debate within the class group. The results collected from the students have been highly positive both at the level of reflection and learning outcomes and also as personal satisfaction with the work done. This is the reason why this experience has been suggested to be continued in successive years, and its transference to other subjects has been considered.Ruiz-Bernardo, P.; Vecino Ramos, S.; Rambla Nebot, JL. (2021). La práctica reflexiva y la infografía como recurso didáctico. En IN-RED 2020: VI Congreso de Innovación Educativa y Docencia en Red. Editorial Universitat Politècnica de València. 1048-1054. https://doi.org/10.4995/INRED2020.2020.12033OCS1048105

Fast determination of 40 drugs in water using large volume direct injection liquid chromatography–tandem mass spectrometry

This work describes a rapid analytical method based on direct sample injection of water samples for the simultaneous identification/quantification of 40 emerging compounds, including pharmaceuticals and drugs of abuse. The water samples were analyzed by ultra-high-performance liquid chromatography coupled to hybrid triple quadrupole mass spectrometer (UHPLC–MS/MS QqQ). Taking profit of the increasing sensitivity of nowadays tandem mass spectrometers, direct sample injection of large volumes has been an attractive alternative to pre-concentration steps. In this work, the developed methodology has been validated at three concentration levels (10, 100 and 1000 ng/L) in 10 different water samples of different types (5 effluent wastewater and 5 surface water samples). The majority of compounds could be satisfactory validated at these concentrations, showing good recoveries and precision. With only few exceptions, the limits of quantification (LOQs), estimated from the sample chromatogram at lowest spiked level tested, were below 3 ng/L. The method was applied to the analysis of 10 effluent wastewater and 10 surface water samples. Venlafaxine was the compound most frequently detected (80%) in surface water, followed by acetaminophen (70%). Regarding effluent wastewater, valsartan and 4-acetyl aminoantipyrine were detected in 9 out of 10 samples analyzed. These two compounds together with 4-formyl aminoantipyrine and naproxen showed the highest concentrations (>2000 ng/L). In these cases, a dilution step was required for a correct quantification. As an additional evaluation of the method performance, the same water samples were analyzed in another laboratory by a second analytical methodology, based on on-line solid-phase-extraction coupled to LC–MS/MS (QqQ).The authors are very grateful to Serveis Centrals d׳Instrumentació Científica (SCIC) of University Jaume I for using the Xevo TQS mass spectrometer. The financial support of the Centro de Desarrollo Tecnológico Industrial (CDTIIDI-20110823/EXP00044257), of the Spanish Ministry of Education and Science (Ref CTQ2012-36189) and of Generalitat Valenciana (research group of excellence PROMETEO/2009/054; Collaborative Research on Environment and Food Safety, ISIC/2012/016) is acknowledged

Gene-Metabolite Networks of Volatile Metabolism in Airen and Tempranillo Grape Cultivars Revealed a Distinct Mechanism of Aroma Bouquet Production

Volatile compounds are the major determinants of aroma and flavor in both grapes and wine. In this study, we investigated the emission of volatile and non-volatile compounds during berry maturation in two grape varieties (Airén and Tempranillo) throughout 2010 and 2011. HS-SPME coupled to gas chromatography and mass spectrometry was applied for the identification and relative quantitation of these compounds. Principal component analysis was performed to search for variability between the two cultivars and evolution during 10 developmental stages. Results showed that there are distinct differences in volatile compounds between cultivars throughout fruit development. Early stages were characterized in both cultivars by higher levels of some apocarotenoids such as β-cyclocitral or β-ionone, terpenoids (E)-linalool oxide and (Z)-linalool oxide and several furans, while the final stages were characterized by the highest amounts of ethanol, benzenoid phenylacetaldehyde and 2-phenylethanol, branched-amino acid-derived 3-methylbutanol and 2-methylbutanol, and a large number of lipid derivatives. Additionally, we measured the levels of the different classes of volatile precursors by using liquid chromatography coupled to high resolution mass spectrometry. In both varieties, higher levels of carotenoid compounds were detected in the earlier stages, zeaxanthin and α-carotene were only detected in Airén while neoxanthin was found only in Tempranillo; more variable trends were observed in the case of the other volatile precursors. Furthermore, we monitored the expression of homolog genes of a set of transcripts potentially involved in the biosynthesis of these metabolites, such as some glycosyl hydrolases family 1, lipoxygenases, alcohol dehydrogenases hydroperoxide lyases, O-methyltransferases and carotenoid cleavage dioxygenases during the defined developmental stages. Finally, based on Pearson correlation analyses, we explored the metabolite-metabolite fluctuations within VOCs/precursors during the berry development; as well as tentatively linking the formation of some metabolites detected to the expression of some of these genes. Our data showed that the two varieties displayed a very different pattern of relationships regarding the precursor/volatile metabolite-metabolite fluctuations, being the lipid and the carotenoid metabolism the most distinctive between the two varieties. Correlation analysis showed a higher degree of overall correlation in precursor/volatile metabolite-metabolite levels in Airén, confirming the enriched aroma bouquet characteristic of the white varieties.This work was supported by the “Junta de comunidades de Castilla-La Mancha” (JCCM) [PPII10-0062-7718] and benefited from the networking activities within the European Cooperation in Science and Technology Action CA15136 (EUROCAROTEN). GD was supported by short-term fellowships of the Quality Fruit (FA1106) European Cooperation in Science and Technology actions. OA was funded by FPCYTCLM through the INCRECYT Programme.Peer reviewedPeer Reviewe

Metabolic characterization of loci affecting sensory attributes in tomato allows an assessment of the influence of the levels of primary metabolites and volatile organic contents

Numerous studies have revealed the extent of genetic and phenotypic variation between both species and cultivars of tomato. Using a series of tomato lines resulting from crosses between a cherry tomato and three independent large fruit cultivar (Levovil, VilB, and VilD), extensive profiling of both central primary metabolism and volatile organic components of the fruit was performed. In this study, it was possible to define a number of quantitative trait loci (QTLs) which determined the levels of primary metabolites and/or volatile organic components and to evaluate their co-location with previously defined organoleptic QTLs. Correlation analyses between either the primary metabolites or the volatile organic compounds and organoleptic properties revealed a number of interesting associations, including pharmaceutical aroma–guaiacol and sourness–alanine, across the data set. Considerable correlation within the levels of primary metabolites or volatile organic compounds, respectively, were also observed. However, there was relatively little association between the levels of primary metabolites and volatile organic compounds, implying that they are not tightly linked to one another. A notable exception to this was the strong association between the levels of sucrose and those of a number of volatile organic compounds. The combined data presented here are thus discussed both with respect to those obtained recently from wide interspecific crosses of tomato and within the framework of current understanding of the chemical basis of fruit taste

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. European traditional tomatoes could be classified into several genetic groups. Two main clusters consisting of Spanish and Italian accessions showed higher genetic diversity than the remaining varieties, suggesting that these regions might be independent secondary centers of diversity with a different history. Other varieties seem to be the result of a more recent complex pattern of migrations and hybridizations among the European regions. Several polymorphic loci were associated in a genome-wide association study with fruit morphological traits in the European traditional collection. The corresponding alleles were found to contribute to the distinctive phenotypic characteristic of the genetic varietal groups. The few highly polymorphic loci associated with morphological traits in an otherwise a low-diversity population suggests a history of balancing selection, in which tomato farmers likely maintained the morphological variation by inadvertently applying a high selective pressure within different varietal types

Identification of ABA-Mediated Genetic and Metabolic Responses to Soil Flooding in Tomato (Solanum lycopersicum L. Mill)

[EN] Soil flooding is a compound abiotic stress that alters soil properties and limits atmospheric gas diffusion (O-2 and CO2) to the roots. The involvement of abscisic acid (ABA) in the regulation of soil flooding-specific genetic and metabolic responses has been scarcely studied despite its key importance as regulator in other abiotic stress conditions. To attain this objective, wild type and ABA-deficient tomatoes were subjected to short-term (24 h) soil waterlogging. After this period, gas exchange parameters were reduced in the wild type but not in ABA-deficient plants that always had higher E and g(s). Transcript and metabolite alterations were more intense in waterlogged tissues, with genotype-specific variations. Waterlogging reduced the ABA levels in the roots while inducing PYR/PYL/RCAR ABA receptors and ABA-dependent transcription factor transcripts, of which induction was less pronounced in the ABA-deficient genotype. Ethylene/O-2-dependent genetic responses (ERFVIIs, plant anoxia survival responses, and genes involved in the N-degron pathway) were induced in hypoxic tissues independently of the genotype. Interestingly, genes encoding a nitrate reductase and a phytoglobin involved in NO biosynthesis and scavenging and ERFVII stability were induced in waterlogged tissues, but to a lower extent in ABA-deficient tomato. At the metabolic level, flooding-induced accumulation of Ala was enhanced in ABA-deficient lines following a differential accumulation of Glu and Asp in both hypoxic and aerated tissues, supporting their involvement as sources of oxalacetate to feed the tricarboxylic acid cycle in waterlogged tissues and constituting a potential advantage upon long periods of soil waterlogging. The promoter analysis of upregulated genes indicated that the production of oxalacetate from Asp via Asp oxidase, energy processes such as acetyl-CoA, ATP, and starch biosynthesis, and the lignification process were likely subjected to ABA regulation. Taken together, these data indicate that ABA depletion in waterlogged tissues acts as a positive signal, inducing several specific genetic and metabolic responses to soil flooding.This work was supported by the Spanish Ministerio de Economia y Competitividad, Universitat Jaume I and Generalitat Valenciana/Fondo Europeo de Desarrollo Regional (FEDER), co-funded through grant nos. AGL2016-76574-R, UJI-B201623, UJI-B2016-24, IDIFEDER/2018/010, and UJI-B2019-24 to AG-C, VA, and MG-G, respectively. CD was supported by UJI PICD program. MG-G and JM were supported by Ramon y Cajal contracts from Spanish Ministerio de Economia y Competitividad (RYC-2016-19325 and RYC-201723645, respectively). JR was supported by a Juan de la CiervaFormacion contract from the Spanish Ministerio de Economia y Competitividad (FJCI-2016-28601).De Ollas, C.; González-Guzmán, M.; Pitarch, Z.; Matus, JT.; Candela, H.; Rambla Nebot, JL.; Granell Richart, A.... (2021). Identification of ABA-Mediated Genetic and Metabolic Responses to Soil Flooding in Tomato (Solanum lycopersicum L. Mill). Frontiers in Plant Science. 12:1-20. https://doi.org/10.3389/fpls.2021.613059S1201

Unlocking the European traditional tomato genetic resources

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. To unveil the molecular basis of Southern European tomato phenotypic diversity, we carried out the most comprehensive phenotypic and genomic variability analysis on traditional European tomato by using 1) a collection of 1,499 traditional European tomatoes (TRADITOM collection) and 2) a multipurpose core collection (TCC), comprising 227 European traditional tomato accessions from the original TRADITOM collection, that captured most of genotypic and phenotypic variation and geographical origin present in traditional tomatoPostprint (published version