Grafting improves tolerance to combined drought and heat stresses by modifying metabolism in citrus scion

Mediterranean basin and other citrus-growing areas, such as Florida or California, are among the most vulnerable regions to the impacts of global warming. Therefore, citrus will be likely subjected to increasing periods of water scarcity combined with high temperatures that will impair plant growth, development and yield. In citrus industry, grafting is used to improve varietal characteristics, such as abiotic stress tolerance. Previous research showed that under drought and heat stress conditions, Carrizo citrange (Poncirus trifoliata × Citrus sinensis) is a better rootstock than Cleopatra mandarin (Citrus reshni) because it induces a higher antioxidant activity on the scion, reducing oxidative damage and increasing plant tolerance. Here, it is shown that metabolic reconfiguration, including changes in carbohydrate and amino acid fluxes, are key responses for plant acclimation to stress conditions. Moreover, the importance of the rootstock on scion metabolic and hormonal responses to drought and heat stress combination has been addressed by using reciprocal grafting between Carrizo and Cleopatra genotypes. Thus, Carrizo as a rootstock improves the metabolic and hormonal response of Cleopatra scions to the stress combination by inducing the accumulation of protective compounds such as raffinose, galactinol and salicylic acid. In turn, Cleopatra as a rootstock reduces levels of raffinose, galactinol, proline, phenylalanine and tryptophan in Carrizo scions, which impairs plant tolerance to the stress combination. Our findings show the effect of the rootstock on scion metabolic response to stress combination and remark the importance of the rootstock in citrus plants exposed to harsh environmental conditions.Funding for open access charge: CRUE-Universitat Jaume

Color Mutations Alter the Biochemical Composition in the San Marzano Tomato Fruit

San Marzano (SM) is a traditional Italian landrace characterized by red elongated fruits, originating in the province of Naples (Italy) and cultivated worldwide. Three mutations, yellow flesh (r), green flesh (gf) and colorless fruit epidermis (y) were introduced into SM by backcross and the resulting introgression lines (ILs) produced the expected yellow, brown and pink fruit variants. In addition, ILs carrying double combinations of those mutations were obtained. The six ILs plus the SM reference were analyzed for volatile (VOC), non-polar (NP) and polar (P) metabolites. Sixty-eight VOCs were identified, and several differences evidenced in the ILs; overall gf showed epistasis over r and y and r over y. Analysis of the NP component identified 54 metabolites; variation in early carotenoids (up to lycopene) and chlorophylls characterized respectively the ILs containing r and gf. In addition, compounds belonging to the quinone and xanthophyll classes were present in genotypes carrying the r mutation at levels higher than SM. Finally, the analysis of 129 P metabolites evidenced different levels of vitamins, amino acids, lipids and phenylpropanoids in the ILs. A correlation network approach was used to investigate metabolite–metabolite relationships in the mutant lines. Altogether these differences potentially modified the hedonistic and nutritional value of the berry. In summary, single and combined mutations in gf, r and y generated interesting visual and compositional diversity in the SM landrace, while maintaining its original typolog

Comparison of metabolomic reconfiguration between Columbia and Landsberg ecotypes subjected to the combination of high salinity and increased irradiance

Background: Plants growing in the field are subjected to combinations of abiotic stresses. These conditions pose a devastating threat to crops, decreasing their yield and causing a negative economic impact on agricultural production. Metabolic responses play a key role in plant acclimation to stress and natural variation for these metabolic changes could be key for plant adaptation to fluctuating environmental conditions. Results: Here we studied the metabolomic response of two Arabidopsis ecotypes (Columbia-0 [Col] and Landsberg erecta-0 [Ler]), widely used as genetic background for Arabidopsis mutant collections, subjected to the combination of high salinity and increased irradiance. Our findings demonstrate that this stress combination results in a specific metabolic response, different than that of the individual stresses. Although both ecotypes displayed reduced growth and quantum yield of photosystem II, as well as increased foliar damage and malondialdehyde accumulation, different mechanisms to tolerate the stress combination were observed. These included a relocation of amino acids and sugars to act as potential osmoprotectants, and the accumulation of different stress-protective compounds such as polyamines or secondary metabolites. Conclusions: Our findings reflect an initial identification of metabolic pathways that differentially change under stress combination that could be considered in studies of stress combination of Arabidopsis mutants that include Col or Ler as genetic backgrounds.Metabolomic analysis was perform at Max Planck Institute of Molecular Plant Physiology in Potsdam, Germany. Hormone measurements were carried out at the central facilities (Servei Central d’Instrumentació Científica, SCIC) of the Universitat Jaume I, Spain. SIZ was supported by a Ramón y Cajal contract (RYC2020-029967-I). JLR was supported by a Juan de la Cierva-Incorporación contract (IJC2020-045612-I)

Abscisic acid promotes plant acclimation to the combination of salinity and high light stress

Plants encounter combinations of different abiotic stresses such as salinity (S) and high light (HL). These environmental conditions have a detrimental effect on plant growth and development, posing a threat to agricultural production. Metabolic changes play a crucial role in enabling plants to adapt to fluctuations in their environment. Furthermore, hormones such as abscisic acid (ABA), jasmonic acid (JA) and salicylic acid (SA) have been previously identified as regulators of plant responses to different abiotic stresses. Here we studied the response of Arabidopsis wild type (Col and Ler) plants and mutants impaired in hormone biosynthesis (aba2-11 and aba1-1 in ABA, aos in JA and sid2 in SA) to the combination of S and HL (S + HL). Our findings showed that aba2-11 plants displayed reduced growth, impaired photosystem II (PSII) function, increased leaf damage, and decreased survival compared to Col when subjected to stress combination. However, aos and sid2 mutants did not display significant changes in response to S + HL compared to Col, indicating a key role for ABA in promoting plant tolerance to S + HL and suggesting a marginal role for JA and SA in this process. In addition, we revealed differences in the metabolic response of plants to S + HL compared to S or HL. The analysis of altered metabolic pathways under S + HL suggested that the accumulation of flavonoids is ABA-dependent, whereas the accumulation of branched-chain amino acids (BCAAs) and proline is ABA-independent. Therefore, our study uncovered a key function for ABA in regulating the accumulation of different flavonoids in plants during S + HL.Funding for open access charge: CRUE-Universitat Jaume

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

[EN] 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. Quantitative trait locus (QTL) analysis, based on a genetic linkage map comprising 297 single nucleotide polymorphisms (SNPs), revealed 102 QTLs (75% not described previously) corresponding to 39 different VOCs. The SP alleles exerted a positive effect on most of the underlying apocarotenoid volatile QTLs-regarded as desirable for liking tomato-indicating that alleles inherited from SP are a valuable resource for flavor breeding. An introgression line (IL) population developed from the same parental genotypes provided 12 ILs carrying a single SP introgression and covering 85 VOC QTLs, which were characterized at three locations. The results showed that almost half of the QTLs previously identified in the RILs maintained their effect in an IL form, reinforcing the value of these QTLs for flavor/aroma breeding in cultivated tomato.We thank Erika Moro for valuable help in volatile analysis of the ILs. WB was supported by a fellowship granted by the Universidad de Costa Rica and CSIC-Spain by way of a collaboration agreement between CSIC/UCR. Volatile profiling was performed in the Metabolomic facilities of the IBMCP, CSIC (Spain). This work was supported in part by the Spanish MINECO Project AGL2015-65246-R co-financed by EU FEDER, MINECO Project AGL2011-26957, and the Bilateral agreements of Scientific and Technological Cooperation between the Spanish National Research Council (CSIC) and the Italian National Research Council (CNR). Funding for this project was provided through TRADITOM. TRADITOM has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 634561. Networking activities were supported by COST action Fruit Quality FA 1106.Rambla Nebot, JL.; Medina, A.; Fernández Del Carmen, MA.; Barrantes, W.; Grandillo, S.; Cammareri, M.; López Casado, G.... (2016). Identification, introgression, and validation of fruit volatile QTLs from a red-fruited wild tomato species. Journal of Experimental Botany. 68(3):429-442. https://doi.org/10.1093/jxb/erw455S429442683Alba, J. M., Montserrat, M., & Fernández-Muñoz, R. (2008). Resistance to the two-spotted spider mite (Tetranychus urticae) by acylsucroses of wild tomato (Solanum pimpinellifolium) trichomes studied in a recombinant inbred line population. Experimental and Applied Acarology, 47(1), 35-47. doi:10.1007/s10493-008-9192-4Abegaz, E. G., Tandon, K. S., Scott, J. W., Baldwin, E. A., & Shewfelt, R. L. (2004). Partitioning taste from aromatic flavor notes of fresh tomato (Lycopersicon esculentum, Mill) to develop predictive models as a function of volatile and nonvolatile components. Postharvest Biology and Technology, 34(3), 227-235. doi:10.1016/j.postharvbio.2004.05.023Baldwin, E. A., Goodner, K., & Plotto, A. (2008). Interaction of Volatiles, Sugars, and Acids on Perception of Tomato Aroma and Flavor Descriptors. Journal of Food Science, 73(6), S294-S307. doi:10.1111/j.1750-3841.2008.00825.xBarrantes, W., Fernández-del-Carmen, A., López-Casado, G., González-Sánchez, M. Á., Fernández-Muñoz, R., Granell, A., & Monforte, A. J. (2014). Highly efficient genomics-assisted development of a library of introgression lines of Solanum pimpinellifolium. Molecular Breeding, 34(4), 1817-1831. doi:10.1007/s11032-014-0141-0Buttery, R. G., & Ling, L. C. (1993). Volatile Components of Tomato Fruit and Plant Parts. Bioactive Volatile Compounds from Plants, 23-34. doi:10.1021/bk-1993-0525.ch003Capel, C., Fernández del Carmen, A., Alba, J. M., Lima-Silva, V., Hernández-Gras, F., Salinas, M., … Lozano, R. (2015). Wide-genome QTL mapping of fruit quality traits in a tomato RIL population derived from the wild-relative species Solanum pimpinellifolium L. Theoretical and Applied Genetics, 128(10), 2019-2035. doi:10.1007/s00122-015-2563-4Chen, G., Hackett, R., Walker, D., Taylor, A., Lin, Z., & Grierson, D. (2004). Identification of a Specific Isoform of Tomato Lipoxygenase (TomloxC) Involved in the Generation of Fatty Acid-Derived Flavor Compounds. Plant Physiology, 136(1), 2641-2651. doi:10.1104/pp.104.041608Eisen, M. B., Spellman, P. T., Brown, P. O., & Botstein, D. (1998). Cluster analysis and display of genome-wide expression patterns. Proceedings of the National Academy of Sciences, 95(25), 14863-14868. doi:10.1073/pnas.95.25.14863Fowlkes, E. B., & Mallows, C. L. (1983). A Method for Comparing Two Hierarchical Clusterings. Journal of the American Statistical Association, 78(383), 553. doi:10.2307/2288117Goulet, C., Kamiyoshihara, Y., Lam, N. B., Richard, T., Taylor, M. G., Tieman, D. M., & Klee, H. J. (2015). Divergence in the Enzymatic Activities of a Tomato and Solanum pennellii Alcohol Acyltransferase Impacts Fruit Volatile Ester Composition. Molecular Plant, 8(1), 153-162. doi:10.1016/j.molp.2014.11.007Goulet, C., Mageroy, M. H., Lam, N. B., Floystad, A., Tieman, D. M., & Klee, H. J. (2012). Role of an esterase in flavor volatile variation within the tomato clade. Proceedings of the National Academy of Sciences, 109(46), 19009-19014. doi:10.1073/pnas.1216515109Klee, H. J., & Tieman, D. M. (2013). Genetic challenges of flavor improvement in tomato. Trends in Genetics, 29(4), 257-262. doi:10.1016/j.tig.2012.12.003Kochevenko, A., Araújo, W. L., Maloney, G. S., Tieman, D. M., Do, P. T., Taylor, M. G., … Fernie, A. R. (2012). Catabolism of Branched Chain Amino Acids Supports Respiration but Not Volatile Synthesis in Tomato Fruits. Molecular Plant, 5(2), 366-375. doi:10.1093/mp/ssr108Louveau, T., Leitao, C., Green, S., Hamiaux, C., van der Rest, B., Dechy-Cabaret, O., … Chervin, C. (2010). Predicting the substrate specificity of a glycosyltransferase implicated in the production of phenolic volatiles in tomato fruit. FEBS Journal, 278(2), 390-400. doi:10.1111/j.1742-4658.2010.07962.xMageroy, M. H., Tieman, D. M., Floystad, A., Taylor, M. G., & Klee, H. J. (2011). A Solanum lycopersicum catechol-O-methyltransferase involved in synthesis of the flavor molecule guaiacol. The Plant Journal, 69(6), 1043-1051. doi:10.1111/j.1365-313x.2011.04854.xMathieu, S., Cin, V. D., Fei, Z., Li, H., Bliss, P., Taylor, M. G., … Tieman, D. M. (2008). Flavour compounds in tomato fruits: identification of loci and potential pathways affecting volatile composition. Journal of Experimental Botany, 60(1), 325-337. doi:10.1093/jxb/ern294Matsui, K., Ishii, M., Sasaki, M., Rabinowitch, H. D., & Ben-Oliel, G. (2007). Identification of an Allele Attributable to Formation of Cucumber-like Flavor in Wild Tomato Species (Solanum pennellii) That Was Inactivated during Domestication. Journal of Agricultural and Food Chemistry, 55(10), 4080-4086. doi:10.1021/jf063756bMATSUI, K., MIYAHARA, C., WILKINSON, J., HIATT, B., KNAUF, V., & KAJIWARA, T. (2000). Fatty Acid Hydroperoxide Lyase in Tomato Fruits: Cloning and Properties of a Recombinant Enzyme Expressed inEscherichia coli. Bioscience, Biotechnology, and Biochemistry, 64(6), 1189-1196. doi:10.1271/bbb.64.1189Monforte, A. J., & Tanksley, S. D. (2000). Development of a set of near isogenic and backcross recombinant inbred lines containing most of the Lycopersicon hirsutum genome in a L. esculentum genetic background: A tool for gene mapping and gene discovery. Genome, 43(5), 803-813. doi:10.1139/gen-43-5-803Orzaez, D., Medina, A., Torre, S., Fernández-Moreno, J. P., Rambla, J. L., Fernández-del-Carmen, A., … Granell, A. (2009). A Visual Reporter System for Virus-Induced Gene Silencing in Tomato Fruit Based on Anthocyanin Accumulation. Plant Physiology, 150(3), 1122-1134. doi:10.1104/pp.109.139006Rambla, J. L., Alfaro, C., Medina, A., Zarzo, M., Primo, J., & Granell, A. (2015). Tomato fruit volatile profiles are highly dependent on sample processing and capturing methods. Metabolomics, 11(6), 1708-1720. doi:10.1007/s11306-015-0824-5Rambla, J. L., Tikunov, Y. M., Monforte, A. J., Bovy, A. G., & Granell, A. (2013). The expanded tomato fruit volatile landscape. Journal of Experimental Botany, 65(16), 4613-4623. doi:10.1093/jxb/eru128Saliba-Colombani, V., Causse, M., Langlois, D., Philouze, J., & Buret, M. (2001). Genetic analysis of organoleptic quality in fresh market tomato. 1. Mapping QTLs for physical and chemical traits. Theoretical and Applied Genetics, 102(2-3), 259-272. doi:10.1007/s001220051643Salinas, M., Capel, C., Alba, J. M., Mora, B., Cuartero, J., Fernández-Muñoz, R., … Capel, J. (2012). Genetic mapping of two QTL from the wild tomato Solanum pimpinellifolium L. controlling resistance against two-spotted spider mite (Tetranychus urticae Koch). Theoretical and Applied Genetics, 126(1), 83-92. doi:10.1007/s00122-012-1961-0Sefton, M. A., Skouroumounis, G. K., Elsey, G. M., & Taylor, D. K. (2011). Occurrence, Sensory Impact, Formation, and Fate of Damascenone in Grapes, Wines, and Other Foods and Beverages. Journal of Agricultural and Food Chemistry, 59(18), 9717-9746. doi:10.1021/jf201450qShen, J., Tieman, D., Jones, J. B., Taylor, M. G., Schmelz, E., Huffaker, A., … Klee, H. J. (2014). A 13-lipoxygenase, TomloxC, is essential for synthesis of C5 flavour volatiles in tomato. Journal of Experimental Botany, 65(2), 419-428. doi:10.1093/jxb/ert382Sim, S.-C., Durstewitz, G., Plieske, J., Wieseke, R., Ganal, M. W., Van Deynze, A., … Francis, D. M. (2012). Development of a Large SNP Genotyping Array and Generation of High-Density Genetic Maps in Tomato. PLoS ONE, 7(7), e40563. doi:10.1371/journal.pone.0040563Simkin, A. J., Schwartz, S. H., Auldridge, M., Taylor, M. G., & Klee, H. J. (2004). The tomato carotenoid cleavage dioxygenase 1 genes contribute to the formation of the flavor volatiles β-ionone, pseudoionone, and geranylacetone. The Plant Journal, 40(6), 882-892. doi:10.1111/j.1365-313x.2004.02263.xSkouroumounis GK Massywestropp RA Sefton MA Williams PJ . 1993. beta-Damascenone formation in juices and wines. In: Schreier P Winterhalter P , eds. Progress in flavour precursor studies: analysis, generation, biotechnology. Proceedings of the International Conference, Würzburg, Germany, September 30–October 2, 1992, 275–278.Speirs, J., Lee, E., Holt, K., Yong-Duk, K., Steele Scott, N., Loveys, B., & Schuch, W. (1998). Genetic Manipulation of Alcohol Dehydrogenase Levels in Ripening Tomato Fruit Affects the Balance of Some Flavor Aldehydes and Alcohols. Plant Physiology, 117(3), 1047-1058. doi:10.1104/pp.117.3.1047Tadmor, Y., Fridman, E., Gur, A., Larkov, O., Lastochkin, E., Ravid, U., … Lewinsohn, E. (2002). Identification ofmalodorous, a Wild Species Allele Affecting Tomato Aroma That Was Selected against during Domestication. Journal of Agricultural and Food Chemistry, 50(7), 2005-2009. doi:10.1021/jf011237xTieman, D., Bliss, P., McIntyre, L. M., Blandon-Ubeda, A., Bies, D., Odabasi, A. Z., … Klee, H. J. (2012). The Chemical Interactions Underlying Tomato Flavor Preferences. Current Biology, 22(11), 1035-1039. doi:10.1016/j.cub.2012.04.016Tieman, D., Taylor, M., Schauer, N., Fernie, A. R., Hanson, A. D., & Klee, H. J. (2006). Tomato aromatic amino acid decarboxylases participate in synthesis of the flavor volatiles 2-phenylethanol and 2-phenylacetaldehyde. Proceedings of the National Academy of Sciences, 103(21), 8287-8292. doi:10.1073/pnas.0602469103Tieman, D., Zeigler, M., Schmelz, E., Taylor, M. G., Rushing, S., Jones, J. B., & Klee, H. J. (2010). Functional analysis of a tomato salicylic acid methyl transferase and its role in synthesis of the flavor volatile methyl salicylate. The Plant Journal, 62(1), 113-123. doi:10.1111/j.1365-313x.2010.04128.xTieman, D. M., Loucas, H. M., Kim, J. Y., Clark, D. G., & Klee, H. J. (2007). Tomato phenylacetaldehyde reductases catalyze the last step in the synthesis of the aroma volatile 2-phenylethanol. Phytochemistry, 68(21), 2660-2669. doi:10.1016/j.phytochem.2007.06.005Tieman, D. M., Zeigler, M., Schmelz, E. A., Taylor, M. G., Bliss, P., Kirst, M., & Klee, H. J. (2006). Identification of loci affecting flavour volatile emissions in tomato fruits. Journal of Experimental Botany, 57(4), 887-896. doi:10.1093/jxb/erj074Tikunov, Y., Lommen, A., de Vos, C. H. R., Verhoeven, H. A., Bino, R. J., Hall, R. D., & Bovy, A. G. (2005). A Novel Approach for Nontargeted Data Analysis for Metabolomics. Large-Scale Profiling of Tomato Fruit Volatiles. Plant Physiology, 139(3), 1125-1137. doi:10.1104/pp.105.068130Tikunov, Y. M., Molthoff, J., de Vos, R. C. H., Beekwilder, J., van Houwelingen, A., van der Hooft, J. J. J., … Bovy, A. G. (2013). NON-SMOKY GLYCOSYLTRANSFERASE1 Prevents the Release of Smoky Aroma from Tomato Fruit. The Plant Cell, 25(8), 3067-3078. doi:10.1105/tpc.113.114231Van Ooijen JW . 2006. JoinMap® 4. Software for the calculation of genetic linkage maps in experimental populations. Wageningen, The Netherlands: Kyazma BV.Vogel, J. T., Tieman, D. M., Sims, C. A., Odabasi, A. Z., Clark, D. G., & Klee, H. J. (2010). Carotenoid content impacts flavor acceptability in tomato (Solanum lycopersicum). Journal of the Science of Food and Agriculture, 90(13), 2233-2240. doi:10.1002/jsfa.4076Voorrips, R. E. (2002). MapChart: Software for the Graphical Presentation of Linkage Maps and QTLs. Journal of Heredity, 93(1), 77-78. doi:10.1093/jhered/93.1.77Zanor, M. I., Rambla, J.-L., Chaïb, J., Steppa, A., Medina, A., Granell, A., … Causse, M. (2009). 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. Journal of Experimental Botany, 60(7), 2139-2154. doi:10.1093/jxb/erp086Zorrilla-Fontanesi, Y., Rambla, J.-L., Cabeza, A., Medina, J. J., Sánchez-Sevilla, J. F., Valpuesta, V., … Amaya, I. (2012). Genetic Analysis of Strawberry Fruit Aroma and Identification of O-Methyltransferase FaOMT as the Locus Controlling Natural Variation in Mesifurane Content. Plant Physiology, 159(2), 851-870. doi:10.1104/pp.111.18831

A metabolome and transcriptome survey to tap the dynamics of fruit prolonged shelf-life and improved quality within Greek tomato germplasm

IntroductionTomato is a high economic value crop worldwide with recognized nutritional properties and diverse postharvest potential. Nowadays, there is an emerging awareness about the exploitation and utilization of underutilized traditional germplasm in modern breeding programs. In this context, the existing diversity among Greek accessions in terms of their postharvest life and nutritional value remains largely unexplored.MethodsHerein, a detailed evaluation of 130 tomato Greek accessions for postharvest and nutritional characteristics was performed, using metabolomics and transcriptomics, leading to the selection of accessions with these interesting traits. ResultsThe results showed remarkable differences among tomato Greek accessions for overall ripening parameters (color, firmness) and weight loss. On the basis of their postharvest performance, a balance between short shelf life (SSL) and long shelf life (LSL) accessions was revealed. Metabolome analysis performed on 14 selected accessions with contrasting shelf-life potential identified a total of 206 phytonutrients and volatile compounds. In turn, transcriptome analysis in fruits from the best SSL and the best LSL accessions revealed remarkable differences in the expression profiles of transcripts involved in key metabolic pathways related to fruit quality and postharvest potential. DiscussionThe pathways towards cell wall synthesis, polyamine synthesis, ABA catabolism, and steroidal alkaloids synthesis were mostly induced in the LSL accession, whereas those related to ethylene biosynthesis, cell wall degradation, isoprenoids, phenylpropanoids, ascorbic acid and aroma (TomloxC) were stimulated in the SSL accession. Overall, these data would provide valuable insights into the molecular mechanism towards enhancing shelf-life and improving flavor and aroma of modern tomato cultivars

Hydrogeological, hydrodynamic and anthropogenic factors affecting the spread of pharmaceuticals and pesticides in water resources of the Granada plain (Spain)

The anthropogenic organic contaminants contemplated in the environmental legislation, as well as those of emerging concern, threaten the quality of water resources to a degree that remains largely unknown. Contaminant exposure in the aquatic environment is a crucial element if a full understanding of the risk is pursued. There are still many uncertainties about the occurrence of organic pollutants and behavior in the hydro(geo)logical media in large scale areas. The case study of the unconfined aquifer of the Granada Plain (approximately 200 km2) is presented here. Two surface and groundwater monitoring campaigns were conducted (March 2017 and June 2018). In total, 41 out of 171 target organic pollutants were detected, at least once: 17 pharmaceuticals or drugs of abuse, 21 pesticides or their metabolites and three polyaromatic hydrocarbons. In addition, physico-chemical parameters were measured during the monitoring campaigns and hydrochemical parameters and stable isotopes (δ2H, δ18O, δ13C) were analyzed. Statistical tests confirmed the significance of seasonal changes for some of these parameters (e.g., EC, Cl-, F-, δ18O, δ13C), revealing the influence from snowmelt water input on streams and the intensification of irrigation. In March 2017, the group of pesticides (largely represented by triazines) predominated, whereas the frequency of detection of pharmaceuticals increased substantially in June 2018. Results suggest four main factors affecting the spatial and seasonal variation of organic pollutants in the aquifer: the anthropogenic factor determining the period of contaminant release throughout the year (pesticide application period and growth of tourism) along with irrigation practices that include reclaimed wastewater; unsaturated zone thickness; [...]This article is a contribution to the Research Groups RNM-308 and RNM 128 of the “Junta de Andalucía” and the project “Study, detection and behavior of emerging contaminants in anthropized watersheds in Andalusia-EMAN (P20_397)”. We are grateful to technical translation specialists GeoTranslations for proofreading the English version. We would also like to thank the Associate Editor, and the anonymous reviewers, who largely contributed to the improvement of the manuscript. Funding for open access charge: Universidad de Málaga / CBU

Identificación y caracterización de genes implicados en la maduración y la calidad de la fresa

Ripening is a critical step for the development of flavor quality in fruits. This character has significantly declined in many fleshy fruits over recent decades. This is particularly significant in strawberry (Fragaria × ananassa), where current cultivars are derived from a narrow germplasm collection. Improving fruit quality requires two important breakthroughs: 1) a precise understanding of the fruit ripening process that will allow the targeting of relevant genes, and 2) the identification of novel alleles responsible for fruit quality traits. In our project (TRANSFR-Q, Starting Grant-ERC), we aim at the identification and characterization of key transcription factors involved in fruit ripening regulation and their target genes, in order to infer the Gene Regulatory Network controlling this process. On the other hand, we are carrying out a Genome-Wide Association Study using a germplasm collection of the woodland strawberry (Fragaria vesca) in order to identify loci involved in important traits such as aroma, fruit size, and resistance to pathogens. Finally, we have implemented the use of the genome-editing tool CRISPR/Cas9 in the cultivated strawberry, which we expect to open opportunities for engineering this species to improve traits of economic importance.ERC Starting Grant ERC-2014-StG 63813

Fortification and bioaccessibility of saffron apocarotenoids in potato tubers

Carotenoids are C40 isoprenoids with well-established roles in photosynthesis, pollination, photoprotection, and hormone biosynthesis. The enzymatic or ROS-induced cleavage of carotenoids generates a group of compounds named apocarotenoids, with an increasing interest by virtue of their metabolic, physiological, and ecological activities. Both classes are used industrially in a variety of fields as colorants, supplements, and bio-actives. Crocins and picrocrocin, two saffron apocarotenoids, are examples of high-value pigments utilized in the food, feed, and pharmaceutical industries. In this study, a unique construct was achieved, namely O6, which contains CsCCD2L, UGT74AD1, and UGT709G1 genes responsible for the biosynthesis of saffron apocarotenoids driven by a patatin promoter for the generation of potato tubers producing crocins and picrocrocin. Different tuber potatoes accumulated crocins and picrocrocin ranging from 19.41–360 to 105–800 μg/g DW, respectively, with crocetin, crocin 1 [(crocetin-(β-D-glucosyl)-ester)] and crocin 2 [(crocetin)-(β-D-glucosyl)-(β-D-glucosyl)-ester)] being the main compounds detected. The pattern of carotenoids and apocarotenoids were distinct between wild type and transgenic tubers and were related to changes in the expression of the pathway genes, especially from PSY2, CCD1, and CCD4. In addition, the engineered tubers showed higher antioxidant capacity, up to almost 4-fold more than the wild type, which is a promising sign for the potential health advantages of these lines. In order to better investigate these aspects, different cooking methods were applied, and each process displayed a significant impact on the retention of apocarotenoids. More in detail, the in vitro bioaccessibility of these metabolites was found to be higher in boiled potatoes (97.23%) compared to raw, baked, and fried ones (80.97, 78.96, and 76.18%, respectively). Overall, this work shows that potatoes can be engineered to accumulate saffron apocarotenoids that, when consumed, can potentially offer better health benefits. Moreover, the high bioaccessibility of these compounds revealed that potato is an excellent way to deliver crocins and picrocrocin, while also helping to improve its nutritional value

Thermospermine catabolism increases Arabidopsis thaliana resistance to Pseudomonas viridiflava

This work investigated the roles of the tetraamine thermospermine (TSpm) by analysing its contribution to Arabidopsis basal defence against the biotrophic bacterium Pseudomonas viridiflava. The participation of polyamine oxidases (PAOs) in TSpm homeostasis and TSpm-mediated defence was also investigated. Exogenous supply of TSpm, as well as ectopic expression of the TSpm biosynthetic gene ACL5, increased Arabidopsis Col-0 resistance to P. viridiflava, while null acl5 mutants were less resistant than Col-0 plants. The above-mentioned increase in resistance was blocked by the PAO inhibitor SL-11061, thus demonstrating the participation of TSpm oxidation. Analysis of PAO genes expression in transgenic 35S::ACL5 and Col-0 plants supplied with TSpm suggests that PAO 1, 3, and 5 are the main PAOs involved in TSpm catabolism. In summary, TSpm exhibited the potential to perform defensive functions previously reported for its structural isomer Spm, and the relevance of these findings is discussed in the context of ACL5 expression and TSpm concentration in planta. Moreover, this work demonstrates that manipulation of TSpm metabolism modifies plant resistance to pathogens.The gift of SL-11061 by Dr Frydman (SLIL Biomedical Corporation, Madison, WI) is greatly appreciated. This work was supported by Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Argentina (PIP 5740, PIP 0395), Agencia Nacional de Promocion Cientifica y Tecnologica, Argentina (PICT 1119, ANPCYT), Universidad Nacional de General San Martin, Argentina (SJ10/30), Ministerio de Economia y Competitividad, Spain (BIO2011-23828), and Fundacion Carolina (postdoctoral fellowship to MM). MM, FLP, and OAR are members of the Research Career of CONICET.Marina, M.; Vera Sirera, FJ.; Rambla Nebot, JL.; Gonzalez, ME.; Blazquez Rodriguez, MA.; Carbonell Gisbert, J.; Pieckenstain, FL.... (2013). Thermospermine catabolism increases Arabidopsis thaliana resistance to Pseudomonas viridiflava. Journal of Experimental Botany. 64(5):1393-1402. https://doi.org/10.1093/jxb/ert012S13931402645Alonso, J. M. (2003). Genome-Wide Insertional Mutagenesis of Arabidopsis thaliana. Science, 301(5633), 653-657. doi:10.1126/science.1086391Alippi, A. M., Dal Bo, E., Ronco, L. B., Lopez, M. V., Lopez, A. C., & Aguilar, O. M. (2003). Pseudomonas populations causing pith necrosis of tomato and pepper in Argentina are highly diverse. Plant Pathology, 52(3), 287-302. doi:10.1046/j.1365-3059.2003.00850.xAngelini, R., Bragaloni, M., Federico, R., Infantino, A., & Porta-Pugua, A. (1993). Involvement of Polyamines, Diamine Oxidase and Peroxidase in Resistance of Chickpea to Ascochyta rabiei. Journal of Plant Physiology, 142(6), 704-709. doi:10.1016/s0176-1617(11)80906-5Clough, S. J., & Bent, A. F. (1998). Floral dip: a simplified method forAgrobacterium-mediated transformation ofArabidopsis thaliana. The Plant Journal, 16(6), 735-743. doi:10.1046/j.1365-313x.1998.00343.xCona, A., Rea, G., Angelini, R., Federico, R., & Tavladoraki, P. (2006). Functions of amine oxidases in plant development and defence. Trends in Plant Science, 11(2), 80-88. doi:10.1016/j.tplants.2005.12.009Fincato, P., Moschou, P. N., Spedaletti, V., Tavazza, R., Angelini, R., Federico, R., … Tavladoraki, P. (2010). Functional diversity inside the Arabidopsis polyamine oxidase gene family. Journal of Experimental Botany, 62(3), 1155-1168. doi:10.1093/jxb/erq341Gonzalez, M. E., Marco, F., Minguet, E. G., Carrasco-Sorli, P., Blázquez, M. A., Carbonell, J., … Pieckenstain, F. L. (2011). Perturbation of spermine synthase Gene Expression and Transcript Profiling Provide New Insights on the Role of the Tetraamine Spermine in Arabidopsis Defense against Pseudomonas viridiflava. Plant Physiology, 156(4), 2266-2277. doi:10.1104/pp.110.171413Hanzawa, Y., Imai, A., Michael, A. J., Komeda, Y., & Takahashi, T. (2002). Characterization of the spermidine synthase-related gene family inArabidopsis thaliana. FEBS Letters, 527(1-3), 176-180. doi:10.1016/s0014-5793(02)03217-9Hanzawa, Y. (2000). ACAULIS5, an Arabidopsis gene required for stem elongation, encodes a spermine synthase. The EMBO Journal, 19(16), 4248-4256. doi:10.1093/emboj/19.16.4248Igarashi, K., & Kashiwagi, K. (2000). Polyamines: Mysterious Modulators of Cellular Functions. Biochemical and Biophysical Research Communications, 271(3), 559-564. doi:10.1006/bbrc.2000.2601Imai, A., Akiyama, T., Kato, T., Sato, S., Tabata, S., Yamamoto, K. T., & Takahashi, T. (2003). Spermine is not essential for survival of Arabidopsis. FEBS Letters, 556(1-3), 148-152. doi:10.1016/s0014-5793(03)01395-4Imai, A. (2006). The dwarf phenotype of the Arabidopsis acl5 mutant is suppressed by a mutation in an upstream ORF of a bHLH gene. Development, 133(18), 3575-3585. doi:10.1242/dev.02535Jakob, K., Goss, E. M., Araki, H., Van, T., Kreitman, M., & Bergelson, J. (2002). Pseudomonas viridiflavaandP. syringae—Natural Pathogens ofArabidopsis thaliana. Molecular Plant-Microbe Interactions, 15(12), 1195-1203. doi:10.1094/mpmi.2002.15.12.1195Kakehi, J. -i., Kuwashiro, Y., Niitsu, M., & Takahashi, T. (2008). Thermospermine is Required for Stem Elongation in Arabidopsis thaliana. Plant and Cell Physiology, 49(9), 1342-1349. doi:10.1093/pcp/pcn109Kamada-Nobusada, T., Hayashi, M., Fukazawa, M., Sakakibara, H., & Nishimura, M. (2008). A Putative Peroxisomal Polyamine Oxidase, AtPAO4, is Involved in Polyamine Catabolism in Arabidopsis thaliana. Plant and Cell Physiology, 49(9), 1272-1282. doi:10.1093/pcp/pcn114Knott, J. M., Römer, P., & Sumper, M. (2007). Putative spermine synthases fromThalassiosira pseudonanaandArabidopsis thalianasynthesize thermospermine rather than spermine. FEBS Letters, 581(16), 3081-3086. doi:10.1016/j.febslet.2007.05.074Maiale, S. J., Marina, M., Sánchez, D. H., Pieckenstain, F. L., & Ruiz, O. A. (2008). In vitro and in vivo inhibition of plant polyamine oxidase activity by polyamine analogues. Phytochemistry, 69(14), 2552-2558. doi:10.1016/j.phytochem.2008.07.003Marina, M., Maiale, S. J., Rossi, F. R., Romero, M. F., Rivas, E. I., Gárriz, A., … Pieckenstain, F. L. (2008). Apoplastic Polyamine Oxidation Plays Different Roles in Local Responses of Tobacco to Infection by the Necrotrophic Fungus Sclerotinia sclerotiorum and the Biotrophic Bacterium Pseudomonas viridiflava. Plant Physiology, 147(4), 2164-2178. doi:10.1104/pp.108.122614Marini, F., Betti, L., Scaramagli, S., Biondi, S., & Torrigiani, P. (2001). Polyamine metabolism is upregulated in response to tobacco mosaic virus in hypersensitive, but not in susceptible, tobacco. New Phytologist, 149(2), 301-309. doi:10.1046/j.1469-8137.2001.00017.xMinguet, E. G., Vera-Sirera, F., Marina, A., Carbonell, J., & Blazquez, M. A. (2008). Evolutionary Diversification in Polyamine Biosynthesis. Molecular Biology and Evolution, 25(10), 2119-2128. doi:10.1093/molbev/msn161Mitsuya, Y., Takahashi, Y., Berberich, T., Miyazaki, A., Matsumura, H., Takahashi, H., … Kusano, T. (2009). Spermine signaling plays a significant role in the defense response of Arabidopsis thaliana to cucumber mosaic virus. Journal of Plant Physiology, 166(6), 626-643. doi:10.1016/j.jplph.2008.08.006Mitsuya, Y., Takahashi, Y., Uehara, Y., Berberich, T., Miyazaki, A., Takahashi, H., & Kusano, T. (2007). Identification of a novel Cys2/His2-type zinc-finger protein as a component of a spermine-signaling pathway in tobacco. Journal of Plant Physiology, 164(6), 785-793. doi:10.1016/j.jplph.2006.05.011Møller, S. G., & McPherson, M. J. (1998). Developmental expression and biochemical analysis of the Arabidopsis atao1 gene encoding an H 2 O 2 ‐generating diamine oxidase. The Plant Journal, 13(6), 781-791. doi:10.1046/j.1365-313x.1998.00080.xMoschou, P. N., Sarris, P. F., Skandalis, N., Andriopoulou, A. H., Paschalidis, K. A., Panopoulos, N. J., & Roubelakis-Angelakis, K. A. (2009). Engineered Polyamine Catabolism Preinduces Tolerance of Tobacco to Bacteria and Oomycetes. Plant Physiology, 149(4), 1970-1981. doi:10.1104/pp.108.134932Muniz, L., Minguet, E. G., Singh, S. K., Pesquet, E., Vera-Sirera, F., Moreau-Courtois, C. L., … Tuominen, H. (2008). ACAULIS5 controls Arabidopsis xylem specification through the prevention of premature cell death. Development, 135(15), 2573-2582. doi:10.1242/dev.019349Murashige, T., & Skoog, F. (1962). A Revised Medium for Rapid Growth and Bio Assays with Tobacco Tissue Cultures. Physiologia Plantarum, 15(3), 473-497. doi:10.1111/j.1399-3054.1962.tb08052.xOber, D., Gibas, L., Witte, L., & Hartmann, T. (2003). Evidence for general occurrence of homospermidine in plants and its supposed origin as by-product of deoxyhypusine synthase. Phytochemistry, 62(3), 339-344. doi:10.1016/s0031-9422(02)00553-8Oshima, T. (2007). Unique polyamines produced by an extreme thermophile, Thermus thermophilus. Amino Acids, 33(2), 367-372. doi:10.1007/s00726-007-0526-zPanicot, M., Minguet, E. G., Ferrando, A., Alcázar, R., Blázquez, M. A., Carbonell, J., … Tiburcio, A. F. (2002). A Polyamine Metabolon Involving Aminopropyl Transferase Complexes in Arabidopsis. The Plant Cell, 14(10), 2539-2551. doi:10.1105/tpc.004077Pfaffl, M. W. (2002). Relative expression software tool (REST(C)) for group-wise comparison and statistical analysis of relative expression results in real-time PCR. Nucleic Acids Research, 30(9), 36e-36. doi:10.1093/nar/30.9.e36Rambla, J. L., Vera-Sirera, F., Blázquez, M. A., Carbonell, J., & Granell, A. (2010). Quantitation of biogenic tetraamines in Arabidopsis thaliana. Analytical Biochemistry, 397(2), 208-211. doi:10.1016/j.ab.2009.10.013Rea, G., Metoui, O., Infantino, A., Federico, R., & Angelini, R. (2002). Copper Amine Oxidase Expression in Defense Responses to Wounding and Ascochyta rabiei Invasion. Plant Physiology, 128(3), 865-875. doi:10.1104/pp.010646Sagor, G. H. M., Takahashi, H., Niitsu, M., Takahashi, Y., Berberich, T., & Kusano, T. (2012). Exogenous thermospermine has an activity to induce a subset of the defense genes and restrict cucumber mosaic virus multiplication in Arabidopsis thaliana. Plant Cell Reports, 31(7), 1227-1232. doi:10.1007/s00299-012-1243-yShah, N., Thomas, T., Shirahata, A., Sigal, L. H., & Thomas, T. J. (1999). Activation of Nuclear Factor κB by Polyamines in Breast Cancer Cells†. Biochemistry, 38(45), 14763-14774. doi:10.1021/bi991291vTakahashi, Y., Berberich, T., Miyazaki, A., Seo, S., Ohashi, Y., & Kusano, T. (2003). Spermine signalling in tobacco: activation of mitogen-activated protein kinases by spermine is mediated through mitochondrial dysfunction. The Plant Journal, 36(6), 820-829. doi:10.1046/j.1365-313x.2003.01923.xTakahashi, Y., Berberich, T., Yamashita, K., Uehara, Y., Miyazaki, A., & Kusano, T. (2004). Identification of Tobacco HIN1 and Two Closely Related Genes as Spermine-Responsive Genes and their Differential Expression During the Tobacco Mosaic Virus-Induced Hypersensitive Response and During Leaf- and Flower-Senescence. Plant Molecular Biology, 54(4), 613-622. doi:10.1023/b:plan.0000038276.95539.39Takahashi, Y., Cong, R., Sagor, G. H. M., Niitsu, M., Berberich, T., & Kusano, T. (2010). Characterization of five polyamine oxidase isoforms in Arabidopsis thaliana. Plant Cell Reports, 29(9), 955-965. doi:10.1007/s00299-010-0881-1Takahashi, Y., Uehara, Y., Berberich, T., Ito, A., Saitoh, H., Miyazaki, A., … Kusano, T. (2004). A subset of hypersensitive response marker genes, including HSR203J, is the downstream target of a spermine signal transduction pathway in tobacco. The Plant Journal, 40(4), 586-595. doi:10.1111/j.1365-313x.2004.02234.xTakano, A., Kakehi, J.-I., & Takahashi, T. (2012). Thermospermine is Not a Minor Polyamine in the Plant Kingdom. Plant and Cell Physiology, 53(4), 606-616. doi:10.1093/pcp/pcs019Thomas, T., Shah, N., Klinge, C., Faaland, C., Adihkarakunnathu, S., Gallo, M., & Thomas, T. (1999). Polyamine biosynthesis inhibitors alter protein-protein interactions involving estrogen receptor in MCF-7 breast cancer cells. Journal of Molecular Endocrinology, 131-139. doi:10.1677/jme.0.0220131Tiburcio, A. F., Altabella, T., Borrell, A., & Masgrau, C. (1997). Polyamine metabolism and its regulation. Physiologia Plantarum, 100(3), 664-674. doi:10.1111/j.1399-3054.1997.tb03073.xUehara, Y., Takahashi, Y., Berberich, T., Miyazaki, A., Takahashi, H., Matsui, K., … Kusano, T. (2005). Tobacco ZFT1, a Transcriptional Repressor with a Cys2/His2 Type Zinc Finger Motif that Functions in Spermine-Signaling Pathway. Plant Molecular Biology, 59(3), 435-448. doi:10.1007/s11103-005-0272-0URANO, K., YOSHIBA, Y., NANJO, T., IGARASHI, Y., SEKI, M., SEKIGUCHI, F., … SHINOZAKI, K. (2003). Characterization of Arabidopsis genes involved in biosynthesis of polyamines in abiotic stress responses and developmental stages. Plant, Cell and Environment, 26(11), 1917-1926. doi:10.1046/j.1365-3040.2003.01108.xVera-Sirera, F., Minguet, E. G., Singh, S. K., Ljung, K., Tuominen, H., Blázquez, M. A., & Carbonell, J. (2010). Role of polyamines in plant vascular development. Plant Physiology and Biochemistry, 48(7), 534-539. doi:10.1016/j.plaphy.2010.01.011Yamakawa, H., Kamada, H., Satoh, M., & Ohashi, Y. (1998). Spermine Is a Salicylate-Independent Endogenous Inducer for Both Tobacco Acidic Pathogenesis-Related Proteins and Resistance against Tobacco Mosaic Virus Infection. Plant Physiology, 118(4), 1213-1222. doi:10.1104/pp.118.4.1213Yoda, H., Fujimura, K., Takahashi, H., Munemura, I., Uchimiya, H., & Sano, H. (2009). Polyamines as a common source of hydrogen peroxide in host- and nonhost hypersensitive response during pathogen infection. Plant Molecular Biology, 70(1-2), 103-112. doi:10.1007/s11103-009-9459-0Yoda, H., Yamaguchi, Y., & Sano, H. (2003). Induction of Hypersensitive Cell Death by Hydrogen Peroxide Produced through Polyamine Degradation in Tobacco Plants. Plant Physiology, 132(4), 1973-1981. doi:10.1104/pp.103.02473