Distinctive physiological and molecular responses to cold stress among cold-tolerant and cold-sensitive Pinus halepensis seed sources

Background: Forest species ranges are confined by environmental limitations such as cold stress. The natural range shifts of pine forests due to climate change and proactive-assisted population migration may each be constrained by the ability of pine species to tolerate low temperatures, especially in northern latitudes or in high altitudes. The aim of this study is to characterize the response of cold-tolerant versus cold-sensitive Pinus halepensis (P. halepensis) seedlings at the physiological and the molecular level under controlled cold conditions to identify distinctive features which allow us to explain the phenotypic difference. With this objective gas-exchange and water potential was determined and the photosynthetic pigments, soluble sugars, glutathione and free amino acids content were measured in seedlings of different provenances under control and cold stress conditions. Results: Glucose and fructose content can be highlighted as a potential distinctive trait for cold-tolerant P. halepensis seedlings. At the amino acid level, there was a significant increase and accumulation of glutathione, proline, glutamic acid, histidine, arginine and tryptophan along with a significant decrease of glycine. Conclusion: Our results established that the main difference between cold-tolerant and cold-sensitive seedlings of P. halepensis is the ability to accumulate the antioxidant glutathione and osmolytes such as glucose and fructose, proline and arginine.This study is a part of the research project: “Application of molecular biology techniques in forest restoration in Mediterranean environments, PAID-05-11” funded by the Universitat Politècnica de València (UPV), program for supporting R&D of new multidisciplinary research lines. The authors are grateful to the Ministerio de Economía y Competitividad AGL2014–57431-P and BIO2016–77776-P. AV was supported by project Survive-2 (CGL2015–69773-C2–2-P MINECO/FEDER) by the Spanish Government and Prometeo program (DESESTRES Generalitat Valenciana). CEAM is funded by Generalitat Valenciana

Stress tolerance mechanisms in Juncus: responses to salinity and drought in three Juncus species adapted to different natural environments

[EN] Comparative studies on the responses to salinity and drought were carried out in three Juncus species, two halophytes (Juncus maritimus Lam. and Juncus acutus L.) and one more salt-sensitive (Juncus articulatus L.). Salt tolerance in Juncus depends on the inhibition of transport of toxic ions to the aerial part. In the three taxa studied Na+ and Cl accumulated to the same extent in the roots of salt treated plants; however, ion contents were lower in the shoots and correlated with the relative salt sensitivity of the species, with the lowest levels measured in the halophytes. Activation of K+ transport at high salt concentration could also contribute to salt tolerance in the halophytes. Maintenance of cellular osmotic balance is mostly based on the accumulation of sucrose in the three species. Yet, neither the relative salt-induced increase in sugar content nor the absolute concentrations reached can explain the observed differences in salt tolerance. In contrast, proline increased significantly in the presence of salt only in the salt-tolerant J. maritimus and J. acutus, but not in J. articulatus. Similar patterns of osmolyte accumulation were observed in response to water stress, supporting a functional role of proline in stress tolerance mechanisms in JuncusThis work was partly funded by a grant to O.V. from the Spanish Ministry of Science and Innovation (Project CGL2008-00438/BOS), with contribution by the European Regional Development Fund. Mohamad Al Hassan was a recipient of an Erasmus Mundus pre-doctoral scholarship financed by the European Commission (Welcome Consortium)Al Hassan, M.; López Gresa, MP.; Boscaiu Neagu, MT.; Vicente Meana, Ó. (2016). Stress tolerance mechanisms in Juncus: responses to salinity and drought in three Juncus species adapted to different natural environments. FUNCTIONAL PLANT BIOLOGY. 43:949-960. https://doi.org/10.1071/FP16007S94996043Al Hassan, M., Chaura, J., López-Gresa, M. P., Borsai, O., Daniso, E., Donat-Torres, M. P., … Boscaiu, M. (2016). Native-Invasive Plants vs. Halophytes in Mediterranean Salt Marshes: Stress Tolerance Mechanisms in Two Related Species. Frontiers in Plant Science, 7. doi:10.3389/fpls.2016.00473Albert, R., & Popp, M. (1977). Chemical composition of halophytes from the Neusiedler Lake region in Austria. Oecologia, 27(2), 157-170. doi:10.1007/bf00345820Ashraf, M., & Foolad, M. R. (2007). Roles of glycine betaine and proline in improving plant abiotic stress resistance. Environmental and Experimental Botany, 59(2), 206-216. doi:10.1016/j.envexpbot.2005.12.006Bartels, D., & Sunkar, R. (2005). Drought and Salt Tolerance in Plants. Critical Reviews in Plant Sciences, 24(1), 23-58. doi:10.1080/07352680590910410Bates, L. S., Waldren, R. P., & Teare, I. D. (1973). Rapid determination of free proline for water-stress studies. Plant and Soil, 39(1), 205-207. doi:10.1007/bf00018060Boscaiu, M., Ballesteros, G., Naranjo, M. A., Vicente, O., & Boira, H. (2011). Responses to salt stress in Juncus acutus and J. maritimus during seed germination and vegetative plant growth. Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology, 145(4), 770-777. doi:10.1080/11263504.2011.628446Boscaiu, M., Lull, C., Llinares, J., Vicente, O., & Boira, H. (2012). Proline as a biochemical marker in relation to the ecology of two halophytic Juncus species. Journal of Plant Ecology, 6(2), 177-186. doi:10.1093/jpe/rts017Bose, J., Rodrigo-Moreno, A., & Shabala, S. (2013). ROS homeostasis in halophytes in the context of salinity stress tolerance. Journal of Experimental Botany, 65(5), 1241-1257. doi:10.1093/jxb/ert430Boyer, J. S. (1982). Plant Productivity and Environment. Science, 218(4571), 443-448. doi:10.1126/science.218.4571.443Chen, T. H. H., & Murata, N. (2008). Glycinebetaine: an effective protectant against abiotic stress in plants. Trends in Plant Science, 13(9), 499-505. doi:10.1016/j.tplants.2008.06.007Clarke, L. D., & Hannon, N. J. (1970). The Mangrove Swamp and Salt Marsh Communities of the Sydney District: III. Plant Growth in Relation to Salinity and Waterlogging. The Journal of Ecology, 58(2), 351. doi:10.2307/2258276Drabkova, L., Kirschner, J., & Vlcek, C. (2006). Phylogenetic relationships within Luzula DC. and Juncus L. (Juncaceae): A comparison of phylogenetic signals of trnL-trnF intergenic spacer, trnL intron and rbcL plastome sequence data. Cladistics, 22(2), 132-143. doi:10.1111/j.1096-0031.2006.00095.xDuBois, M., Gilles, K. A., Hamilton, J. K., Rebers, P. A., & Smith, F. (1956). Colorimetric Method for Determination of Sugars and Related Substances. Analytical Chemistry, 28(3), 350-356. doi:10.1021/ac60111a017Espinar, J. L., Garcia, L. V., & Clemente, L. (2005). Seed storage conditions change the germination pattern of clonal growth plants in Mediterranean salt marshes. American Journal of Botany, 92(7), 1094-1101. doi:10.3732/ajb.92.7.1094Espinar, J. L., García, L. V., Figuerola, J., Green, A. J., & Clemente, L. (2006). Effects of salinity and ingestion by ducks on germination patterns of Juncus subulatus seeds. Journal of Arid Environments, 66(2), 376-383. doi:10.1016/j.jaridenv.2005.11.001Fita, A., Rodríguez-Burruezo, A., Boscaiu, M., Prohens, J., & Vicente, O. (2015). Breeding and Domesticating Crops Adapted to Drought and Salinity: A New Paradigm for Increasing Food Production. Frontiers in Plant Science, 6. doi:10.3389/fpls.2015.00978Flowers, T. J., & Colmer, T. D. (2008). Salinity tolerance in halophytes*. New Phytologist, 179(4), 945-963. doi:10.1111/j.1469-8137.2008.02531.xFlowers, T. J., Hajibagheri, M. A., & Clipson, N. J. W. (1986). Halophytes. The Quarterly Review of Biology, 61(3), 313-337. doi:10.1086/415032Flowers, T. J., Munns, R., & Colmer, T. D. (2014). Sodium chloride toxicity and the cellular basis of salt tolerance in halophytes. Annals of Botany, 115(3), 419-431. doi:10.1093/aob/mcu217Gagneul, D., Aïnouche, A., Duhazé, C., Lugan, R., Larher, F. R., & Bouchereau, A. (2007). A Reassessment of the Function of the So-Called Compatible Solutes in the Halophytic Plumbaginaceae Limonium latifolium. Plant Physiology, 144(3), 1598-1611. doi:10.1104/pp.107.099820GIL, R., LULL, C., BOSCAIU, M., BAUTISTA, I., LIDÓN, A., & VICENTE, O. (2011). Soluble Carbohydrates as Osmolytes in Several Halophytes from a Mediterranean Salt Marsh. Notulae Botanicae Horti Agrobotanici Cluj-Napoca, 39(2), 09. doi:10.15835/nbha3927176Gil, R., Boscaiu, M., Lull, C., Bautista, I., Lidón, A., & Vicente, O. (2013). Are soluble carbohydrates ecologically relevant for salt tolerance in halophytes? Functional Plant Biology, 40(9), 805. doi:10.1071/fp12359Gil, R., Bautista, I., Boscaiu, M., Lidon, A., Wankhade, S., Sanchez, H., … Vicente, O. (2014). Responses of five Mediterranean halophytes to seasonal changes in environmental conditions. AoB PLANTS, 6(0), plu049-plu049. doi:10.1093/aobpla/plu049Glenn, E. (1999). Salt Tolerance and Crop Potential of Halophytes. Critical Reviews in Plant Sciences, 18(2), 227-255. doi:10.1016/s0735-2689(99)00388-3GORHAM, J., HUGHES, L., & WYN JONES, R. G. (2006). Chemical composition of salt-marsh plants from Ynys Môn (Anglesey): the concept of physiotypes. Plant, Cell & Environment, 3(5), 309-318. doi:10.1111/1365-3040.ep11581858Grieve, C. M., & Grattan, S. R. (1983). Rapid assay for determination of water soluble quaternary ammonium compounds. Plant and Soil, 70(2), 303-307. doi:10.1007/bf02374789Gupta, B., & Huang, B. (2014). Mechanism of Salinity Tolerance in Plants: Physiological, Biochemical, and Molecular Characterization. International Journal of Genomics, 2014, 1-18. doi:10.1155/2014/701596Hamamoto, S., Horie, T., Hauser, F., Deinlein, U., Schroeder, J. I., & Uozumi, N. (2015). HKT transporters mediate salt stress resistance in plants: from structure and function to the field. Current Opinion in Biotechnology, 32, 113-120. doi:10.1016/j.copbio.2014.11.025Hariadi, Y., Marandon, K., Tian, Y., Jacobsen, S.-E., & Shabala, S. (2010). Ionic and osmotic relations in quinoa (Chenopodium quinoa Willd.) plants grown at various salinity levels. Journal of Experimental Botany, 62(1), 185-193. doi:10.1093/jxb/erq257Jones, E., Simpson, D., Hodkinson, T., Chase, M., & Parnell, J. (2007). The Juncaceae-Cyperaceae Interface: A Combined Plastid Sequence Analysis. Aliso, 23(1), 55-61. doi:10.5642/aliso.20072301.07Kumari, A., Das, P., Parida, A. K., & Agarwal, P. K. (2015). Proteomics, metabolomics, and ionomics perspectives of salinity tolerance in halophytes. Frontiers in Plant Science, 6. doi:10.3389/fpls.2015.00537Munns, R., & Termaat, A. (1986). Whole-Plant Responses to Salinity. Functional Plant Biology, 13(1), 143. doi:10.1071/pp9860143Munns, R., & Tester, M. (2008). Mechanisms of Salinity Tolerance. Annual Review of Plant Biology, 59(1), 651-681. doi:10.1146/annurev.arplant.59.032607.092911Naidoo, G., & Kift, J. (2006). Responses of the saltmarsh rush Juncus kraussii to salinity and waterlogging. Aquatic Botany, 84(3), 217-225. doi:10.1016/j.aquabot.2005.10.002Niu, X., Bressan, R. A., Hasegawa, P. M., & Pardo, J. M. (1995). Ion Homeostasis in NaCl Stress Environments. Plant Physiology, 109(3), 735-742. doi:10.1104/pp.109.3.735Ozgur, R., Uzilday, B., Sekmen, A. H., & Turkan, I. (2013). Reactive oxygen species regulation and antioxidant defence in halophytes. Functional Plant Biology, 40(9), 832. doi:10.1071/fp12389Pang, Q., Chen, S., Dai, S., Chen, Y., Wang, Y., & Yan, X. (2010). Comparative Proteomics of Salt Tolerance inArabidopsis thalianaandThellungiella halophila. Journal of Proteome Research, 9(5), 2584-2599. doi:10.1021/pr100034fPartridge, T. R., & Wilson, J. B. (1987). Salt tolerance of salt marsh plants of Otago, New Zealand. New Zealand Journal of Botany, 25(4), 559-566. doi:10.1080/0028825x.1987.10410086RAVEN, J. A. (1985). TANSLEY REVIEW No. 2. REGULATION OF PH AND GENERATION OF OSMOLARITY IN VASCULAR PLANTS: A COST-BENEFIT ANALYSIS IN RELATION TO EFFICIENCY OF USE OF ENERGY, NITROGEN AND WATER. New Phytologist, 101(1), 25-77. doi:10.1111/j.1469-8137.1985.tb02816.xRodrı́guez-Navarro, A. (2000). Potassium transport in fungi and plants. Biochimica et Biophysica Acta (BBA) - Reviews on Biomembranes, 1469(1), 1-30. doi:10.1016/s0304-4157(99)00013-1Rozema, J. (1976). An Ecophysiological Study on the Response to Salt of Four Halophytic and Glycophytic Juncus Species. Flora, 165(2), 197-209. doi:10.1016/s0367-2530(17)31845-5Rozema, J. (1991). Growth, water and ion relationships of halophytic monocotyledonae and dicotyledonae; a unified concept. Aquatic Botany, 39(1-2), 17-33. doi:10.1016/0304-3770(91)90019-2Smirnoff, N., & Cumbes, Q. J. (1989). Hydroxyl radical scavenging activity of compatible solutes. Phytochemistry, 28(4), 1057-1060. doi:10.1016/0031-9422(89)80182-7Szabados, L., & Savouré, A. (2010). Proline: a multifunctional amino acid. Trends in Plant Science, 15(2), 89-97. doi:10.1016/j.tplants.2009.11.009Vicente, M. J., Conesa, E., Álvarez-Rogel, J., Franco, J. A., & Martínez-Sánchez, J. J. (2007). Effects of various salts on the germination of three perennial salt marsh species. Aquatic Botany, 87(2), 167-170. doi:10.1016/j.aquabot.2007.04.004Vinocur, B., & Altman, A. (2005). Recent advances in engineering plant tolerance to abiotic stress: achievements and limitations. Current Opinion in Biotechnology, 16(2), 123-132. doi:10.1016/j.copbio.2005.02.001Watson, E. B., & Byrne, R. (2009). Abundance and diversity of tidal marsh plants along the salinity gradient of the San Francisco Estuary: implications for global change ecology. Plant Ecology, 205(1), 113-128. doi:10.1007/s11258-009-9602-7Weimberg, R. (1987). Solute adjustments in leaves of two species of wheat at two different stages of growth in response to salinity. Physiologia Plantarum, 70(3), 381-388. doi:10.1111/j.1399-3054.1987.tb02832.xZhu, J.-K. (2001). Plant salt tolerance. Trends in Plant Science, 6(2), 66-71. doi:10.1016/s1360-1385(00)01838-

Essential oils as natural antimicrobial and antioxidant products in the agrifood industry

Consumers are aware of the dangers arising from the use of synthetic antioxidants and antimicrobials in the agrifood industry, demanding safer and “greener” alternatives. In this study, the antioxidant activity of commercial essential oils through DPPH method, their antimicrobial effects against the bacterium Pseudomonas syringae and the phytopathogenic fungus Fusarium oxysporum by means of the standardized disk method were determined. Clove along with winter savory, cinnamon and oregano essential oils as well as carvacrol showed the highest antioxidant activity comparable to reference standards. Wintergreen essential oil was the most potent inhib-itor against P. syringae growth at the highest doses (20 and 10 μL). Oregano essential oil and its main component carvacrol were able to stop the bacterium growth even at the lowest treatment (1 μL). Cinnamon, oregano and peppermint essential oils inhibited F. oxysporum development at all doses (20, 10 and 5 μL) assayed. In general, most of the essential oils displayed more anti-fungal than antibacterial and antioxidant activities. KEYWORDS:Los consumidores son conscientes del peligro derivado del uso de antioxidantes y antimicrobianos sintéticos en la industria agroalimentaria, demandando alternativas más seguras y ecológicas. En este estudio, se ha determinado la actividad antioxidante de aceites esenciales comerciales mediante el método DPPH y su efecto antimicrobiano frente a la bacteria Pseudomonas syringaey el hongo fitopatógeno Fusarium oxysporum a través del empleo del método estandarizado de disco. Los aceites esenciales de clavo, ajedrea, canela y orégano, así como carvacrol, mostraron la máxima actividad antioxidante, comparable a antioxidantes establecidos. El aceite esencial de gaulteria fue el más potente inhibidor del crecimiento de P. syringae en las dosis más altas (20 y 10 μL) ensayadas. El aceite esencial de orégano, así como su componente principal carvacrol, detuvieron el crecimiento de la bacteria incluso a la dosis más baja ensayada (1 μL). Los aceites esenciales de canela, orégano y menta inhibieron el desarrollo de F. oxysporum en todas las dosis (20, 10 y 5 μL) aplicadas. En general, la mayoría de aceites esenciales mostraron más actividad antifúngica que antibacteriana y antioxidante

Fruit flesh volatile and carotenoid profile analysis within the Cucumis melo L. species reveals unexploited variability for future genetic breeding

Aroma profile and carotenoids content of melon flesh are two important aspects influencing the quality of this fruit that have been characterized using only selected genotypes. However, the extant variability of the whole species remains unknown.A complete view of the volatile/carotenoid profiles of melon flesh was obtained analyzing 71 accessions, representing the whole diversity of the species. Gas chromatography–mass spectrometry and high‐performance liquid chromatography were used to analyze 200 volatile compounds and five carotenoids. Genotypes were classified into two main clusters (high/low aroma), but with a large diversity of differential profiles within each cluster, consistent with the ripening behavior, flesh color and proposed evolutionary and breeding history of the different horticultural groups. Our results highlight the huge amount of untapped aroma diversity of melon germplasm, especially of non‐commercial types. Also, landraces with high nutritional value with regard to carotenoids have been identified. All this knowledge will encourage melon breeding, facilitating the selection of the genetic resources more appropriate to develop cultivars with new aromatic profiles or to minimize the impact of breeding on melon quality. The newly characterized sources provide the basis for further investigations into specific genes/alleles contributing to melon flesh quality.EEA San PedroFil: Esteras, Cristina. Universidad Politécnica de Valencia. Instituto para la Conservación y Mejoramiento de la Agrodiversidad Valenciana; EspañaFil: Rambla, Jose Luis. Consejo Superior de Investigaciones Científicas. Universidad Politécnica de Valencia. Instituto de Biología Molecular y Celular de Plantas; EspañaFil: Sánchez, Gerardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; ArgentinaFil: López-Gresa, María Pilar. Consejo Superior de Investigaciones Científicas. Universidad Politécnica de Valencia. Instituto de Biología Molecular y Celular de Plantas; EspañaFil: González-Mas, María del Carmen. Instituto Valenciano de Investigaciones Agrarias.Centro de Citricultura y Producción Vegetal; EspañaFil: Fernández-Trujillo, Juan Pablo. Universidad Politécnica de Catagena. Escuela Técnica Superior de Ingenieria Agronómica. Instituto de Biotecnología Vegetal; EspañaFil: Bellés, Jose María. Consejo Superior de Investigaciones Cientificas. Universidad Politécnica de Valencia. Instituto de Biología Molecular y Celular de Plantas; EspañaFil: Granell, Antonio. Consejo Superior de Investigaciones Científicas. Universidad Politécnica de Valencia. Instituto de Biología Molecular y Celular de Plantas; EspañaFil: Picó, María Belén. Universidad Politécnica de Valencia. Instituto para la Conservación y Mejoramiento de la Agrodiversidad Valenciana; Españ

Novel inhibitors of the mitochondrial respiratory chain: Oximes and pyrrolines isolated from Penicillium brevicompactum and synthetic analogues

[EN] The capacity of inhibition of the mammalian mitochondrial respiratory chain of brevioxime 5a, a natural insecticide compound isolated from Penicillium brevicompactum culture broth, and another 15 analogue compounds, other oximes 5b and 5c; two diastereomeric pyrrolidines 1c' and 1c"; five pyrrolines 3c', 3c" (diastereomers between them), 3a, 3b, and 6; two oxazines 4c' and 4c" (also diastereomers between them); and four pyrrol derivatives 7-10, are analyzed in this paper. Compounds 3b, 3c', 3c", 4c', 4c", 5b, 5c, 6, and 10 were found to be inhibitors of the integrated electron transfer chain (NADH oxidase activity) in beef heart submitochondrial particles (SMP), establishing that all of them except compound 3b and 6 only affected to complex I of the mitochondrial respiratory chain. The most potent product was 5b, with an IC50 of 0.27 mu M, similar to the IC50 values of other known complex I inhibitors. The diastereomeric pairs 1 c'/1c", 3c'/3c", 4c'/4c", and 5c have not been previously described. Chemical characterization, on the basis of spectral data, is also shown.We acknowledge the Fundacio¿n Jose¿ y Ana Royo for a postdoctoral grant to M.C.G., and the Conserjerı¿a de Educacio¿n y Ciencia de la C. Valenciana for the doctoral grant to M.P.L. This work has been supported by Oficina de Ciencia y Tecnologı¿a. I+D projects of the Generalitat Valenciana (Project GV01- 293), the Conselleria d Agricultura, Pesca i Alimentacio¿ (Project GVCAPA00-0529), and Fondos Europeos de Desarrollo Regional (FEDERFSE) of the European Union through the Fondo de Investigacio¿n Sanitaria (FIS 01/0406).Cantin Sanz, A.; López-Gresa, MP.; Gonzalez Más, MC.; Moya Sanz, MDP.; Miranda Alonso, MÁ.; Primo Millo, J.; Romero, V.... (2005). Novel inhibitors of the mitochondrial respiratory chain: Oximes and pyrrolines isolated from Penicillium brevicompactum and synthetic analogues. Journal of Agricultural and Food Chemistry. 53(21):8296-8301. https://doi.org/10.1021/jf058075fS82968301532