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[ES] Varias especies del género Lythrum (familia Lythraceae) presentan un gran interés en la Comunidad Valenciana. L. borysthenicum es una especie de pastos terofíticos temporalmente encharcados, sobre suelos arenosos y pobres, recientemente extinguida en el Parque Natural de la Albufera. Es considerada como una de las especies de interés prioritario para su conservación en la Comunidad Valenciana. L. hyssopifolia es una especie con mayor presencia que la anterior, pero incluida en la categoría UICN con la categoría LC (preocupación menor). La tercera especie, L. salicaria, es una especie de amplia distribución y con elevada presencia en las zonas húmedas del territorio valenciano. El objetivo del trabajo es conocer los límites de la tolerancia al estrés salino e hídrico en L. borysthenicum con fines de reintroducción de esta especie en el Parque Natural de la Albufera. Las otras dos especies sirven como material comparativo. Las semillas de las tres especies serán proporcionadas por el Centro para la Investigación y Experimentación Forestal (CIEF) de la Generalitat Valenciana. Una vez germinadas en semilleros en condiciones de invernadero, las plántulas se pasan a macetas individuales y se someterán a tres concentraciones crecientes de NaCl y a un tratamiento de estrés hídrico, con ausencia completa de riego. Las plantas del tratamiento control se riegan con agua. La duración del ensayo dura en función de las respuestas de las plantas. Cuando el efecto del estrés se hace notable a nivel de crecimiento de las plantas, los tratamientos finalizan y el material vegetal se muestrea para su posterior análisis (número de hojas, longitud de tallo, peso fresco, peso seco, contenido hídrico, etc). El conocimiento de los límites de tolerancia a estos dos tipos de estrés es fundamental en la toma de decisión sobre las zonas idóneas de reintroducción de plantas amenazadas. Este proyecto se efectúa en colaboración con el CIEF y la Oficina Técnica Devesa-Albufera., [EN] This work focuses on several species of the genus Lythrum (family Lythraceae), one of them with great interest of conservation in the Valencian Community. L. borysthenicumis a species of terophiticgrasses temporarily flooded, on sandy and poor soils, which has recently becomeextinct in the Albufera Natural Park. It is considered as one of the species with priority interest for conservation in the Valencian Community. L. hyssopifoliais a species with greater presence than the previous one, but considered of minor concern (least concern), a category assigned by IUCN (International Union for the Conservation of Nature). The third species, L. salicaria, is a taxon of wide distribution and with a high presence in the humid areas of the Valencian territory.The objective of the work wasto establish the limits of tolerance to water and saline stress in L. borysthenicum, knowledge useful for the reintroduction of this species in the Albufera Natural Park. L. hyssopifoliaand L. salicariawere used as comparative material.The knowledge of the limits of tolerance to these two types of stress is fundamental in the decision-making regarding the suitable zones for reintroduction of threatened plants. This project is carried out in collaboration with the Center for Forest Research and Experimentation (CIEF) of the Generalitat Valenciana (CIEF) and the Devesa-Albufera Technical Office. The seeds of the three species,provided by theCIEFwere sown in seedbeds with a mixture of soil, pearand pearliteingermination trays maintained in a growth chamber until germination. Seedlings were transferred to individual pots under greenhouse conditions a after four weeks,when plants acquired a sufficient size were initiated the salt stress treatments with twoincreasing concentrations of NaCl and a water stress treatment, by complete ceasing irrigation. The control treatment plants were irrigated with nutritive solution. When the effect of stress becamenoticeable at the level of plant growth, th

Tesis por compendio, [ES] La sequía y la salinidad son los factores ambientales que más afectan a las plantas, aunque en general, las plantas mediterráneas están bien adaptadas a las condiciones adversas. Las previsiones estiman que debido al calentamiento global las condiciones ambientales se volverán más estresantes, especialmente en las zonas semi-áridas y áridas como muchas áreas de la Península Ibérica. Estas condiciones pueden afectar a la presencia de muchas especies silvestres, en especial, de las que ya de por si están amenazadas, son raras o endémicas. Tanto la sequía como el estrés salino provocan la activación de una serie de mecanismos de defensa o respuesta de las plantas, que incluyen entre otros, el control del transporte iónico, la acumulación de solutos compatibles u osmolitos, y la activación de sistemas antioxidantes. Para contribuir a la conservación y/o reintroducción de las especies de interés en hábitats prioritarios se ha realizado un estudio multidisciplinar abarcando los parámetros que pueden afectar sus poblaciones, como el clima, el suelo, y la vegetación acompañante, junto a estudios comparativos sobre las respuestas a la sequía y a la salinidad. Para entender mejor los mecanismos de tolerancia se han incluido en el estudio además de los taxones de interés conservacionista, especies relacionadas genéticamente con diferentes niveles de tolerancia. El estudio presenta dos objetivos principales: i) establecer la tolerancia relativa al estrés hídrico y salino de las especies en base a su distribución en la naturaleza y en los análisis realizados en campo y, en función de la inhibición relativa de su crecimiento bajo condiciones provocadas de estrés; y, ii) evaluar los cambios bioquímicos inducidos por el estrés analizando diferentes mecanismos de respuesta (inhibición de la fotosíntesis, transporte iónico, acumulación de osmolitos, mecanismos antioxidantes)., [CA] La sequera i la salinitat són els factors ambientals que més afecten les plantes, encara que en general, les plantes mediterrànies estan ben adaptades a les condicions adverses. Les previsions estimen que a causa del calfament global les condicions ambientals es tornaran més estressants, especialment en les zones semi-àrides i àrides com moltes àrees de la Península Ibèrica. Aquestes condicions poden afectar la presència de moltes espècies silvestres, especialment, de les que ja de per si estan amenaçades, són rares o endèmiques. Tant la sequera com l'estrès salí provoquen l'activació d'una sèrie de mecanismes de defensa o resposta de les plantes, que inclouen entre altres, el control del transport iònic, l'acumulació de soluts compatibles u osmolits, i l'activació de sistemes antioxidants. Per a contribuir a la conservació i/o reintroducció de les espècies d'interès en hàbitats prioritaris s'ha realitzat un estudi multidisciplinari abastant els paràmetres que poden afectar les seues poblacions, com el clima, el sòl, i la vegetació acompanyant, al costat d'estudis comparatius sobre les respostes a la sequera i a la salinitat. Per a entendre millor els mecanismes de tolerància s'han inclòs en l'estudi a més dels tàxons d'interès conservacionista, espècies relacionades genèticament amb diferents nivells de tolerància. L'estudi presenta dos objectius principals: i) establir la tolerància relativa a l'estrès hídric i salí de les espècies sobre la base de la seua distribució en la naturalesa i en les anàlisis realitzades en camp i, en funció de la inhibició relativa del seu creixement sota condicions provocades d'estrès; i, ii) avaluar els canvis bioquímics induïts per l'estrès analitzant diferents mecanismes de resposta (inhibició de la fotosíntesi, transport iònic, acumulació de osmolits, mecanismes antioxidants)., [EN] Drought and salinity are the environmental factors that most affect plants, although in general Mediterranean plants are well adapted to adverse conditions. Predictions estimate that, due to global warming, environmental conditions will become more stressful, especially in semi-arid and arid areas, such as many areas of the Iberian Peninsula. These conditions may affect the presence of many wild species, especially those that are already threatened, rare or endemic. Both drought and salt stress cause the activation of a series of defence or response mechanisms in plants, which include, among others, the control of ionic transport, the accumulation of compatible solutes or osmolytes, and the activation of antioxidant systems. To contribute to the conservation and/or reintroduction of species of interest in priority habitats, a multidisciplinary study has been carried out covering parameters that may affect their populations, such as climate, soil and accompanying vegetation, together with comparative studies on responses to drought and salinity. To better understand tolerance mechanisms, genetically related species with different levels of tolerance have been included in the study, in addition to taxa of conservation interest. The study has two main objectives: i) to establish the relative tolerance to water and salt stress of the species according to their distribution in nature and based on field analyses and, according to the relative inhibition of their growth under stress-induced conditions; and, ii) to evaluate stress-induced biochemical changes by analysing different mechanisms (inhibition of photosynthesis, ionic transport, osmolyte accumulation, antioxidant mechanisms).

Tesis por compendio, [ES] Durante siglos de cultivo en la Península Ibérica después de su introducción en el siglo XVI, las judías se adaptaron a nuevos entornos, evolucionando numerosas variedades locales. Se evaluaron cultivares españoles locales de Phaseolus lunatus (frijol lima) y su resistencia a la salinidad, en dónde se expusieron las plantas a varios tratamientos de sal, con el fin de evaluar el efecto de la salinidad en el crecimiento y el rendimiento del cultivo. Se observó que el estrés salino redujo el peso fresco de los órganos aéreos, lo que permitió clasificar los cuatro genotipos según su tolerancia a la salinidad. la prolina aumentó en todos los cultivares, más notablemente en el cv. VPH-79, con las concentraciones absolutas más altas registradas en los cultivares más tolerantes a la sal. Estos hallazgos indican que P. lunatus es moderadamente tolerante a la sal y que sus principales mecanismos para adaptarse al estrés salino son el mantenimiento de altas concentraciones de K+ y la acumulación de prolina en las hojas. Por otra parte, se analizaron en invernadero 24 genotipos locales de P. vulgaris de España durante dos temporadas consecutivas. De cada genotipo, se cultivaron cinco plantas y se caracterizaron (17 rasgos cuantitativos y 15 cualitativos) utilizando los descriptores del IBPGR. Los resultados obtenidos indican una alta variabilidad para la mayoría de los rasgos, especialmente los relacionados con el rendimiento y sus componentes. Además, se analizaron las respuestas a los tratamientos por déficit hídrico y estrés salino, en cuanto a inhibición del crecimiento y contenido de prolina foliar (Pro), en 47 genotipos de Phaseolus vulgaris de diferentes orígenes. Para la mayoría de las variables de crecimiento analizadas y Pro, los efectos del cultivo, el tratamiento y sus interacciones fueron altamente significativos (p<0.001); los rasgos morfológicos de las raíces, el diámetro del tallo y el número de hojas se debieron principalmente a una variación incontrolada, [CA] Durant segles de cultiu a la Península Ibèrica després de la seva introducció en el segle XVI, les mongetes es van adaptar a nous entorns, evolucionant nombroses varietats locals. Es van avaluar conreessis espanyols locals de garrofó (fesol llima) i la seva resistència a la salinitat, a on es van exposar les plantes a diversos tractaments de sal, per tal d'avaluar l'efecte de la salinitat en el creixement i el rendiment de l'cultiu. Es va observar que l'estrès salí va reduir el pes fresc dels òrgans aeris, el que va permetre classificar els quatre genotips segons la seva tolerància a la salinitat. la prolina augmentar en tots els conreessis, més notablement en el cv. VPH-79, amb les concentracions absolutes més altes registrades en els conreessis més tolerants a la sal. Aquestes troballes indiquen que P. lunatus és moderadament tolerant a la sal i que els seus principals mecanismes per adaptar-se a l'estrès salí són el manteniment d'altes concentracions de K + i l'acumulació de prolina en les fulles. D'altra banda, es van analitzar en hivernacle 24 genotips locals de P. vulgaris d'Espanya durant dues temporades consecutives. De cada genotip, es van conrear cinc plantes i es van caracteritzar (17 trets quantitatius i 15 qualitatius) utilitzant els descriptors de l'IBPGR. Els resultats obtinguts indiquen una alta variabilitat per a la majoria dels trets, especialment els relacionats amb el rendiment i els seus components. A més, es van analitzar les respostes als tractaments per dèficit hídric i estrès salí, pel que fa a inhibició de l'creixement i contingut de prolina foliar (Pro), en 47 genotips de Phaseolus vulgaris de diferents orígens. Per a la majoria de les variables de creixement analitzades i Pro, els efectes de l'cultiu, el tractament i les seves interaccions van ser altament significatius (p <0.001); els trets morfològics de les arrels, el diàmetre de la tija i el nombre de fulls es van deure principalment a una variació incontrolada, mentre que la var, [EN] During centuries of cultivation in the Iberian Peninsula after their introduction in the 16th century, beans adapted to new environments, evolving numerous landraces.In this study was also evaluated the resistance to salinity of several local Spanish cultivars of Phaseolus lunatus L. (lima bean). Plants were subjected to various salt treatments and growth and biochemical parameters were determined. It was observed that salt stress reduced the fresh weight of aerial organs, which allowed us to classify the four genotypes according to their tolerance to salinity. In addition, proline increased in all cultivars, most notably in cv. VPH-79, with the highest absolute concentrations recorded in the most salt tolerant cultivars. These findings indicate that P. lunatus is moderately salt tolerant and that its main mechanisms for adapting to salt stress are the maintenance of high K+ concentrations and proline accumulation in leaves. In studies conducted in this research project, 24 landraces of P. vulgaris from Spain were analyzed in greenhouses during two consecutive seasons. From each genotype, five plants were grown and characterized for 17 quantitative and 15 qualitative traits using IBPGR descriptors. . The results obtained indicate high variability for most of the traits, especially those related to yield and its components. On the other hand, this study analyzed the responses to water deficit and salt stress treatments, in terms of growth inhibition and leaf proline (Pro) content, in 47 Phaseolus vulgaris genotypes of different origins. For most of the growth variables analyzed and Pro, the effects of cultivar, treatment and their interactions were highly significant (p <0.001); root morphological traits, stem diameter and number of leaves were mainly due to uncontrolled variation, whereas variation in fresh weight and water content of stems and leaves was clearly induced by stress. Under our experimental conditions, the average effects of salt stress on plant g

[ES] El cambio climático es una realidad a la que diferentes sectores socio-económicos tienen que adaptarse. Entre los efectos del calentamiento global que ya son evidentes, aparte del incremento de las temperaturas medias a nivel global, se encuentra una alteración de los patrones meteorológicos estacionales normales. Esto incluye un incremento notable en la frecuencia, duración e intensidad de lluvias torrenciales, períodos de sequía y olas de calor , al igual que la progresiva salinización secundaria de las tierras cultivadas en régimen de regadío. Dado que la sequía y la salinidad del suelo son los factores ambientales que causan las mayores pérdidas en la producción agrícola mundial, es indudable que el sector agroalimentario será uno de los más afectados por el cambio climático, que pondrá en riesgo la seguridad alimentaria al dificultar el aumento en la producción de alimentos necesario para alimentar a una población humana en continuo crecimiento. Es importante, por tanto, desarrollar cultivos mejor adaptados a estas condiciones ambientales, utilizando todas las estrategias asequibles: ingeniería genética y edición génica, y mejora genética tradicional. Como fuentes de variabilidad en programas de mejora pueden utilizarse cultivares, variedades locales o parientes silvestres del cultivo de interés que sean naturalmente más resistentes a la sequía, salinidad u otros factores de estrés. En cualquier caso, todos estos estudios requieren el conocimiento de los mecanismos de respuesta y tolerancia a estrés de los distintos cultivos. En el trabajo propuesto, en primer lugar, se van a describir y discutir los mecanismos generales de respuesta de las plantas a la sequía, a nivel fisiológico y bioquímico. Dichos mecanismos básicos y conservados incluyen, por ejemplo: i) el mantenimiento del balance osmótico celular mediante el transporte de iones y la síntesis y acumulación de osmolitos orgánicos; ii) la activación de sistemas antioxidantes, enzimáticos y no enzimáti, [EN] Climate change is a reality to which different socio-economic sectors have to adapt. Among the effects of global warming that are already evident, apart from the increase in global average temperatures, the alteration of normal seasonal weather patterns should be mentioned. This includes a notable increase in the frequency, duration and intensity of heavy rains, periods of drought and "heat waves", as well as the progressive secondary salinisation of irrigated land. Given that drought and soil salinity are the environmental factors causing the greatest losses in agricultural production worldwide, the agro-food sector will undoubtedly be one of the most affected by climate change, which will put food security at risk by hampering the increase in food production necessary to feed a continuously growing human population. Therefore, it is important to develop crops better adapted to these environmental conditions, using all available strategies: genetic engineering and gene editing, and traditional plant breeding. As sources of variability in breeding programmes, cultivars, landraces or wild relatives of the crop of interest that are naturally more resistant to drought, salinity or other stressors, can be used. In any case, all these studies require a deep knowledge of the mechanisms of stress response and stress tolerance of different crops. In the proposed work, firstly, the general mechanisms of plant responses to drought, at the physiological and biochemical level, will be described and discussed. Said basic and conserved mechanisms include, for example: i) the maintenance of the cellular osmotic balance through the transport of ions and the synthesis and accumulation of organic osmolytes; ii) the activation of antioxidant systems, enzymatic and non-enzymatic, to counteract secondary oxidative stress generated under drought conditions; iii) the synthesis of 'protective' molecules, both low-molecular-weight compounds and specific proteins. Although all plants ac

[ES] Las orquídeas son la segunda familia de flores más grande en el mundo. Poseen una indudable belleza, razón por la que se han convertido en objeto de negocios multimillonarios, pero, además, han mostrado propiedades medicinales utilizadas en el tratamiento de varias enfermedades de la piel e infecciosas, problemas en los órganos digestivo, respiratorio y reproductivo, la circulación, antitumoral, alivio del dolor y la fiebre. La orquídea con más importancia comercial y económica es Phalaenopsis spp., sin embargo, sus partes (hojas, tallo y raíces) son desechados como residuos vegetales, los cuales tienen un potencial valor añadido. Contienen fenoles, flavonoides, y actividad antioxidante que podrían ser una fuente potencial de antioxidantes naturales. Su actividad inhibitoria podría estar relacionada con la presencia de fitoquímicos como fenoles, taninos, flavonoides, saponinas, glucósidos, esteroides, terpenoides y alcaloides en sus extractos. En particular, el ácido tanínico como agente antimicrobiano precipita las proteínas previniendo el desarrollo y crecimiento de los microorganismos. Por otra parte, el acné es una de las enfermedades más comunes de la piel, la cual afecta más a menudo a los adolescentes, pero también a adultos de ambos sexos. Se trata de un desorden en las glándulas sebáceas de la piel donde las secreciones son excesivas, la implicación microbiana es considerada uno de los mecanismos que contribuye el desarrollo del acné, en particular, Propionibacterium acnes, Staphylococcus epidermidis y Staphylococcus aureus. Existen diferentes antibióticos para tratar el acné, pero, cada vez más, aparecen bacterias resistentes a estos antibióticos, sin embargo, un número elevado de plantas han mostrado inhibición contra estos microorganismos como Rosmarinus officinalis, Matricatia chamomilla, Syzygium aromaticum, Melaleuca alternifolia, Symplocos racemose, entre otras. El objetivo de este estudio es comprobar el potencial inhibitorio de extractos de Ph, [EN] The orchid family is one of the largest families of the flowering plants around the world. They have an undoubtedly beauty, the reason why they have become an object of multibillion-dollar business. They have shown medicinal properties used for treatments of different diseases as skin, infectious diseases, problems concerning the digestive, respiratory and reproduction organs, the circulation, against tumours, for pain relief and fever. The most commercially and economically important orchid is Phalaenopsis spp., however, their parts (leaves, stems, roots) are unused vegetal waste with high potential added value. They contain phenolics, flavonoids, and antioxidant activity that could be a potential source of natural antioxidants. The inhibitory activity may be linked to the presence of phytochemicals such as phenols, tannins, flavonoids, saponins, glycosides, steroids, terpenoids and alkaloids in its extracts. In particular, tannic acid acts as an antimicrobial agent that precipitate proteins and prevent the development and growth of microorganism. Acne is one of the most common skin diseases through the population which affects more often teenagers but also adults of both genders. It is a disorder of the sebaceous glands of the skin in which sebum secretion is excessive, microbial involvement is considered to be one of the main mechanisms contributing to the development of acne, in particular due to Propionibacterium acnes, Staphylococcus epidermidis and Staphylococcus aureus. There are a number of antibiotics for acne treatment, but there is a problem with the development of bacteria resistance to antibiotics, so several plants have shown inhibition to these microorganisms as Rosmarinus officinalis, Matricatia chamomilla, Syzygium aromaticum, Melaleuca alternifolia, Symplocos racemose, among others. The objective of this study is to check the potential inhibition of Phalaenopsis extracts against Propionibacterium acnes, Staphylococcus aureus and Staphylococcu

[ES] Los humedales son ecosistemas que albergan abundante biodiversidad y que desempañan una importante función hidrológica, ecológica y paisajista. En la Comunidad Valenciana se pueden encontrar diversos humedales, siendo uno de los más representativos el Parque Natural de L Albufera. De gran interés conservacionista son las comunidades de plantas halófitas, que frecuentemente incluyen taxones de gran interés, como especies endémicas, raras y amenazadas. Bupleurum tenuissimum L. crece en marismas, bordes de lagunas y cursos de agua, en suelos margosos, arcillosos o salobres. Se puede encontrar entre el nivel del mar y los 800 m de altitud, en el oeste, centro y sur de Europa. Se trata de una especie extinguida recientemente en la Albufera y catalogada como vulnerable a nivel nacional, y actualmente incluida en los programas de reintroducción en las malladas del parque. Sin embargo no se dispone de suficiente información sobre su grado de tolerancia a la salinidad y sequia, factores ambientales de gran importancia en los saladares, que condicionan en gran medida la distribución de las especies vegetales en estos ambientes. El objetivo de este proyecto es estudiar las respuestas de crecimiento en condiciones controladas de estrés salino e hídrico en Bupleurum tenuissimum, en comparación con B. fruticosum L., especie de bosque y matorral mediterráneo, sin afinidades halofíticas pero con buena resistencia al estrés hídrico. El material vegetal se obtiene por germinación de semillas proporcionadas por el CIEF (Centro para la Investigación y Experimentación Forestal). Una vez que las plantas jóvenes de las dos especies adquieren un tamaño suficientes se someterán durante 3-4 semanas a los tratamientos de estrés (sol aq. de 75 mM, 150 mM,300 mM y 450 mM de NaCl para el tratamiento de estrés salino y ausencia de riego para el tratamiento de sequía). Así mismo se mantiene un tratamiento control en el cual las plántulas se riegan con agua desionizada. Al final del ensayo se, [EN] Wetlands are ecosystems that host abundant biodiversity and play an important hydrological, ecological and landscape role. In the Valencian Community there are several wetlands, one of the most representative being the L Albufera Natural Park. Of great conservation interest are halophyte plant communities, which frequently include taxa of great interest, such as endemic, rare and threatened species. Bupleurum tenuissimum L. grows in marshes and borders of lagoons and water courses, on loamy, clayey or brackish soils, at altitudes of 0-800 m, in the west, center and south of Europe. This species, recently extinct in the Albufera Park and classified at national level as vulnerable, has been currently included in reintroduction programs in the Albufera Park. However, there is no available information on its degree of tolerance to salinity and drought, environmental factors of great importance in salt marshes, which largely condition the distribution of plant species in these environments. The objective of this project is to study the growth responses under controlled conditions of saline and water stress in Bupleurum tenuissimum, compared to B. fruticosum L., a species of forest and Mediterranean scrub, without halophytic affinities, but with good resistance to water stress. The plant material is obtained by seed germination provided by the CIEF (Center for Forest Research and Experimentation). Once the young plants of the two species acquire a sufficient size, they will undergo stress treatments for 3-4 weeks (aq. sol of 75 mM, 150 mM, 300 mM and 450 mM NaCl for the treatment of salt stress and absence of irrigation for drought treatment). Likewise, a control treatment is maintained in which the seedlings are watered with deionized water. At the end of the experiment, the plant material will be collected and a series of growth parameters are measured (such as stem and root length, number of leaves, fresh and dry weight of the aerial part and the roots). Electrica

[ES] Como consecuencia del cambio climático, la sequía y la salinidad del suelo están aumentando. Estos factores son responsables de pérdidas muy importantes en la producción agrícola mundial, por lo que el aumento de la tolerancia a sequía y salinidad en nuestros cultivos se ha convertido en una necesidad urgente. Aunque los principales cultivos utilizados sean relativamente sensibles al estrés hídrico y salino, existe una enorme variabilidad genética en las especies silvestres que puede ser utilizada para mejorar dichos cultivos. En este estudio en concreto, se ha analizado la respuesta a la sequía de nueve genotipos de Solanum spp., con el fin de evaluar su potencial para mejorar la tolerancia al estrés hídrico de la berenjena cultivada (Solanum melongena). Los genotipos que evaluar son una serie de parientes silvestres de la berenjena (S. insanum, S. incanum, S. linnaeanum y S. dasyphyllum). También se ha analizado la respuesta de algunos híbridos de S. melongena con S. insanum y S. incanum. Con este objetivo, se han realizado dos tratamientos; sequía, que consistió en la eliminación total de riego, y un tratamiento control. La evolución del crecimiento de las plantas ha sido analizada mediante diferentes parámetros morfológicos. Además, se han evaluado algunos mecanismos de tolerancia mediante el análisis de marcadores bioquímicos asociados al estrés abiótico: prolina, flavonoides y compuestos fenólicos totales. También se ha estimado el nivel de estrés oxidativo cuantificando el contenido en malondialdehído (MDA). Como resultado, el tratamiento de sequía tuvo un gran efecto sobre el crecimiento de las plantas y el contenido en agua de los tejidos. Generalmente, el estrés aumentó significativamente el contenido en MDA, prolina, flavonoides y compuestos fenólicos totales, aunque se han observado diferencias cuantitativas entre especies. Concretamente, S. dasyphyllum y una de las accesiones de S. insanum mostraron una mayor tolerancia a la sequía: INS1 destaca po, [EN] As a result of climate change, drought and salinity are increasing in the soil. These factors are the origin of the major decrease regarding the agricultural yield. For this reason, plants tolerance to drought and salinity must be urgently improved. Although main crops are relatively sensitive to water stress and salt stress, there is high genetic diversity in wild plants that can be used for the improvement of our crops. In this study, the response to drought of nine accessions of Solanum spp. was assessed with the aim of finding interesting features for the improvement of eggplant tolerance to water stress. The genotypes are a set of wild plants related to the eggplant (S. insanum S. incanum S. linnaeanum y S. dasyphyllum). Interespecific hybrids of S. melongena with these species. Interspecific hybrids between S. melongena and S. insanum y S. incanum were also assessed. The plants were subjected to two treatments: control and drought, and during this process, morphological attributes were evaluated. Furthermore, the physiological and biochemical response will be analyzed by using stress biomarkers as proline, flavonoids and total phenolic compounds. Oxidative stress was quantified by measuring malondialdehyde (MDA) content. In consequence of the drastic treatment, plant development and tissue water content were seriously affected. Generally, water deficit also caused significant increases in MDA, proline, flavonoids and total phenolics compounds. Our results show a better response to drought in the case of S. dasyphyllum and one of the accessions of S. insanum. S. dasyphyllum is capable of generating biomass properly despite the water deficit. S. insanum presents the smaller water loss. The hybrid between S. melongena and S. incanum showed a better response than the other hybrids and even than its parents. The results obtained here might be useful for future eggplant breeding programmes with the aim of drought tolerance improvement.

[ES] El cultivo en zonas semiáridas y con sequía son dos retos agrícolas antiguos. Sin embargo, la gran explosión poblacional de las últimas décadas junto con las consecuencias derivadas del Cambio Climático hace que la búsqueda de soluciones sea más acuciante. La berenjena es un cultivo muy extendido en el mundo sobre el cual no se han realizado estudios sobre su posible adaptación a estas condiciones y sobre el potencial genético de sus especies relacionadas. Una de las respuestas al estrés salino e hídrico es la acción de enzimas antioxidantes. En este contexto, los objetivos del trabajo fueron: i) evaluar la tolerancia al estrés abiótico en berenjena (S. melongena), en uno de sus parientes silvestres (S. insanum) y sus híbridos, ii) analizar las respuestas antioxidantes enzimáticas a la salinidad y a la sequía de dichas accesiones. Para ello, tras someter a las plantas a los estreses mencionados se analizó el desarrollo de las plantas, sus niveles de H2O2 y la actividad específica de las enzimas: superóxido dismutasa, catalasa y glutatión reductasa. Las plantas evaluadas no se vieron afectadas gravemente en su desarrollo debido a los tratamientos de salinidad, mientras que la sequía sí afectó al desarrollo de las plantas. En ningún caso se observó una actividad enzimática antioxidante alterada frente al estrés. Al contrastar estos resultados con la bibliografía se puede concluir que los genotipos estudiados son capaces de mantener el balance osmótico a nivel celular sin necesidad de llegar a un estado de estrés oxidativo que induzca la actividad enzimática antioxidante. Para futuros estudios se recomienda aumentar el estrés para conseguir una respuesta más intensa y probar otros genotipos para comprobar si esta respuesta es generalizada en berenjena y sus especies relacionadas., [EN] Crops in semi-arid and drought areas are two old agricultural challenges. However, the great population explosion of the last decades together with the consequences derived from Climate Change makes the search for solutions more pressing. The eggplant is a widespread crop in the world on which no studies have been carried out on its possible adaptation to these conditions and on the genetic potential of its related species. One of the responses to saline and hydric stress is the action of antioxidant enzymes. In this context, the objectives of the work were: i) to evaluate the tolerance to abiotic stress in eggplant (S. melongena), in one of its wild relatives (S. insanum) and its hybrids, ii) to analyze the enzymatic antioxidant responses to the salinity and drought of these accessions. To this end, after subjecting the plants to the aforementioned stresses, the development of the plants, their H2O2 levels and the specific activity of the enzymes: superoxide dismutase, catalase and glutathione reductase were analysed. The plants evaluated were not seriously affected in their development due to the salinity treatments, while the drought affected the development of the plants. In no case was an antioxidant enzymatic activity altered in the face of stress observed. When contrasting these results with the bibliography, it can be concluded that the genotypes studied are capable of maintaining the osmotic balance at the cellular level without the need to reach a state of oxidative stress that induces antioxidant enzymatic activity. For future studies it is recommended to increase stress to achieve a more intense response and to test other genotypes to see if this response is generalized in eggplant and its related species.

El objetivo principal de este proyecto es identificar los niveles de osmolitos en plantas tolerantes a estrés. El trabajo se enmarca dentro del proyecto de investigación “Respuestas de las plantas al estrés abiótico: Correlación con las características edáficas de sus hábitats naturales”.

Tesis por compendio, [EN] Abstract Introduction Salinity and drought are the most important environmental stress conditions reducing crop yields worldwide and limiting the distribution of wild plants in nature. Soil salinity, especially secondary salinity caused by anthropogenic practices, such as prolonged irrigation, lead to substantial agricultural yield losses, especially in arid and semiarid regions. Drought, caused by reduced water content in the soil, occurs due to disorders in nature's water cycle, chiefly when evapotranspiration exceeds precipitation in a certain area, to the point where soil water reserves can no longer support plant growth. Drought and salt stress trigger the activation of a series of basic stress mechanisms that includes among others, the control of ion transport, exclusion and compartmentalization, as well as the accumulation of compatible solutes ('osmolytes'), and the activation of antioxidant systems. These mechanisms are conserved in all plants, stress tolerant and sensitive alike, and don't necessarily confer tolerance. To decipher those mechanisms and have a better understanding on the contribution of different stress responses to the stress tolerance of a given species, we have carried out comparative studies on the responses to drought and salinity in a number of genetically related taxa with different tolerance potentials. Methodology The experimental approach was mostly based on i) establishing the relative tolerance to water and salt stress in the studied species from their distribution in nature (in the case of wild species) and through the relative inhibition of growth in the presence of stress, and ii) correlating changes in the levels of biochemical 'stress markers' associated to specific response pathways (ion transport, osmolyte accumulation¿) upon stress treatments, with the already established relative tolerance to stress. This strategy proved to be appropriate to distinguish mere general responses to stress from those mechanisms relevant, [ES] Resumen Introducción La salinidad y la sequía son las condiciones de estrés ambiental más importantes, que reducen los rendimientos de los cultivos en todo el mundo y que limitan la distribución de las plantas silvestres en la naturaleza. La salinidad del suelo, especialmente la salinización secundaria causada por prácticas antropogénicas, como la irrigación prolongada, conducen a pérdidas importantes de rendimiento agrícola, especialmente en las regiones áridas y semiáridas. La sequía, provocada por la reducción de contenido de agua en el suelo, se produce debido a alteraciones en el ciclo del agua en la naturaleza, principalmente cuando la evapotranspiración excede la precipitación en un área determinada, hasta el punto que las reservas de agua del suelo ya no pueden soportar el crecimiento de la planta. La sequía y el estrés salino desencadenan la activación de una serie de mecanismos básicos de respuesta, que incluyen entre otros el control del transporte, la exclusión y la compartimentación de iones, así como la acumulación de solutos compatibles ('osmolitos'), y la activación de sistemas antioxidantes. Estos mecanismos están conservados en todas las plantas, tolerantes y sensibles a estrés por igual, y no confieren necesariamente tolerancia. Para descifrar estos mecanismos y conseguir una mejor comprensión de la contribución de diferentes respuestas a estrés a la tolerancia al estrés en una especie dada, hemos llevado a cabo estudios comparativos sobre las respuestas a la sequía y la salinidad, en un número de taxones relacionados genéticamente con diferentes potenciales de tolerancia. Metodología El enfoque experimental se basó principalmente en i) establecer la tolerancia relativa al estrés hídrico y al estrés salino en las especies estudiadas, a partir de su distribución en la naturaleza (en el caso de especies silvestres) y atendiendo a la inhibición relativa de su crecimiento en presencia de estrés, y ii) correlacionar cambios en los niveles de 'marc, [CA] Resum Introducció La salinitat i la sequera són les condicions d'estrès ambiental més importants, que redueixen els rendiments dels cultius a tot el món i que limiten la distribució de les plantes silvestres en la naturalesa. La salinitat del sòl, especialment la salinització secundària causada per pràctiques antropogèniques, com la irrigació perllongada, condueixen a pèrdues importants de rendiment agrícola, especialment en les regions àrides i semiàrides. La sequera, provocada per la reducció de contingut d'aigua en el sòl, es produeix a causa d'alteracions en el cicle de l'aigua en la naturalesa, principalment quan la evapotranspiració excedeix la precipitació en un àrea determinada, fins al punt que les reserves d'aigua del sòl ja no poden suportar el creixement de la planta. La sequera i l'estrès salí desencadenen l'activació d'una sèrie de mecanismes bàsics de resposta, que inclouen entre uns altres el control del transport, l'exclusió i la compartimentació d'ions, així com l'acumulació de soluts compatibles ('osmolits'), i l'activació de sistemes antioxidants. Aquests mecanismes estan conservats en totes les plantes, tolerants i sensibles a estrès per igual, i no confereixen necessàriament tolerància. Per a desxifrar aquests mecanismes i aconseguir una millor comprensió de la contribució de diferents respostes a estrès a la tolerància a l'estrès en una espècie donada, hem dut a terme estudis comparatius sobre les respostes a la sequera i la salinitat, en un nombre de taxons relacionats genèticament amb diferents potencials de tolerància. Metodologia L'enfocament experimental es va basar principalment en i) establir la tolerància relativa a l'estrès hídric i a l'estrès salí en les espècies estudiades, a partir de la seua distribució en la naturalesa (en el cas d'espècies silvestres) i atenent a la inhibició relativa de el seu creixement en presència d'estrès, i ii) correlacionar canvis en els nivells de 'marcadors bioquímics d'estrès' associats a vies esp

Análisis del desarrollo de plantas tolerantes a estrés abiótico

[EN]The salt marshes located in the Albufera Natural Park are ecosystems of great interest, which require great conservation efforts, since in the past they have been subjected to a great environmental impact by earthworks and artificial drains in order to clean the area facing future urban developments. In previous decades, the morphological recovery of these unique and highly altered habitats has been carried out. At the moment, the priority in the management programs is the recovery of the original coverage of the structural species, fundamental for the salt marshes functioning, as well as the conservation and reintroduction of endemic or rare species, previously present in the area. In this sense, it is necessary to increase the knowledge on the salt marsh plant species, in particular on those less known or rare. The species selected for this project are endemics belonging to the genus Limonium. The levels of tolerance to the abiotic stress of the diverse species of Limonium differ, some being able to endure conditions of greater salinity and / or hydric stress. Tolerance to abiotic stress is a fundamental factor in the distribution of species and for this reason the knowledge of the degree of plants¿ tolerance is the first step in the reintroduction programs of salt marsh species. Aims: For this project were selected several endemic species of the genus Limonium, growing in different salt marshes in the region of Valencia. The objectives of this project are the following: 1) to characterize the physical environment in the sampling areas 2) to analyze the plant communities present in these areas 3) to check the germination of seeds under different conditions 4) to test the growth of plants in greenhouse under various conditions of abiotic stress 5) to analyze plant responses to stress Methodology: 1) Field survey and mapping of the selected populations 2) Soil analysis 3) Bioclimatic analysis 4) Seed germination on Petri dishes 5) Growth of plants under controll, [ES] Los saladares situados en el Parque Natural de la Albufera son ecosistemas de gran interés, que requieren grandes esfuerzos de conservación, ya que en el pasado han sido sometidos a un gran impacto ambiental por aterramientos y drenes artificiales con objeto de sanear la zona de cara a futuras urbanizaciones. En las décadas anteriores se ha llevado a cabo la recuperación morfológica de estos hábitats singulares y muy alterados, pero en estos momentos la prioridad en los programas de gestión es la recuperación en la cobertura original de las especies estructurales, fundamentales para el funcionamiento de los saladares, como también en la conservación y reintroducción de las especies endémicas o raras, anteriormente presentes en la zona. En este sentido se requiere ampliar el conocimiento sobre las especies vegetales de saladar, en particular sobre las menos conocidas y de escasa presencia. Las especies seleccionadas para este proyecto son endemismos que pertenecen al género Limonium. Los niveles de tolerancia al estrés abiótico de las diversas especies de Limonium difieren, algunas aguantado condiciones de mayor salinidad y/o estrés hídrico. La tolerancia al estrés abiótico es un factor fundamental en la distribución de las especies y por este motivo su conocimiento es un primer paso en los programas de reintroducción de especies en los saladares. Objetivos: Para este proyecto se han seleccionado varias especies endémicas del género Limonium, con origen en diferentes saladares de la Comunidad Valenciana. Los objetivos de este proyecto son los siguientes: 1) caracterización del medio físico en las zonas de muestreo de las semillas 2) caracterización de las comunidades vegetales presentes 3) comprobación de la capacidad germinativa de las semillas en diferentes condiciones 4) crecimiento de las plantas en invernadero en distintas condiciones de estrés abiótico 5) análisis de las respuestas de las plantas al estrés 6) Metodología de trabajo: 1) Estudio de campo y c

Artículo 473, Dittrichia viscosa is a Mediterranean ruderal species that over the last decades has expanded into new habitats, including coastal salt marshes, ecosystems that are per se fragile and threatened by human activities. To assess the potential risk that this native-invasive species represents for the genuine salt marsh vegetation, we compared its distribution with that of Inula crithmoides, a taxonomically related halophyte, in three salt marshes located in La Albufera Natural Park, near the city of Valencia (East Spain). The presence of D. viscosa was restricted to areas of low and moderate salinity, while I. crithmoides was also present in the most saline zones of the salt marshes. Analyses of the responses of the two species to salt and water stress treatments in controlled experiments revealed that both activate the same physiological stress tolerance mechanisms, based essentially on the transport of toxic ions to the leaves where they are presumably compartmentalized in vacuoles and the accumulation of specific osmolytes for osmotic adjustment. The two species differ in the efficiency of those mechanisms: salt-induced increases in Na+ and Cl- contents were higher in I. crithmoides than in D. viscosa, and the osmolytes (especially glycine betaine, but also arabinose, fructose and glucose) accumulated at higher levels in the former species. This explains the (slightly) higher stress tolerance of I. crithmoides, as compared to D. viscosa, established from growth inhibition measurements and their distribution in nature. The possible activation of K+ transport to the leaves under high salinity conditions may also contribute to salt tolerance in I. crithmoides. Oxidative stress level estimated from malondialdehyde accumulation was higher in the less tolerant D. viscosa, which consequently activated antioxidant responses as a defense mechanism against stress; these responses were weaker or absent in the more tolerant I. crithmoides. Based on these results, we concluded th

[EN] Enzymatic activity and soluble protein content in relation to salt stress tolerance were investigated in Calendula officinalis seedlings after 24 days of treatment with different salt treatments, including NaCl, CaCl2, MgCl2 and mixtures of them. The marigold seedlings were used in order to investigate the possible salt-inducible responses and the possible alleviative role of calcium and magnesium salts in respect with adverse salinity conditions. Activity of superoxide dismutase (SOD; EC 1.15.1.1) and peroxidase (POD; EC 1.11.1.7) generally slightly decreased under salt treatments, with minor variations from the value recorded for control series and within applied treatments. Catalase (CAT; EC 1.11.1.6) activity was stimulated by NaCl salinity and MgCl2 addition; its activity was found to be lowest under calcium and magnesium chloride treatments solely

Comparative studies on the responses to salt stress of taxonomically related taxa should help to elucidate relevant mechanisms of stress tolerance in plants. We have applied this strategy to three Plantago species adapted to different natural habitats, P. crassifolia and P. coronopus both halophytes and P. major, considered as salt-sensitive since it is never found in natural saline habitats. Growth inhibition measurements in controlled salt treatments indicated, however, that P. major is quite resistant to salt stress, although less than its halophytic congeners. The contents of monovalent ions and specific osmolytes were determined in plant leaves after four-week salt treatments. Salt-treated plants of the three taxa accumulated Na+ and Cl- in response to increasing external NaCl concentrations, to a lesser extent in P. major than in the halophytes; the latter species also showed higher ion contents in the non-stressed plants. In the halophytes, K+ concentration decreased at moderate salinity levels, to increase again under high salt conditions, whereas in P. major K+ contents were reduced only above 400 mM NaCl. Sorbitol contents augmented in all plants, roughly in parallel with increasing salinity, but the relative increments and the absolute values reached did not differ much in the three taxa. On the contrary, a strong (relative) accumulation of proline in response to high salt concentrations (600 800 mM NaCl) was observed in the halophytes, but not in P. major. These results indicate that the responses to salt stress triggered specifically in the halophytes, and therefore the most relevant for tolerance in the genus Plantago are: a higher efficiency in the transport of toxic ions to the leaves, the capacity to use inorganic ions as osmotica, even under low salinity conditions, and the activation, in response to very high salt concentrations, of proline accumulation and K+ transport to the leaves of the plants.

[EN] Drought is one of the major causes of reduction of crop yields worldwide, a problem that will increase in the next decades due to climate change. We describe here an initial attempt to define biochemical markers associated to water stress in several hazelnut cultivars, by measuring the levels of common osmolytes and the generation of secondary oxidative stress, in plants subjected to water stress, and after recovery from the stress treatment. Proline (Pro) appears to be a reliable marker in this species, as its accumulation in leaves correlates well with the degree of stress affecting the plants. Differences between cultivars in relative Pro accumulation and oxidative stress suggested that some cultivars are more tolerant than others and could be selected for cultivation in drought-affected areas.

[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 Juncus

[EN] The negative effects of environmental stress factors on plant distribution and survival are increasing due to climate change and anthropogenic activities. We have analysed some responses to abiotic stress in Ligularia sibirica, a postglacial relict that is critically endangered in Europe. L. sibirica seedlings were subjected to water or salt stress treatments in the greenhouse. After the treatments, plant material was harvested and several growth parameters were measured; leaf contents of common osmolytes, the degree of oxidative stress affecting the plants and the level of antioxidant phenolic compounds were also determined. Both, drought and, especially, salt stress had a negative effect on the growth of L. sibirica plants. Treated plants showed an increase in proline (Pro) and total soluble sugars (TSS) levels, stronger under salt stress. Malondialdehyde (MDA, an oxidative stress biomarker) contents almost doubled, and antioxidant phenolics increased significantly in salt-stressed, but not in water-stressed plants. Pro accumulation can be used as a salt and drought stress biomarker in L. sibirica and, together with TSS, likely contributes to osmotic adjustment under stress. Increase of antioxidant phenolics appears to partly compensate the salt-induced generation of oxidative stress

[EN] mulation, activation of antioxidant systems), have been studied in Nerium oleander, a xerophytic species widely used as ornamental. Salt strongly inhibited growth, but the plants survived one month in the presence of 800 mM NaCl, indicating that the species is also relatively resistant to salt stress. Salt induced a slight increase in the levels of proline, glycine betaine and soluble sugars; the latter compounds showed much higher absolute contents, suggesting a functional role in osmotic adjustment, and the presence of constitutive mechanisms of response to salt stress. High salinity generated oxidative stress in the plants, as shown by the increase of malondialdehyde levels. Antioxidant systems, enzymatic and

[EN] Drought and salinity are the most adverse environmental factors affecting crop productivity worldwide. The increasing scarcity of fresh, high-quality irrigation water is forcing the use of alternative water sources-such as sewage, waste water or brackish water in agriculture, in general, and also in floriculture. Seed germination is the first and the most important stage in a plant s life cycle, but it is also the most sensitive to environmental conditions, representing a bottleneck in plant development. Checking for stress tolerance at the germination stage is a reliable approach for the rapid screening of a large number of plant cultivars. The aim of the present study was to analyze the responses to osmotic and ionic stress, induced by isotonic solutions of polyethylene glycol (PEG) and NaCl, in 13 cultivars of Tagetes patula, T. tenuifolia, and T. erecta at the germination stage. Germination percentages and rates, and radicle, hypocotyls, and cotyledon lengths were determined after seven days of treatment. Responses to osmotic stress induced by PEG were similar in all selected cultivars, but significant differences were detected upon the salt treatments. In general, T. erecta responded better to salt stress than the other two species, but a large variability among cultivars within each species was observed. The most stress-tolerant cultivars of T. patula were Orion and Robuszta , and those of T. tenuifolia were Luna Gold , Luna Rot and Luna Orange .

[EN] The anatomic structure of roots and culms of two Juncus species with different degrees of salt tolerance was analysed in plants grown for two months under salt stress (NaCl treatments) and in control, non-treated plants. The aim of the study was not only to compare the anatomical structures of a halophyte (J. acutus) and a related glycophyte (J. articulatus), but mostly to assess whether salt stress induced anatomical modifications, by identifying differences between control and treated plants. Several slight differences have been indeed detected, in terms of endodermis type, development of aerenchyma and extent of sclerenchyma in perivascular sheaths. The role of Casparian endodermis was here discussed in relation to its complex implications in controlling salt influx at the root level that is an efficient mechanism involved in halophytes. Aerenchyma is a common feature found in marshy halophytes, allowing them to survive naturally under flooding conditions; however, when occurring in non-waterlogged plants, as is the case of this study, it should be regarded as a genetically, constitutive adaptation rather than an inducible one. Nevertheless, such anatomic modifications should be regarded as mere alterations due to stress that is, as stress responses and not as truly adaptations to salinity. In this context, the nature of these modifications either considered as adaptations or damage indicators of salt stress should be further reconsidered.

Adverse environmental conditions limit crop yield and better understanding of plant response to stress will assist the development of more tolerant cultivars. Maize and common bean plantlets were evaluated under salinity, high temperature, drought and waterlogged conditions to identify biochemical markers which could be useful for rapid identification of putative stress tolerant plants. The levels of phenolics (free, cell wall-linked, total), aldehydes including malondialdehyde and chlorophylls (a, b, total) were measured on stressed plantlets. Only two indicators were statistically non-significant: chlorophyll b in maize plantlets stressed with sodium chloride and malondialdehyde content in drought stressed maize. The most remarkable effects of abiotic stresses can be summarized as follows: (i) salinity increased levels of free phenolics in maize plantlets and chlorophylls (a, b, total) in common bean; (ii) high temperature (40 °C) elevated levels of chlorophylls (a, b, total) in maize but decreased chlorophylls (a, b, total) and free phenolics in common bean; (iii) drought increased phenolics and decreased chlorophylls (a, b, total) in maize and increased chlorophyll pigments (a, b, total) in common bean; (iv) waterlogging increased free phenolics and decreased chlorophylls (a, b, total) in maize and increased chlorophyll (a, total) in common bean. Free phenolics and chlorophylls, especially a, were the most responsive indicators to stress and can, therefore, be considered putative biochemical markers for abiotic stress tolerance in maize and common bean. The use of Fisher s linear discriminant analysis to differentiate non-stressed and stressed plants in breeding programs is also a novel aspect of this report. Fisher s linear discriminant functions classified correctly 100% of non-stressed or stressed originally grouped plants.

The effects of salt and water stress on growth and several stress markers were investigated in cherry tomato plants. Some growth parameters (stem length and number of leaves) and chlorophyll contents were determined every third day during plant growth, and leaf material was collected after 25 and 33 days of treatment. Both stresses inhibited plant growth; chlorophyll levels, however, decreased only in response to high NaCl concentrations. Proline contents largely increased in leaves of stressed plants, reaching levels high enough to play a major role in cellular osmotic adjustment. Despite reports indicating that tomato does not synthesize glycine betaine, the stress-induced accumulation of this osmolyte was detected in cherry tomato, albeit at lower concentration than that of proline. Therefore, it appears that the plants are able to synthesise glycine betaine as a secondary osmolyte under strong stress conditions. Total sugars levels, on the contrary, decreased in stress-treated plants. Both stress treatments caused secondary oxidative stress in the plants, as indicated by a significant increase in malondialdehyde (MDA) contents. Water stress led to an increase in total phenolics and flavonoid contents and a reduction of carotenoid levels in the leaves; flavonoids also increased under high salinity conditions.

[EN] We have determined the relative tolerance to osmotic/ionic stress of three Portulaca species (P. halimoides, P. grandiflora and P. oleracea) at the seed germination and early seedling development stage. The three species are relatively resistant to stress, although at high concentrations NaCl strongly inhibited germination, whereas at the same osmotic potential PEG did not. Seedling growth was more clearly inhibited, in a concentration-dependent manner, with salt stress showing again a relatively stronger effect. Our data indicate that P. oleracea is the most salt-tolerant of the tested species and therefore the most promising candidate for saline agriculture , to be cultivated using low-quality, saline water for irrigation

[EN] We have isolated full-length cDNA clones of the NHX1 gene – encoding the vacuolar Na+ /H+ antiporter – from three Plantago species (P. crassifolia, P. coronopus and P. major) differing in salt tolerance. A phylogenetic tree of their deduced protein sequences and those of NHX1 antiporters previously isolated from other species suggested the presence of some structural features characteristic of the proteins of salt tolerant taxa. The expression patterns of the NHX1 genes in the presence of salt correlated with the relative degree of salt tolerance of the three species: no induction was detected in the least tolerant P. major – and in the glycophyte A. thaliana – and the highest and quickest induction was observed in the most tolerant P. crassifolia. These data support the hypothesis that the NHX1 antiporters play a functional role in the mechanisms of salt tolerance in plants.

The Norway spruce (Picea abies), the most important tree species in European forests, is relatively sensitive to salt and does not grow in natural saline environments. Yet many trees are actually exposed to salt stress due to the common practice of de-icing of mountain roads in winter, using large amounts of NaCl. To help develop strategies for an appropriate use of reproductive seed material on reforestation sites, ensuring better chances of seedling survival in salt-affected areas, we have studied the responses of young spruce seedlings to salt treatments. The specific aim of the work was to identify the optimal salt stress biomarkers in Picea abies, using as experimental material seedlings obtained by germination of seeds with origin in seven populations from the Romanian Carpathian Mountains. These responses included general, conserved reactions such as the accumulation of ions and different osmolytes in the seedlings needles, reduction in photosynthetic pigments levels, or activation of antioxidant systems. Although changes in the contents of different compounds involved in these reactions can be associated to the degree of stress affecting the plants, we propose that the (decreasing) levels of total phenolics or total carotenoids and the (increasing) levels of Na+ or K+ ions in Picea abies needles, should be considered as the most reliable and useful biomarkers for salt stress in this species. They all show very high correlation with the intensity of salt stress, independently of the genetic background of the seeds parental population, and relatively easy, quantitative assays are available to determine their concentrations, requiring simple equipment and little amount of plant material.

Inula crithmoides es una especie halófila, característica de las zonas de saladar mediterráneas. Dittrichia viscosa es una especie emparentada, de la misma familia Asteraceae, muy frecuente en zonas antropizadas y, aunque autóctona, considerada con potencial invasor. En el presente TFG se realizará un estudio de germinación de semillas recolectadas en una mallada de la Devesa del Saler (Valencia) y crecimiento de las plantas en condiciones de estrés salino e hídrico. Después de establecer un protocolo para la óptima germinación de las semillas, se efectuarán ensayos de germinación en concentraciones crecientes de cloruro sódico (NaCl) y en presencia de polietilenglicol (PEG) en concentraciones iso-osmóticas. Las respuestas a estrés en la fase de crecimiento se comprobarán en plantas obtenidas a partir de semillas sembradas directamente sobre un sustrato de turba y vermiculita y tratadas con diferentes concentraciones de NaCl o sometidas a estrés hídrico por la ausencia de riego. Una vez obtenidos todos los resultados podemos concluir que Dittrichia viscosa no representa un peligro real para las halofitás típicas de los saladares de nuestra zona porque en condiciones de elevado estrés ambiental (salino o hídrico) se desarrolla con mayores dificultades ya que es menos competitiva que una halófita típica como es Inula Crithmoides., Inula crithmoides is a halophyte species characteristic of Mediterranean salt marsh areas. Dittrichia viscosa is very common in anthropic areas and, although is a native related species of the same family Asteraceae, it is considered as potentially invasive. In the present final work project were analyzed germination of seeds collected in the wild from a salt masrh at Devesa El Saler (Valencia) in the presence of sodium chloride (NaCl) and polyethylene glycol (PEG) in iso-osmotic concentrations. Plant growth under saline conditions and water stress was also investigated here. The responses to stress in the growth phase were checked in plants obtained from seeds sown directly onto a substrate of peat and vermiculite and treated with different concentrations of NaCl or water-stressed by a lack of irrigation. Once we obtained all the results we can conclude that viscous Dittrichia viscosa is not a real danger to the typical halophytes plants salt marshes in our area because under high environmental stress (saline or water) develops with greater difficulties as it is less competitive than the real halophylous species Inula crithmoides.

Salt stress, as well as other abiotic stresses, induces the activation of antioxidant systems in plants, since they cause oxidative stress as a secondary effect. We have analysed the antioxidant response to salt treatments of two related species, Inula crithmoides and Dittrichia viscosa, in terms of accumulation of total phenolic compounds and flavonoids. The most salt-tolerant species, I. crithmoides, was less affected than D. viscosa by oxidative stress in the presence of high NaCl concentrations, as revealed by its relatively lower contents of malondialdehyde, a reliable oxidative stress biomarker. Consequently, salt-induced accumulation of antioxidant phenolics and flavonoids was much lower in I. crithomoides, as compared to D. viscosa. From these data, we concluded that the higher salt tolerance of I. crithomoides cannot be based in the activation of stronger antioxidant systems, but must be due to other stress responses such as the control of water and ion transport and the synthesis of osmolytes for cellular osmotic balance

The final publication is available at Springer via http://dx.doi.org/10.1007/s11104-014-2218-2, Aims Responses to salt stress of two Gypsophila species that share territory, but with different ecological optima and distribution ranges, were analysed. G. struthium is a regionally dominant Iberian endemic gypsophyte, whereas G. tomentosa is a narrow endemic reported as halophyte. Theworking hypothesis is that salt tolerance shapes the presence of these species in their specific habitats. Methods Taking a multidisciplinary approach, we assessed the soil characteristics and vegetation structure at the sampling site, seed germination and seedling development, growth and flowering, synthesis of proline and cation accumulation under artificial conditions of increasing salt stress and effect of PEG on germination and seedling development. Results Soil salinity was low at the all sampling points where the two species grow, but moisture was higher in the area of G. tomentosa. Differences were found in the species salt and drought tolerance. The different parameters tested did not show a clear pattern indicating the main role of salt tolerance in plant distribution. Conclusions G. tomentosa cannot be considered a true halophyte as previously reported because it is unable to complete its life cycle under salinity. The presence of G. tomentosa in habitats bordering salt marshes is a strategy to avoid plant competition and extreme water stress

[EN] Salt stress responses were studied in three Plantago species (P. crassifolia, P. coronopus and P. major), with different levels of salt stress tolerance, at growth and reproductive stages of the life cycle. Plants were treated with increasing salt concentrations (0, 100, 200 and 400 mM NaCl) under controlled conditions in the greenhouse. Fresh biomass, leaf length and reproductive parameters related to flowering were analysed. To evaluate the reproductive success of salt-stressed plants, seeds produced after two months of treatment were sampled, and the mean number of seeds per plant and mean seed weight per treatment were determined. Seeds were germinated in vitro and seed and seedling quality were assessed by determining germination percentages and rates, length of radicle, hypocotyl, cotyledon leaves, and the angle of cotyledonary leaves. The seedling vigour index was also calculated. Vegetative (fresh weight and leaf length) and reproductive traits (number of inflorescences, scape and spike length, mean number of seeds per spike and mean seed weight) were less affected by salinity in the more stress tolerant species P. crassifolia and P. coronopus than in P. major. Rate and velocity of germination of seeds produced by plants grown under saline treatments were similar in all species; however seedling development was less successful in P. major, as shown by length of the radicle, hypocotyl and cotyledonary leaves. The relative sensitivity to salt of the investigated Plantago species correlated with their distribution in nature: P. major, never present in saline environments, was much more affected by salt than its halophytic counterparts, while P. crassifolia, which grows in saline habitats, exhibited the most efficient responses to salt stress, especially at the early seedling development stage

[EN] Drought is the most important single environmental stress factor that reduces crop yields worldwide. In the context of global climate change, selection and/or development of drought-resistant varieties of cultivated plants is becoming an urgent need for agriculture in arid and semiarid regions. In this work we have analysed physiological (growth inhibition) and biochemical (proline levels) responses to water stress of 5 cultivars of Tagetes patula and 5 cultivars of T. tenuifolia. The most drought-tolerant cultivars were found to be Bolero in T. patula and Luna gold in T. tenuifolia, while Orion and Luna orange were the most sensitive for each species

In their natural habitats, different mechanisms may contribute to the tolerance of halophytes to high soil salinity and other abiotic stresses, but their relative contribution and ecological relevance, for a given species, remain largely unknown. We studied the responses to changing environmental conditions of five halophytes (Sarcocornia fruticosa, Inula crithmoides, Plantago crassifolia, Juncus maritimus and J. acutus) in a Mediterranean salt marsh, from summer 2009 to autumn 2010. A principal component analysis was used to correlate soil and climatic data with changes in the plants contents of chemical markers associated with stress responses: ions, osmolytes, malondialdehyde (MDA, a marker of oxidative stress) and antioxidant systems. Stress tolerance in S. fruticosa, I. crithmoides and P. crassifolia (all succulent dicots) seemed to depend mostly on the transport of ions to aerial parts and the biosynthesis of specific osmolytes, whereas both Juncus species (monocots)were able to avoid accumulation of toxic ions, maintaining relatively high K+/Na+ ratios. For the most salt-tolerant taxa (S. fruticosa and I. crithmoides), seasonal variations of Na+, Cl2, K+ and glycine betaine, their major osmolyte, did not correlate with environmental parameters associated with salt or water stress, suggesting that their tolerance mechanisms are constitutive and relatively independent of external conditions, although they could be mediated by changes in the subcellular compartmentalization of ions and compatible osmolytes. Proline levels were too low in all the species to possibly have any effect on osmotic adjustment. However except for P. crassifolia proline may play a role in stress tolerance based on its osmoprotectant functions. No correlation was observed between the degree of environmental stress and the levels of MDA or enzymatic and non-enzymatic antioxidants, indicating that the investigated halophytes are not subjected to oxidative stress under natural conditions and

[EN] A general response of plants to high soil salinity relies on the cellular accumulation of osmolytes, which help the plant to maintain osmotic balance under salt stress condition and/or act as osmoprotectants with chaperon or reactive oxygen species (ROS) scavenging activities. Yet the ecological relevance of this response for the salt tolerance mechanisms of halophytes in their natural habitats remains largely unknown. In this review, we describe and discuss published data supporting the participation of compatible solutes in those mechanisms, with especial focus on soluble carbohydrates. Evidence for a functional role of carbohydrates in salt tolerance include: (i) relatively high levels of specific sugars and polyols have been detected in many halophytic taxa; (ii) an increase in salt tolerance has often been observed in parallel with increased intracellular levels of particular soluble carbohydrates, in transgenic plants overexpressing the corresponding biosynthetic enzymes; (iii) there are several examples of genes involved in carbohydrate metabolism which are induced under salt stress conditions; (iv) specific sugars or polyols have been shown to accumulate in different halophytes upon controlled salt treatments; and (v) although very few field studies on environmentally induced carbohydrate changes in halophytes exist, in general they also support the involvement of this type of osmolytes in salt stress tolerance mechanisms. We also highlight the complexities of unequivocally attributing carbohydrates a biological role in salt tolerance mechanisms of a given tolerant species. It is proposed that research on halophytes in their natural ecosystems should be intensified, correlating seasonal changes in carbohydrate contents with the degree of environmental stress affecting the plants. This could be an important complement to experiments made under more controlled (but artificial) conditions, such as laboratory set-ups.

Accumulation of compatible solutes or osmolytes is a general response of plants to abiotic stress conditions, but we still have very limited knowledge on the relevance of this response for stress tolerance mechanisms of a given tolerant species. We have determined the levels of common osmolytes (proline, glycine betaine and total soluble sugars) in three Juncus species, two salt tolerant (J. acutus and J. maritimus) and one salt-sensitive (J. articulatus), subjected to salt or water stress treatments. Correlation of the patterns of osmolyte accumulation with salt tolerance of the three taxa, indicated that biosynthesis of Pro (but not the increase of glycine betaine or sugar contents) plays a relevant role in the stress tolerance of the analysed Juncus species

[CA] Les previsions de canvi climàtic mostren un agreujament de les condicions d'estrès salí, donant lloc a la inevitable pèrdua de biodiversitat i de producció agrícola, sent la regió Mediterrània una de les més amenaçades. El coneixement dels mecanismes de tolerància en les plantes halòfiles pot ajudar a comprendre la supervivència d'aquestes plantes en les dures condicions del seu entorn natural i a elaborar estratègies de recuperació, conservació i cultiu com a anticipació a la imparable desertització i augment de sòls afectats per la salinitat. Per a aquest projecte s'han escollit dues espècies de plantes halòfiles crasses Plantago crassifolia Forssk. i Inula crithmoides L. Per una banda s'ha analitzat la influència de la salinitat en el creixement d'aquestes espècies en condicions controlades de cultiu en càmera i per una altra l'acumulació de prolina i glicina betaïna tant en condicions controlades com naturals. L'evolució del creixement en ambdues plantes es correlacionà amb la seua ecologia. Els nivells de prolina en ambdues espècies, resultaren baixos en condicions de camp, no obstant en condicions controlades la síntesi de prolina s'incrementà amb els tractaments de NaCl de majors concentracions (450 mM i 600 mM). Els nivells de glicina betaïna per a P. crassifolia foren reduïts i mostraren de nou un increment quan es va sotmetre la planta a concentracions de NaCl elevades. En canvi, en I. crithmoides aquestos nivells resultaren suficientment elevats en ambdós casos com per a actuar com a osmolit principal. ABSTRACT, [EN] Predictions of climate change are worsening the conditions of salt stress, resulting in an inevitable loss of biodiversity and agricultural production, being the Mediterranean one of the most threatened regions of world. Knowing the mechanisms of tolerance in halophytic plants may help to understand the survival of these plants in the harsh conditions of their natural environment and to propose strategies for recovery, conservation and cultivation as an anticipation of the unstoppable desertification and the increase of soils affected by salinity. Two halophytic succulent plant species, Plantago crassifolia Forssk. and Inula crithmoidesL. were chosen for this project. The influence of salinity on the growth of these species under controlled cultivation chamber was analyzed. Moreover, the accumulation of proline and glycine betaine were analyzed in both controlled and natural conditions. The evolution of growth in both plants was correlated with their ecology. Proline levels in both species were low in field conditions, but under controlled conditions the synthesis of proline increased with higher concentrations of NaCl (450 mM and 600 mM). The levels of glycine betaine for P. crassifolia were low and showed an increase only when plants were subjected to higher NaCl concentrations. In contrast, levels of glycine betaine in I. crithmoides were sufficiently high in both cases to act as principal osmolyte

[EN] We have studied whether two common osmolytes proline (Pro) and glycine betaine (GB) accumulate in plants of different Plantago species in response to salt and water stress, which would suggest that these compatible solutes and osmoprotectants fulfil a functional role of in the plants stress tolerance mechanisms. Plants of P. coronopus, P. major, P. crassifolia and P. lagopus were treated with increasing NaCl concentrations or subjected to water stress, under controlled conditions in the greenhouse. GB and Pro contents in control, non-stressed plants were relatively low and, in most cases, did not change, or increased only moderately when the plants were maintained without water or were grown in the presence of up to 400 mM NaCl, for four weeks. However, higher salt concentrations (450 600 mM NaCl), which these taxa never encounter in their natural habitats, induced a significant accumulation of Pro in all species but P. major, the most salt-sensitive one. These data indicate that GB and Pro do not act as functional osmolytes in Plantago species, and do not contribute to osmotic adjustment under natural conditions; however, these plants have the potential to activate Pro-mediated mechanisms of salt tolerance at very high, artificial salinity levels

The patterns of ion uptake were analysed in three dicotyledonous (Arthrocnemum macrostachyum, Sarcocornia fruticosa and Inula crithmoides) and two monocotyledonous (Juncus acutus and J. maritimus) halophytes, collected from a salt marsh in SE Spain. The experimental design included four plots in different positions within the marsh, and three sampling periods corresponding to spring, summer and autumn 2011. Electric conductivity, pH, and Na+, K+, Ca2+, Mg2+ and Cl- contents were determined in saturated soil extracts. In plants, the same ions were extracted in boiling water. In soil samples, spatial variation in the measured parameters among plots was higher than the seasonal variation within plots, whereas in plants significant differences in ion contents were detected only between species, but not between plots or sampling seasons for a given species. The dicot species under study are Na+ and Cl- accumulators, showing significant higher levels of these ions than the monocot taxa, but a direct correlation between ion content in soil and plants could be not established

Lipases are useful enzymes that are responsible for the hydrolysis of triacylglycerides and play an important role in plant growth. In this study, we report a rapid molecular method to amplify a partial sequence of the lipase class 3 family designated BnLIP3 gene of Brassica napus L. in order to follow its expression and analyze its role during seed germination. Therefore, we conceived PCR homologous primers to amplify the active site encoding region of the BnLIP3 family genes. Subsequently, to sequence determination of the 582 bp fragment, we deduced BnLIP3 specific primers for a nested RTPCR application. The deduced 194 amino acid sequence (Genbank 1160264) was found to share 85% of identity with lipase from Arabidopsis thaliana class 3 family. The GxSxG consensus motif near the catalytic triad at the active serine site was also identified. The peptidic sequence showed little homology with mammalian and microbial lipases. RT-PCR analysis indicated that BnLIP3 gene was expressed during B. napus seed germination.

Soil salinisation is an increasing problem for agriculture, affecting the most productive crop areas in the world those cultivated under irrigation in arid and semi-arid regions. In addition, a significant fraction of the world's land surface is naturally saline and is not available for agriculture. Cultivation of these salinised areas, if possible, would contribute to the increase in food production needed in the next few decades to feed a growing world population. Unfortunately, our present crops are all salt-sensitive, to a greater or lesser degree, and classical breeding has not succeeded in improving their resistance to salinity. Similarly, genetic engineering approaches have not yet delivered commercial salt-tolerant 'biotech' (GM) crops. Yet a small percentage (ca. 0.25%) of wild angiosperm species halophytes are adapted to saline soils in their natural habitats, and many are able to complete their life cycle at salinity levels similar to, or even higher than sea water. Halophytes could be cultivated in salinised land already lost for agriculture, and also in naturally saline, marginal soils, using brackish water, reclaimed industrial/urban waste water, or even sea water for irrigation. Most important, this 'saline agriculture' will not compete with conventional crops for increasingly scarce resources, such as fertile land and good-quality irrigation water. Several salt-tolerant taxa are being investigated as potential 'new' halophytic crops and others can be developed in the near future, to be used, for example: i) as human food or for animal feed; ii) for production of biofuels: biomass generation for bioethanol, and biodiesel obtained from oleaginous seeds; iii) for the production of secondary metabolites with medical, nutraceutical, cosmetic or other industrial applications; iv) as new ornamental plants, for gardening and landscape architecture. As the crop potential of many of these species is unknown and some may have undesirable agronomic characteristi

[EN] In Plantago crassifolia, a moderate halophyte characteristic of borders of salt marshes in the Mediterranean region, reproductive development is more sensitive to high soil salinity than vegetative growth. To investigate the possible role of calcium and magnesium salts in the responses of this species to salt stress, adult plants were submitted over a 2-month period to treatments with 300 mM NaCl-a concentration which affects, but does not completely inhibit seed formation in P. crassifolia-either alone or combined with low concentrations of CaCl2 (10 mM) or MgCl2 (20 mM). The NaCl treatment did not affect plant vegetative growth and had a stimulating effect on flowering. Yet almost half the spikes produced had aborted seeds, and the effect on seed number and quality-estimated by their mean weight and germination capacity-was obviously deleterious. Addition of calcium or magnesium chloride during the salt-stress treatment completely counteracted the negative effect of NaCl on the reproductive success of the plants: the number, weight and germination frequency of the seeds were similar to that in the control, non-stressed plants. These results indicate that both divalent cations can suppress or mitigate the deleterious effects of salt stress. While this protective role is well established in the case of calcium, we provide here the first experimental evidence of a similar function for magnesium.