Responses of evergreen and deciduous Quercus species to enhanced ozone levels

Plants of one evergreen oak (Quercus ilex) and three deciduous oaks (Q. faginea, with small leaves; Q. pyrenaica and Q. robur, with large leaves) were exposed both to filtered air and to enhanced ozone levels in Open-Top Chambers. Q. faginea and Q. pyrenaica were studied for the first time. Based on visible injury, gas exchange, chlorophyll content and biomass responses, Q. pyrenaica was the most sensitive species, and Q. ilex was the most tolerant, followed by Q. faginea. Functional leaf traits of the species were related to differences in sensitivity, while accumulated ozone flux via stomata (POD1.6) partly contributed to the observed differences. For risk assessment of Mediterranean vegetation, the diversity of responses detected in this study should be taken into account, applying appropriate critical levels. © 2010 Elsevier Ltd. All rights reserved.We thank both the Ministerio de Medio Ambiente y Medio Rural y Maritimo (in collaboration with ICP-Forests), and the Conselleria de Medi Ambient, Aigua i Habitatge and Interreg III (ForMedOzone and VegetPollOzone projects) for supporting the OTC activity. Institut Universitario CEAM-UMH is also supported by Generalitat Valenciana and Fundacion Bancaja, benefiting from CONSOLIDER-INGENIO 2010 (GRACCIE) and Prometeo (Generalitat Valenciana) Programs. Filippo Bussotti and two anonymous referees are thanked for their useful comments. Carmen Martin is also thanked for taking care of the plants.Calatayud, V.; Cervero, J.; Calvo, E.; García Breijo, FJ.; Reig Armiñana, J.; Sanz, M. (2011). Responses of evergreen and deciduous Quercus species to enhanced ozone levels. Environmental Pollution. 159(1):55-63. doi:10.1016/j.envpol.2010.09.024S5563159

Physiological,anatomical and biomass partitioning responses to ozone in the Mediterranean endemic plant Lamottea dianae

Ozone effects on the perennial forb Lamottea dianae were studied in an open-top chamber experiment. Ozone was found to induce reductions in CO 2 assimilation and water use efficiency in the leaves of this species. These reductions were mainly related to a decline in the in vivo CO 2 fixation capacity of Rubisco (V c,max), rather than to stomatal limitations or photoinhibitory damage (F v:F m). In addition to chloroplast degeneration, other observed effects were callose accumulation, formation of pectinaceous wart-like cell wall exudates and phloem alterations. Moreover, ozone exposure significantly reduced root dry biomass. The possible relevance of these adverse effects for Mediterranean forbs is commented. These results show that endemic plants can be very sensitive to ozone, suggesting that risks associated with this pollutant should be taken into account for conservation purposes. © 2011 Elsevier Inc.We thank the Conselleria de Medi Ambient, Aigua, territory i Habitatge and FEDER funds (project VegetPollOzone, Interreg IIIb, Meddoc) for supporting parts of this study. The Instituto Universitario CEAM-UMH is partly supported by Generalitat Valenciana, Fundacion Bancaja, and benefits form the projects CONSOLIDER-INGENIO 2010 (GRACCIE) and Prometeo Program (Generalitat Valenciana). Emilio Laguna and Mari Carmen Escriva are also thanked for providing us the plants and, together with Joan Perez, for their comments on aspects of the biology of this species. Carmen Martin is thanked for taking care of the plants. Four anonymous referees provided very useful comments for improving the manuscript.Calatayud, V.; García Breijo, FJ.; Cervero, J.; Reig Armiñana, J.; Sanz Sánchez, MJ. (2011). Physiological,anatomical and biomass partitioning responses to ozone in the Mediterranean endemic plant Lamottea dianae. Ecotoxicology and Environmental Safety. 74(5):1131-1138. doi:10.1016/j.ecoenv.2011.02.023S1131113874

Effets anatomiques de l'ozone sur le térébinthe (Pistacia terebinthus)

Cet article, écrit par des chercheurs espagnols de Valence, décrit les changements anatomiques produits sur les feuilles de térébinthe, arbuste méditerranéen, soumises à différents niveaux d'exposition à l'ozone. On note une grande variabilité de réactions en fonction du stade de développement. Ainsi, des expositions à l'ozone effectuées sur différentes années peuvent produire des lésions visibles, pour des doses d'ozone très différentes

Dommages forestiers et pollution à l'ozone dans les réserves naturelles : le cas de l'arolle dans le sud-est de la France -

En région méditerranéenne, dans le Sud-Est de la France, de fortes concentrations en ozone sont mesurées depuis de nombreuses années et les valeurs d'AOT 40 dépassent régulièrement les seuils européens de protection de la végétation et de la forêt. Parallèlement, des symptômes d'ozone spécifiques (mottling) ont été observés sur les aiguilles des conifères, en particulier sur l'arolle (Pinus cembra) entre 2006 et 2008. Une corrélation entre les atteintes spécifiques sur les aiguilles âgées d'un et deux ans et les concentrations en ozone a été mise en évidence. Certains échantillons foliaires, reproduits en chambre de fumigation, ont été soumis à une analyse microscopique pour évaluer l'impact de l'ozone au niveau cellulaire. Une étude de dispersion des oxydes d'azote a été réalisée dans le département des Alpes-Maritimes afin d'expliquer l'origine de l'ozone mesurée en altitud

Morphology, anatomy and germination response of heteromorphic achenes of Anthemis chrysantha J. Gay (Asteraceae), a critically endangered species

[EN] This study demonstrates that Anthemis chrysantha, a 'Critically Endangered' annual plant, produces two morphs of achenes: white and dark achenes, which differ in size, mass, anatomy and germination behaviour. Fresh white achenes germinated at all temperatures assayed from 10 to 25 degrees C in both continuous darkness and 12-h photoperiod, ranging between 24% at 25 degrees C in darkness and 89% at 12/20 degrees C in light, whereas fresh dark achenes did not germinate under any temperature or light conditions. To identify differences in dormancy type between the two morphs, germination of dry-stored achenes, and achenes stratified at 5 or 25 degrees C for 2 months were tested in both darkness and light at 5, 15 and 12/20 degrees C for dry-stored and warm-stratified (25 degrees C) achenes; and at 15, 25 and 12/20 degrees C for cold-stratified (5 degrees C) achenes. Of the white achenes, 90% germinated during the cold stratification period. In general, dry storage and warm stratification did not increase germination compared to fresh achenes. However, dark achenes did not germinate under any conditions. Dark achene dormancy was only broken by mechanical scarification or by excising the embryo (germination reached 71%). An anatomical study showed that the mesocarp of dark achenes had no intercellular spaces and was much thicker and stronger than that of white achenes, making the entry of water difficult, and also preventing germination by mechanical restriction. This study demonstrated that dormancy in the dark achenes is likely caused by the thickness of their pericarp, physically impeding germination and hampering imbibition of water.This work was financed by the Consejeria de Agricultura y Agua de la Comunidad Autonoma de la Region de Murcia and the Fundacion Seneca de la Region de Murcia (Project 1186/PI/09).Aguado, M.; Martinez-Sanchez, JJ.; Reig Armiñana, J.; García Breijo, FJ.; Franco, JA.; Vicente, MJ. (2011). Morphology, anatomy and germination response of heteromorphic achenes of Anthemis chrysantha J. Gay (Asteraceae), a critically endangered species. Seed Science Research. 21(4):283-294. doi:10.1017/S0960258511000183S28329421

Coordinated ultrastructural and phylogenomic analyses shed light on the hidden phycobiont diversity of Trebouxia microalgae in Ramalina fraxinea

[EN] The precise boundary delineations between taxa in symbiotic associations are very important for evolutionary and ecophysiological studies. Growing evidence indicates that in many cases, the use of either morphological characters or molecular markers results in diversity underestimation. In lichen symbioses. Trebouxia is the most common genus of lichen phycobionts, however, the diversity within this genus has been poorly studied and as such there is no clear species concept. This study constitutes a multifaceted approach incorporating aspects of ultrastructural characterization by TEM and phylogenomics to evaluate the morphological and genetic diversity of phycobionts within the sexually reproducing lichen Ramalina fraxinea in the context of Mediterranean and temperate populations. Results reveal an association with at least seven different Trebouxia lineages belonging to at least two species. T. decolorans and T. jamesii, and diverse combinations of such lineages coexisting within the same thallus depending on the analysed sample. Some of these lineages are shared by several other non-related lichen taxa. Our findings indicate the existence of a highly diverse assemblage of Trebouxia algae associating with R. fraxinea and suggest a possible incipient speciation within T. decolorans rendering a number of lineages or even actual species. This study stresses the importance of coordinated ultrastructural and molecular analyses to improve estimates of diversity and reveal the coexistence of more than one Trebouxia species within the same thallus. lt is also necessary to have clearer species delimitation criteria within the genus Trebouxia and microalgae in general.This study was funded by the Ministerio de Economia y Competitividad (MINECO CGL2012-40058-0O2-01/02), FEDER, the Generalitat Valenciana (PROMETEOII2013/021, GVA) and the Direccion General de Universidades e Investigacion de la Consejeria de Educacion de la Comunidad de Madrid - Universidad de Alcala (CCG10-UAH/GEN-5904). Drs. Arantxa Matins and Patricia Moya (Universitat de Valencia) made helpful comments on the manuscript.Català, S.; Campo, ED.; Barreno, E.; García-Breijo, F.; Reig Armiñana, J.; Casano, L. (2016). Coordinated ultrastructural and phylogenomic analyses shed light on the hidden phycobiont diversity of Trebouxia microalgae in Ramalina fraxinea. Molecular Phylogenetics and Evolution. 94:765-777. https://doi.org/10.1016/j.ympev.2015.10.021S7657779

Estudio de la sensibilidad de diversas especies fungicas frente a metabolitos naturales

The existence in severa1 filamentous fungi of remarkable differences in sensitivity to certain natural metabolites with a vegetable origin has been corroborated. These differences in sensitivity can be used as markers which make possible the experimental design for the selection and analysis of hybrida released from somatic cellular fusion, so avoiding the manipulation of the genome of the original strain. Considering the quantitative and qualitative shortage of synthetic fungicides, the high inhibitory power on the bacteria1 and fungal growth of the hydroalcoholic extract of Clematis vitalba is very interesting. Furthermore, this extract is so effective as the trading goods and it presents the advantages of: (1) being thermo- stable at the autoclaving conditions and (2) acting in the watery phase; this makes easy its use in the laboratory. The possibility of its feasible usage as a commercial fungicyd can not be discarded.Se ha corroborado la existencia de marcadas diferencias de sensibilidad de varios hongos filamentosos frente a ciertos metabolitos naturales de origen vegetal. Estas distintas sensibilidades constituyen marcadores que permiten el diseno de métodos de selección y análisis de híbridos obtenidos en experiencias de fusión celular somática, evitándose así la manipulación del genoma de la cepa original para la obtención de marcadores genéticos (auxotrofías, resistencias ... imprescindibles en todos los métodos de selección utilizados hasta el momento. Dada la escasez cuantitativa y cualitativa de fungicidas de síntesis resulta interesante el alto poder inhibidor del crecimiento de bacterias y hongos presentado por el extracto hidro-alcohólico de Clematis vitalba, que además de ser comparable en eficacia a los productos comerciales, presenta la ventaja de ser termoestable en las condiciones de esterilización por autoclave y actuar en fase acuosa, lo que facilita su manejo en el laboratorio, no debiendo descartarse la posibilidad de su posible uso como fungicida comercial

Epicuticular wax content and morphology as related to ethylene and storage performance of ‘Navelate’ orange fruit

8 pages, 6 figures, 1 table. -- Available online 15 September 2009.The effect of ethylene (2 μL L−1) on total and soft epicuticular wax content and wax morphology has been investigated in mature ‘Navelate’ (Citrus sinensis, L. Osbeck) oranges held under non-stressful environmental conditions (22 °C and constant high relative humidity (90–95% RH)). In addition, the objective of the study was to understand whether the ethylene-induced changes in epicuticular wax might participate in the beneficial effect of ethylene reducing non-chilling peel pitting, by modifying peel water, osmotic or turgor potential, or disease incidence caused by Penicillium digitatum (Pers.:Fr.) Sacc. Ethylene increased total and soft epicuticular wax content in ‘Navelate’ fruit and induced structural changes in surface wax that might be related to the formation of new waxes. Changes in epicuticular wax morphology, but not in its content, might be involved in the protective role of ethylene reducing non-chilling peel pitting, although the beneficial effect of the hormone is not related to water stress. Cell water and turgor potentials in freshly harvested fruit and fruit stored in air under non-stressful conditions suggest that water stress is not a limiting factor leading to the development of this physiological disorder. In addition, the results indicated that formation of new waxes in fruit treated with ethylene may partially cover stomata, cracks or areas lacking wax occurring in stored fruit and is likely to improve physical barriers to P. digitatum penetration.This work was supported by research grant AGL2002-1727 from the Comisión Interministerial de Ciencia y Tecnología (CICYT), Spain. Cajuste was the recipient of a fellowship from the Program SUPERA, México.Peer reviewe