The appeal-to-nature fallacy : homeopathy and biodynamic agriculture in official EU regulations

There is no scientific evidence to support the affirmation that organic food is more nutritious or that its production is more sustainable than traditional food. In addition, productivity is very low and, concomitantly, the price is higher. This article reviews the basics of EU regulations on organic food production and concludes that, for the most part, they mislead the consumer and are not science based. Most of them rely on concepts related to the appeal-to-nature fallacy, with the explicit presence of pseudosciences, such as homeopathy or biodynamic agriculture. On the other hand, interesting aspects such as the carbon footprint or local production are not present in the regulations, and technological improvements that could be useful for organic food production are excluded

Should we recommend organic crop foods on the basis of health benefits? Letter to the editor regarding the article by Baranski et al

Mulet Salort, JM. (2014). Should we recommend organic crop foods on the basis of health benefits? Letter to the editor regarding the article by Baranski et al. British Journal of Nutrition. 112(10):1745-1747. doi:10.1017/S0007114514002645S1745174711210Bradbury, K. E., Balkwill, A., Spencer, E. A., Roddam, A. W., Reeves, G. K., … Pirie, K. (2014). Organic food consumption and the incidence of cancer in a large prospective study of women in the United Kingdom. British Journal of Cancer, 110(9), 2321-2326. doi:10.1038/bjc.2014.148Dangour A , Aikenhead A & Hayter A , et al. (2009) Comparison of putative health effects of organically and conventionally produced foodstuffs: a systematic review. http://multimedia.food.gov.uk/multimedia/pdfs/organicreviewreport.pdf.Dangour, A. D., Dodhia, S. K., Hayter, A., Allen, E., Lock, K., & Uauy, R. (2009). Nutritional quality of organic foods: a systematic review. The American Journal of Clinical Nutrition, 90(3), 680-685. doi:10.3945/ajcn.2009.28041Barański, M., Średnicka-Tober, D., Volakakis, N., Seal, C., Sanderson, R., Stewart, G. B., … Leifert, C. (2014). Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analyses. British Journal of Nutrition, 112(5), 794-811. doi:10.1017/s0007114514001366Tuomisto, H. L., Hodge, I. D., Riordan, P., & Macdonald, D. W. (2012). Does organic farming reduce environmental impacts? – A meta-analysis of European research. Journal of Environmental Management, 112, 309-320. doi:10.1016/j.jenvman.2012.08.018Gutteridge, J. M. C., & Halliwell, B. (2010). Antioxidants: Molecules, medicines, and myths. Biochemical and Biophysical Research Communications, 393(4), 561-564. doi:10.1016/j.bbrc.2010.02.071Seufert, V., Ramankutty, N., & Foley, J. A. (2012). Comparing the yields of organic and conventional agriculture. Nature, 485(7397), 229-232. doi:10.1038/nature11069Chandel, N. S., & Tuveson, D. A. (2014). The Promise and Perils of Antioxidants for Cancer Patients. New England Journal of Medicine, 371(2), 177-178. doi:10.1056/nejmcibr1405701Norwegian Scientific Committee for Food Safety Comparison of organic and conventional food and food production (2014) http://www.english.vkm.no/eway/default.aspx?pid = 278&trg = Content_6575&Main_6359 = 6575:0:31,2558&Content_6575 = 6393:1949052::0:6464:1:::0:0.United States Department of Agriculture (2010) Oxygen Radical Absorbance Capacity (ORAC) of selected foods, release 2. http://www.ars.usda.gov/services/docs.htm?docid = 15866.Ingenbleek, Y., & McCully, K. S. (2012). Vegetarianism produces subclinical malnutrition, hyperhomocysteinemia and atherogenesis. Nutrition, 28(2), 148-153. doi:10.1016/j.nut.2011.04.009Organización de Consumidores y Usuarios (2012) Alimentos Ecológicos, naturalmente nos dan la razón (Organic food, we were naturally right). http://www.ocu.org/alimentacion/alimentos/noticias/alimentos-ecologicos-naturalmente-nos-dan-la-razon.Guéguen, L., & Pascal, G. (2010). Le point sur la valeur nutritionnelle et sanitaire des aliments issus de l’agriculture biologique. Cahiers de Nutrition et de Diététique, 45(3), 130-143. doi:10.1016/j.cnd.2010.02.002Bast, A., & Haenen, G. R. M. M. (2013). Ten misconceptions about antioxidants. Trends in Pharmacological Sciences, 34(8), 430-436. doi:10.1016/j.tips.2013.05.010Benbrook C , Zhao X & Davies N , et al. (2008) New evidence confirms the nutritional superiority of plant-based organic foods. http://organiccenter.org/reportfiles/NutrientContentReport.pdf (accessed June 2014).Curl, C. L., Fenske, R. A., & Elgethun, K. (2003). Organophosphorus pesticide exposure of urban and suburban preschool children with organic and conventional diets. Environmental Health Perspectives, 111(3), 377-382. doi:10.1289/ehp.5754Smith-Spangler, C., Brandeau, M. L., Hunter, G. E., Bavinger, J. C., Pearson, M., Eschbach, P. J., … Bravata, D. M. (2012). Are Organic Foods Safer or Healthier Than Conventional Alternatives? Annals of Internal Medicine, 157(5), 348. doi:10.7326/0003-4819-157-5-201209040-00007Del Rio, D., Rodriguez-Mateos, A., Spencer, J. P. E., Tognolini, M., Borges, G., & Crozier, A. (2013). Dietary (Poly)phenolics in Human Health: Structures, Bioavailability, and Evidence of Protective Effects Against Chronic Diseases. Antioxidants & Redox Signaling, 18(14), 1818-1892. doi:10.1089/ars.2012.458

Pseudociencias y medicina

© SEBBM. Se autoriza la reproducción del contenido, siempre que se cite la procedencia.[ES] Los científicos tenemos la obligación moral de divulgar lo que hacemos y que la gente nos entienda. Hay mucho en juego, entre otras cosas, evitar que proliferen estafas como las que se comentan en este artículo.Mulet Salort, JM. (2015). Pseudociencias y medicina. Revista de la Sociedad Española de Bioquímica y Biología Molecular. (178):7-10. http://hdl.handle.net/10251/65505S71017

Letter to the Editor regarding the article by Paganelli et Al

Mulet Salort, JM. (2011). Letter to the Editor regarding the article by Paganelli et Al. Chemical Research in Toxicology. 24(5):609-609. doi:10.1021/tx200077hS60960924

Early establishment response of different Pinus nigra ssp. salzmanii seed sources on contrasting environments: Implications for future reforestation programs and assisted population migration

[EN] Forest restoration constitutes an important issue within adaptive environmental management for climate change at global scale. However, effective implementation of these programs can only be achieved by revising current seed transfer guidelines, as they lack inherent spatial and temporal dynamics associated with climate change. In this sense, provenance trials may provide key information on the relative performance of different populations and/or genotypes under changing ecological conditions. This study addresses a methodological approach to evaluate early plantation performance and the consequent phenotypic plasticity and the pattern of the adaptation of different seed sources in contrasting environments. To this end, six seed sources of Salzmann pine were tested at three contrasting trial sites testing a hypothetical assisted population migration. Adaptation at each site was assessed through Joint Regression and Additive Main effect and Multiplication Interaction (AMMI) models. Most of the observed variation was attributed to the environment (above 90% for all traits), even so genotype and genotype by environment interaction (GxE) were significant. Seedlings out-planted under better site conditions did not differ in survival but in height growth. However, on sites with higher constraints, survival differed among seed sources and diameter growth was high. The adaptation analyses (AMMI) indicated that the cold-continental seed source Soria performed as a generalist seed source, whereas Cordilleras Beticas , the southernmost seed source, was more adapted to harsh environments (frost and drought) in terms of survival. The results supported partially the hypothesis that assisted migration of seed sources makes sense within limited transfer distances, and this was reinforced by the GxE results. The present study could be valuable to address adaptive transfer of seedings in ecological restoration and to determine the suitable seed sources for reforestation programs and assisted population migration under climatic changes. The reported results are based on 3 years' data and need to be considered in this context.This study is a part of the research project: "Application of molecular biology techniques in forest restoration in Mediterranean environments, PAID-05-11" funded by the Universitat Politecnica de Valencia (UPV), program for supporting R&D of new multidisciplinary research lines. The authors are grateful to MeteoCat and Emilio Olid (Meteoclimatic) for the meteorological data and to Jaime Flors and Tragsa for field work and to Dr. Paulo Canas Rodrigues from the Research Center for Mathematics and Applications, Nova University of Lisbon, Portugal, for the deliverance and the guidance of some R codes. The authors also thank the anonymous referees for reviewing the manuscript.Taïbi, K.; Campo García, ADD.; Aguado, A.; Mulet Salort, JM. (2016). Early establishment response of different Pinus nigra ssp. salzmanii seed sources on contrasting environments: Implications for future reforestation programs and assisted population migration. Journal of Environmental Management. 171:184-194. https://doi.org/10.1016/j.jenvman.2016.02.014S18419417

The effect of genotype by environment interaction, phenotypic plasticity and adaptation on Pinus halepensis reforestation establishment under expected climate drifts

[EN] Genotype by environment interaction (GEI) is becoming an important issue within the proactive adaptive silviculture oriented to global changes. However, there is a considerable lack of information on how GEI and phenotypic plasticity may affect early establishment (survival and early growth) performance in many non-commercial forest species, such as Aleppo pine, a key species in semiarid forest restoration programs. The objectives of this study were to (1) evaluate the phenotypic plasticity and adaptation in the broad context of GEI of eleven Aleppo pine seed sources regarding survival, height and diameter growth after outplanting in contrasting core and marginal habitats representing core-to-dry and cold-to-core drifts and to (2) compare the efficiency of joint regression and Additive Main effect and Multiplication Interaction (AMMI) models in elucidating the pattern of the adaptation of the eleven seed sources regarding these traits. Even though phenotypic plasticity was low, more plasticity was observed in the core drift than the dry drift. Specific adaptation to extreme environments was coupled with lower phenotypic plasticity. Among traits, plasticity was lower for survival and height than for diameter in the dry drift and the opposite for the core drift. There were also significant environment, genotype and GEI effects. AMMI models revealed higher capabilities than joint regression in determining seed sources adaptation across environments. Specifically, seed sources with higher plasticity performed better on the core habitat conditions. Southern seed sources of Bética Septentrional and La Mancha suited more to the dry environment. However, Maestrazgo Los Serranos seed source grew better under the cooler local conditions. Levante Interior seed source performed as a generalist genotype adapted to both drifts. These results make a significant contribution towards reforestation programs with practical implications for abiotic stress tolerance and assisted population migration in response to climate change.This work was supported by two research projects: "Application of molecular biology techniques in forest restoration in Mediterranean environments, PAID-05-11" funded by the Universitat Politecnica de Valencia (UPV), program for supporting RandD of new multidisciplinary research lines; and the contract subscribed between the UPV and the Ministry of Environment, Rural and Marine affairs (Centro Nacional de Recursos Geneticos Forestales de Alaquas) through its public partnership TRAGSA titled: "Study of seedling quality and field performance of 12 seed sources of Pinus halepensis Mill.".Taibi, K.; Campo García, ADD.; Aguado, A.; Mulet Salort, JM. (2015). The effect of genotype by environment interaction, phenotypic plasticity and adaptation on Pinus halepensis reforestation establishment under expected climate drifts. Ecological Engineering. 84:218-228. https://doi.org/10.1016/j.ecoleng.2015.09.005S2182288

Testing Aleppo pine seed sources response to climate change by using trial sites reflecting future conditions

Large-scale biogeographical shifts in forest tree distributions are predicted in response to the altered precipitation and temperature regimes associated with climate change. Adaptive forest management to climate change experienced in either stable or rapidly changing environments must consider this fact when carrying out reforestation programs or specifically assisted population migration for conservation purposes. The aim of this study was to compare field performance of eleven seed sources of Aleppo pine outplanted in core and marginal habitats and to assess their phenotypic plasticity for further screening under specific conditions in particular reforestation areas. We hypothesize that current marginal habitat due to low temperature is shifting toward conditions found on the core habitat and that current core habitat will shift toward warmer and drier marginal habitat. Our study reproduced real conditions of reforestation in potential future climatic conditions. Results suggest that it is difficult to predict Aleppo pine provenances' performance in different natural sites from their performance at a single location, even though 'Levante interior' and 'La Mancha' seed sources showed the best overall response among sites. On a site basis, provenances were matched in groups according to their survival and growth responses. Seedlings grown from local seed sources or seed orchards performed better on the core habitat. However, as conditions shifted to marginal habitats, seedlings from climatically similar regions performed better than local sources at least in the short term; our findings suggest that new plantations in areas already affected by global change could be better adapted if they use alternative seed sources.This study is a part of two research projects: "Application of molecular biology techniques in forest restoration in Mediterranean environments, PAID-05-11" funded by the Universitat Politecnica de Valencia (UPV), program for supporting R&D of new multidisciplinary research lines; and the contract subscribed between the UPV and the Ministry of Environment, Rural and Marine affairs (Centro Nacional de Recursos Geneticos Forestales de Alaquas) through its public partnership TRAGSA titled: "Study of seedling quality and field performance of 12 seed sources of Pinus halepensis Mill." The authors are grateful to Amparo Pedros-Mari for field work in La Hunde, to the Valencia Regional Government (CMAAUV, Generalitat Valenciana) and VAERSA staff for their support in allowing the use of the experimental forest of La Hunde. We thank Dr. Kasten Dumroese from USDA Forest Service, Rocky Mountain Research Station for his critical and valuable comments on the draft manuscript. Also, we thank the anonymous referees for their comments, which significantly improved the final manuscript.Taïbi, K.; Campo García, ADD.; Mulet Salort, JM.; Flors, J.; Aguado, A. (2014). Testing Aleppo pine seed sources response to climate change by using trial sites reflecting future conditions. New Forests. 45(5):603-624. https://doi.org/10.1007/s11056-014-9423-yS603624455Agúndez ID, Degen B, von Wuehlisch G, Alia R (1997) Genetic variation of Aleppo pine (Pinus halepensis mill.). For Gen 4(4):201–209Aitken SN, Yeaman S, Holliday JA, Wang T, Curtis-McLane S (2008) Adaptation, migration or extirpation: climate change outcomes for tree populations. Evol App 1:95–111. doi: 10.1111/j.1752-4571.2007.00013.xAlía R, Garcia del Barrio JM, Iglesias S, Mancha JA, de Miguel J, Nicolas JL, Perez F, Sanchez de Ron D (2009) Regiones de procedencia de especies forestales en España. Organismo Autonomo Parques Nacionales, MadridAtzmon N, Moshe Y, Schiller G (2004) Ecophysiological response to severe drought in Pinus halepensis Mill. trees of two provenances. Plant Ecol 171:15–22Bariteau M (1992) Variabilité géographique et adaptation aux contraintes du milieu méditerranéen des pins de la section halepensis : résultats (provisoires) d’un essai en plantations comparatives en France. Ann Sci For 49:261–276Benito-Garzón M, Alía R, Robson TM, Zavala MA (2011) Intra-specific variability and plasticity influence potential tree species distributions under climate change. Glob Ecol Biogeogr 20:766–778Climent J, Prada MA, Calama R, Chambel MR, Sánchez de Ron D, Alía R (2008) To grow or to seed: ecotypic variation in reproductive allocation and cone production by young female Aleppo pine (Pinus halepensis, Pinaceae). Am J Bot 95(7):833–842Cortina J, Vilagrosa A, Trubat R (2013) The role of nutrients for improving seedling quality in drylands. New For. doi: 10.1007/s11056-013-9379-3Cregg BM, Zhang JW (2001) Physiology and morphology of Pinus sylvestris seedlings from diverse sources under cyclic drought stress. For Ecol Manage 154:131–139del Campo AD, Navarro-Cerrillo RM, Hermoso J, Ibáñez AJ (2007a) Relationships between root growth potential and field performance in Aleppo pine. Ann For Sci 64:541–548del Campo AD, Navarro-Cerrillo RM, Hermoso J, Ibáñez AJ (2007b) Relationships between site and stock quality in Pinus halepensis Mill. reforestation on semiarid landscapes in eastern Spain. Ann For Sci 64:719–731del Campo AD, Hermoso J, Flors J, Lidón A, Navarro-Cerrillo RM (2011) Nursery location and potassium enrichment in Aleppo pine stock 2. Performance under real and hydrogel-mediated drought conditions. Forestry 84(3):235–245Esteban GL, Martín JA, de Palacios P, Fernández FG, López R (2010) Adaptive anatomy of Pinus halepensis trees from different Mediterranean environments in Spain. Trees 24:19–30. doi: 10.1007/s00468-009-0375-3European Forest Institute (2009) A Mediterranean Forest Research Agenda-MFRA. 2010-2020. Mediterranean Regional Office–EFIMED. www.efimed.efi.int/files/attachments/efimed/mediterranean_forest_research_agenda_2010-2020.pdfFAO (2013) State of Mediterranean Forests 2013. www.fao.org/docrep/017/i3226e/i3226e.pdfFerrio JP, Voltas J (2005) Carbon and oxygen isotope ratios in wood constituents of Pinus halepensis as indicators of precipitation, temperature and vapour pressure deficit. Tellus B 57:164–173Gandullo J, Sánchez-Palomares O (1994) Site ecology of Spanish pines, ICONA, Ministry of Agriculture, fisheries and food, Madrid (in Spanish)Garrido A, Willaarts B, López-Gunn E, Rey D (2012) Considerations on climate variability and change in Spain. In: De Stefano L, Ramón Llamas M (eds) Water, agriculture and the environment in Spain can we square the circle? CRC Press, Boca Raton, pp 191–202Giorgi F, Lionello P (2008) Climate change projections for the Mediterranean region. Glob Planet Change 63:90–104Grivet D, Sebastiani F, González-Martínez SC, Vendramin GG (2009) Patterns of polymorphism resulting from long-range colonization in the Mediterranean conifer Aleppo pine. New Phytol 184:1016–1028Hernandez EI, Vilagrosa A, Pausas JG, Bellot J (2010) Morphological traits and water use strategies in seedlings of Mediterranean coexisting species. Plant Ecol 207:233–244IPCC (2001) The Scientific Basis. In: Houghton JT, Ding Y, Griggs DJ, Noguer M, Van Der Linden PJ, Dai X, Maskell K, Johnsson CA (eds) Climate Change 2001. Cambridge University Press, Cambridge, p 881Kaplan EL, Meier P (1958) Nonparametric estimation from incomplete observations. J Am Stat Assoc 53:457–481Landis TD, Dumroese RK, Haase DL (2010) The container tree nursery manual: Seedling processing, storage, and outplanting. vol. 7. USDA For. Serv., Agr. Handbook. 674, Washington, p 192Matesanz S, Valladares F (2013) Ecological and evolutionary responses of Mediterranean plants to global change. doi: 10.1016/j.envexpbot.2013.09.004Mayr S (2007) Limits in water relations. Trees at their upper limit. In: Wieser G, Tausz M (eds) Tree life limitation at the Alpine timberline. Springer, Berlin, pp 145–162McDowell N, Pockman WT, Allen CD, Breshears DD, Cobb N, Kolb T, Plaut J, Sperry J, West A, Williams DG, Yepez EA (2008) Mechanisms of plant survival and mortality during drought: why do some plants survive while others succumb to drought? New Phytol 178:719–739Metzger MJ, Bunce RGH, Leemans R, Viner D (2008) Projected environmental shifts under climate change: European trends and regional impacts. Environ Conserv 35(1):64–75Mulet JM, Martin DE, Loewith R, Hall MN (2006) Mutual antagonism of target of rapamycin and calcineurin signaling. J Biol Chem 281(44):33000–33007Oliet JA, Puértolas J, Planelles R, Jacobs DF (2013) Nutrient loading of forest tree seedlings to promote stress resistance and field performance: a Mediterranean perspective. New For 44:649–669. doi: 10.1007/s11056-013-9382-8Oliver J, Bogino S, Spiecker H, Bravo F (2012) Climate impact on growth dynamic and intra-annual density fluctuations in Aleppo pine (Pinus halepensis) trees of different crown classes. Dendro 30:35–47Persson B (1994) Effect of provenance transfer on survival in nine experimental series with Pinus sylvestris (L.) in northern Sweden. Scand J Forest Res 9:275–287Potter KM, Hargrove WW (2012) Determining suitable locations for seed transfer under climate change: a global quantitative method. New For 43(5–6):581–599Puértolas J, Gil L, Pardos JA (2005) Effects of nitrogen fertilization and temperature on frost hardiness of Aleppo pine (Pinus halepensis Mill.) seedlings assessed by chlorophyll fluorescence. Forestry 78(5):501–511Quézel P, Médail F (2003) Ecologie et biogéographie des forêts du basin méditerranéen. Elsevier (Collection Environnement), Paris, 573 pRæbild A, Graudal L, Khan SR (2003) Evaluation of a Prosopis cineraria provenance trial at Dagar Kotli, Pakistan. Trial no. 23 in the arid zone series Results and Documentation No. 28. Danida Forest Seed Centre, Humlebaek, DenmarkRehfeldt GE, Tchebakova NM, Parfenova YI, Wykoff WR, Kuzmina NA, Milyutin II (2002) Intraspecific responses to climate change in Pinus sylvestris. Glob Change Biol 8:912–929Reich PB, Oleksyn J (2008) Climate warming will reduce growth and survival of Scots pine except in the far north. Ecol Lett 11:588–597. doi: 10.1111/j.1461-0248.2008.01172.xSáenz-Romero C, Beaulieu J, Rehfeldt GE (2011) Altitudinal genetic variation among P. patula in growth chambers simulating global warming temperatures. Agrocien 45:399–411Schiller G, Atzmon N (2009) Performance of Aleppo pine (Pinus halepensis) provenances grown at the edge of the Negev desert: a review. J Arid Environ 73:1051–1057Schmidtling RC (1994) Use of provenance tests to predict response to climatic change: loblolly pine and Norway spruce. Tree Physiol 14:805–817Soto A, Robledo-Arnuncio JJ, González-Martínez J, Smouse BE, Alía R (2010) Climatic niche and neutral genetic diversity of the six Iberian pine species: a retrospective and prospective view. Mol Ecol 19(7):1396–1409Sultan SE, Spencer HG (2002) Metapopulation structure favors plasticity over local adaptation. Am Nat 160:271–283Tognetti R, Michelozzi M, Giovannelli A (1997) Geographical variation in water relations, hydraulic architecture and terpene composition of Aleppo pine seedlings from Italian provenances. Tree Physiol 17:241–250United Nations, United Nations Economic Commission for Europe & Food and Agriculture Organization of the United Nations (2011) The European Forest Sector Outlook Study II 2010-2030. 107 pp. http://www.fao.org/docrep/016/ap406e/ap406e00.pdfVallejo VR, Smanis A, Chirino E, Fuentes D, Valdecantos A, Vilagrosa A (2012) Perspectives in dryland restoration: approaches for climate change adaptation. New For 43:561–579van Kleunen M, Fischer M (2007) Progress in the detection of costs of phenotypic plasticity in plants. New Phytol 176:727–730Vennetier M, Vilà B, Liang E, Guibal F, Taahbet A, Gadbin-Henry C (2007) Impact of climate change on pines forest productivity and on the shift of a bioclimatic limit in Mediterranean area. In: Leon e V, Lovreglio R (ed) Proceedings of the international workshop MEDPINE 3: conservation, regeneration and restoration of Mediterranean pines and their ecosystems. Bari : CIHEAM, 2007. pp 189–197 (Options Méditerranéennes : Série A. Séminaires Méditerranéen s; n. 75)Villar-Salvador P, Puértolas J, Cuesta B, Peñuelas JL, Uscola M, Heredia-Guerrero N, Rey Benayas JM (2012) Increase in size and nitrogen concentration enhances seedling survival in Mediterranean plantations. Insights from an ecophysiological conceptual model of plant survival. New For. doi 10.1007/s11056-012-9328-6Voltas J, Chambel MR, Prada MA, Ferrio JP (2008) Climate-related variability in carbon and oxygen stable isotopes among populations of Aleppo pine grown in common-garden tests. Trees 22:759–769Williams MI, Dumroese RK (2013) Preparing for climate change: forestry and assisted migration. J For 111(4):287–297Zobel B, Talbert JJ (1984) Applied forest tree improvement. Wiley, New York, pp 75–11

Plant hemoglobins can be maintained in functional form by reduced flavins in the nuclei and confer differential tolerance to nitro-oxidative stress

39 Pags., 1 Tabl., 5 Figs., with Supplementary Supporting Information (1 Suppl. Tabl., 5 Suppl. Figs.). The definitive version is available at: http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-313XThe heme of bacteria, plant and animal hemoglobins (Hbs) must be in the ferrous state to bind O2 and other physiological ligands. Here we have characterized the full set of non-symbiotic (class 1 and 2) and ‘truncated’ (class 3) Hbs of Lotus japonicus. Class 1 Hbs are hexacoordinate, but class 2 and 3 Hbs are pentacoordinate. Three of the globins, Glb1-1, Glb2 and Glb3-1, are nodule-enhanced proteins. The O2 affinity of Glb1-1 (50 pm) was the highest known for any Hb, and the protein may function as an O2 scavenger. The five globins were reduced by free flavins, which transfer electrons from NAD(P)H to the heme iron under aerobic and anaerobic conditions. Class 1 Hbs were reduced at very fast rates by FAD, class 2 Hbs at slower rates by both FMN and FAD, and class 3 Hbs at intermediate rates by FMN. The members of the three globin classes were immunolocalized predominantly in the nuclei. Flavins were quantified in legume nodules and nuclei, and their concentrations were sufficient to maintain Hbs in their functional state. All Hbs, except Glb1-1, were expressed in a flavohemoglobin-deficient yeast mutant and found to confer tolerance to oxidative stress induced by methyl viologen, copper or low temperature, indicating an anti-oxidative role for the hemes. However, only Glb1-2 and Glb2 afforded protection against nitrosative stress induced by S-nitrosoglutathione. Because this compound is specifically involved in transnitrosylation reactions with thiol groups, our results suggest a contribution of the single cysteine residues of both proteins in the stress response.This work was funded by MINECO-FEDER (grant AGL2011-24524) and Gobierno de Aragón-FSE (group A53). M.S. was supported by a predoctoral contract from Junta de Ampliación de Estudios-CSIC.Peer reviewe

Peptidyl-prolyl cis-trans isomerase ROF2 modulates intracellular pH homeostasis in Arabidopsis

[EN] Intracellular pH must be kept close to neutrality to be compatible with cellular functions, but the mechanisms of pH homeostasis and the responses to intracellular acidification are mostly unknown. In the plant Arabidopsis thaliana, we found that intracellular acid stress generated by weak organic acids at normal external pH induces expression of several chaperone genes, including ROF2, which encodes a peptidyl-prolyl cis-trans isomerase of the FK506-binding protein class. Loss of function of ROF2, and especially double mutation of ROF2 and the closely related gene ROF1, results in acid sensitivity. Over-expression of ROF2 confers tolerance to intracellular acidification by increasing proton extrusion from cells. The activation of the plasma membrane proton pump (H+-ATPase) is indirect: over-expression of ROF2 activates K+ uptake, causing depolarization of the plasma membrane, which activates the electrogenic H+ pump. The depolarization of ROF2 over-expressing plants explains their tolerance to toxic cations such as lithium, norspermidine and hygromycin B, whose uptake is driven by the membrane potential. As ROF2 induction and intracellular acidification are common consequences of many stresses, this mechanism of pH homeostasis may be of general importance for stress tolerance.This work was supported by grants BFU2008-00604 from the Ministerio de Ciencia e Innovacion (Madrid, Spain) and PROMETEO/2010/ 038 of the 'Conselleria de Educacion' (Valencia, Spain). We thank Dr Eugenio Grau (Sequencing Service, Instituto de Biologia Molecular y Celular de Plantas, Valencia, Spain) for sequencing of the various genes, and Dr Vicente Fornes (Instituto de Tecnologia Quimica, Valencia, Spain) for assistance with atomic absorption spectrophotometry. None of the authors has a conflict of interest to declare.Bissoli, G.; Niñoles Rodenes, R.; Fresquet Corrales, S.; Palombieri, S.; Bueso Ródenas, E.; Rubio, L.; Garcia-Sanchez, MJ.... (2012). Peptidyl-prolyl cis-trans isomerase ROF2 modulates intracellular pH homeostasis in Arabidopsis. Plant Journal. 70(4):704-716. https://doi.org/10.1111/j.1365-313X.2012.04921.xS70471670

C2-Domain Abscisic Acid-Related Proteins Mediate the Interaction of PYR/PYL/RCAR Abscisic Acid Receptors with the Plasma Membrane and Regulate Abscisic Acid Sensitivity in Arabidopsis

Supplemental Data: http://www.plantcell.org/content/26/12/4802/suppl/DC1© 2014 American Society of Plant BiologistsMembrane-delimited abscisic acid (ABA) signal transduction plays a critical role in early ABA signaling, but the molecular mechanisms linking core signaling components to the plasma membrane are unclear. We show that transient calcium-dependent interactions of PYR/PYL ABA receptors with membranes are mediated through a 10-member family of C2-domain ABA-related (CAR) proteins in Arabidopsis thaliana. Specifically, we found that PYL4 interacted in an ABA-independent manner with CAR1 in both the plasma membrane and nucleus of plant cells. CAR1 belongs to a plant-specific gene family encoding CAR1 to CAR10 proteins, and bimolecular fluorescence complementation and coimmunoprecipitation assays showed that PYL4-CAR1 as well as other PYR/PYL-CAR pairs interacted in plant cells. The crystal structure of CAR4 was solved, which revealed that, in addition to a classical calcium-dependent lipid binding C2 domain, a specific CAR signature is likely responsible for the interaction with PYR/PYL receptors and their recruitment to phospholipid vesicles. This interaction is relevant for PYR/PYL function and ABA signaling, since different car triple mutants affected in CAR1, CAR4, CAR5, and CAR9 genes showed reduced sensitivity to ABA in seedling establishment and root growth assays. In summary, we identified PYR/PYL-interacting partners that mediate a transient Ca2+-dependent interaction with phospholipid vesicles, which affects PYR/PYL subcellular localization and positively regulates ABA signaling.We thank Joerg Kudla (University of Munster) for kindly providing plasma membrane markers. This work was supported by the Ministerio de Ciencia e Innovacion, Fondo Europeo de Desarrollo Regional, and Consejo Superior de Investigaciones Cientificas (Grants BIO2011-23446 to P.L.R and BFU2011-25384 to A. A.; fellowships to L.R., R.A., and A.C.I.-G.; BES-2009- 016569; JAE-DOC contract to M.G.-G.) as well as the Senacyt-Ifarhu (Panama) (fellowship to M.D.).Rodriguez, L.; Gonzalez Guzman, M.; Díaz, M.; Rodrigues, A.; Izquierdo Garcia, AC.; Peirats-Llobet, M.; Fernández López, MA.... (2014). C2-Domain Abscisic Acid-Related Proteins Mediate the Interaction of PYR/PYL/RCAR Abscisic Acid Receptors with the Plasma Membrane and Regulate Abscisic Acid Sensitivity in Arabidopsis. Plant Cell. 26(12):4802-4820. doi:10.1105/tpc.114.129973S48024820261