Water-deficit tolerance in citrus is mediated by the down regulation of PIP gene expresión in roots

Water deficit (WD) is a growing problem in agriculture. In citrus crops, genetically-determined characteristics of the rootstock are important factors in plant responses to WD. Aquaporins are involved in regulating the water supply to the plant by mediating water flow through the cell membranes. Recent studies support a direct role for aquaporins in plant water relations and demonstrate their involvement in tolerance to WD. This study investigates the relationship between photosynthetic and water-balance parameters with levels of expression of aquaporins in conditions of moderate WD in the rootstocks Poncirus trifoliata (L.) Raf. (PT), Cleopatra Mandarin (Citrus reshni Hort. ex Tan.) (CM) and 030115 (a hybrid of the two former rootstocks). Under conditions of WD, the hybrid 030115 drastically reduced aquaporin expression, accompanied by a loss of plant vigour but without reducing the net CO2 assimilation (ACO2). PT maintained the same level of aquaporin expression under WD as under normal irrigation conditions, but suffered a sharp reduction in ACO2. CM, which has lower expression of aquaporins than PT under both normal irrigation conditions and WD, responded better to water stress conditions than PT. Thus, low levels of aquaporins, or repression of their expression, accompanied by decreased plant vigour resulted in a decrease in plasma membrane permeability, thereby facilitating water retention in the cells under conditions of water stress. This can induce water stress tolerance in citrus rootstocks.Rodríguez Gamir, J. (2010). Water-deficit tolerance in citrus is mediated by the down regulation of PIP gene expresión in roots. http://hdl.handle.net/10251/14155Archivo delegad

CONDUCTANCIA HIDRÁULICA EN PATRONES DE CÍTRICOS

La conductancia hidráulica determina la capacidad de transporte de agua afectando a las relaciones hídrias de la planta así como a la eficiencia de absorción de agua y nutrientes. Los patrones de cítricos difieren en su conductancia hidráulica debido a diferencias en la anatomía de los elementos vasculares o en la distribución del sistema radical pudiendo ser el principal factor que regula el desarrollo de los frutos y la respuesta de la planta a situaciones de estrés. Las relaciones hídricas pueden verse alteradas por estreses abióticos como el déficit hídrico, la salinidad o la asfixia radical. Recientes estudios realizados en especies no cítricas demuestran que las acuaporinas intervienen de manera importante en las relaciones hídricas de la planta y que los estímulos ambientales pueden regular su expresión. Ésta, a su vez, puede estar regulada por el pH citosólico. Por tanto, el principal objetivo de la presente tesis fue estudiar la conductancia hidráulica de los patrones de cítricos, determinando su influencia en la transpiración, los factores que la regulan y su papel en la respuesta de la planta a las situaciones de estrés abiótico. En los ensayos realizados, se utilizaron distintos patrones injertados y sin injertar. Se observaron diferencias en la capacidad de absorción de agua de los diferentes patrones, la cual tuvo una marcada influencia en el proceso de transpiración de la planta. La conductancia hidráulica se relacionó tanto con la expresión de acuaporinas como con la anatomía del xilema. Por otra parte, en condiciones de estrés hídrico se demostró que las características hidráulicas del patrón pueden determinar el grado de tolerancia de la planta a este estrés. Al someter las plantas a estrés salino se observó que la diferencia en la expresión de acuaporinas entre genotipops de cítricos afecta a la exclusión de cloruro de las hojas, determinando así su tolerancia a la salinidad. Por último, en condiciones de asfixia radical se demostró que lRodríguez Gamir, J. (2012). CONDUCTANCIA HIDRÁULICA EN PATRONES DE CÍTRICOS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/17838Palanci

Estudio de las deformaciones resilientes de los materiales granulares sueltos utilizados en capas de base de carreteras

Este congreso tivo lugar en París do 11 ao 15 de xuño de 2001

Propiedades mecánicas de las capas de base y subbase construidas con materiales granulares en los firmes de carreteras

Este VI Simposio tivo lugar en decembro de 2000 na Habana (Cuba).[Resumen:] En los firmes de carreteras los materiales granulares sueltos desempeñan un importante papel estructural. Esto es así porque, por un lado, durante la etapa de construcción del firme éstos soportan el tráfico de obra y proporcionan un cimiento sobre el cual las capas superiores puedan situarse y compactarse. Por otro lado, en un firme terminado actúan como amortiguadores de las cargas del tráfico. En esta comunicación se va a realizar una breve descripción de los modelos de predicción del comportamiento resiliente de los materiales granulares bajo las cargas del tráfico como de los diferentes modelos de comportamiento de la deformación permanente

Recensiones [Revista de Historia Económica Año XI Otoño 1993 n. 3 pp. 567-693]

Editada en la Universidad Carlos IIIMiguel Ángel Melón Jiménez. Los orígenes del capital comercial y financiero en Extremadura. Compañías de comercio, comerciantes y banqueros de Cáceres (1773- 1836) (Por Joan Carles Maixé i Altes).-- Carmen Yuste. Comerciantes mexicanos en el siglo XVIII (Por Juan Carlos Sola Corbacho).-- Arantxa Otaegui Arizmendi. Guerra y crisis de la hacienda local Las ventas de bienes comunales y de propios en Guipúzcoa, 1764-1814 (Por Carlos Larrinaga Rodríguez).-- Pedro Pérez HerreroRegión e Historia en México (1700-1850). Métodos de análisis regional (Por Juan Carlos Sola Corbacho).-- Juan Antonio López Cordero. Sociedad y economía del Jaén isabelino (Por Luis Garrido González).-- Francisco Cobo Romero. Labradores, campesinos y jornaleros. Protesta social y diferenciación interna del campesinado jiennense en los orígenes de la guerra civil(1931-1936) (Por Luis Garrido González).-- Van Der Wee (dir), R. Bogaert y G. Kurgan-Van Hentenryk.La banque en Occident (Por Gabriel Tortell).-- Raaj Sah y Joseph E. Stiglitz.Peasanls versus City-dwellers. Taxation and the Burden of Economic Development. (Por Jordi Palafox Gamir).-- Wayne Parsons.The Power ofthe Financial Press, journalism and Economic Opinión in Britain and America (Por Carlos Rodríguez Braun)Publicad

Crop load does not increase the photosynthetic rate in Citrus leaves under regular cropping conditions. A study throughout the year

[EN] The objective of this work was to study the influence of fruit load on CO2 assimilation in the leaves of citrus trees presenting alternate bearing habits, and the importance of this factor on photosynthetic rate variability throughout the year and under regular cropping conditions. The photosynthetic rate was measured on 60 days throughout the year on field-grown sweet orange plants under natural conditions in the Valencian Community, the most important citrus-producing area of Spain. The experiments were performed on the 'on' (high crop) and 'off' (low crop) bearing 40-year-old Salustiana sweet orange trees growing in the same orchard. Gas exchange and fluorescence parameters were measured during the year in young and old leaves on sun-exposed branches with and without fruit in the 'on' trees, and in fruitless branches of the 'off' trees. In non-manipulated Citrus trees, fruit load has no significant effect in any season on the photosynthetic rate in the leaves from branches without fruit. However, in high crop trees, the leaves of branches bearing fruit present a slightly lower photosynthetic rates (approx. 10%) than those of fruitless branches. Variations in mineral content (N, K and P) might explain not only these differences, but also the lower photosynthesis rate observed in old leaves (13-24 month-old leaves). Environmental conditions were the main factor for the variation of the photosynthetic rate, with variability of the monthly mean photosynthetic rate being much lower than that between days in the same month.González Nebauer, S.; Arenas, C.; Rodríguez Gamir, J.; Bordon, Y.; Fortunato Almeida, A.; Monerri Huguet, MC.; Guardiola Barcena, JL.... (2013). Crop load does not increase the photosynthetic rate in Citrus leaves under regular cropping conditions. A study throughout the year. Scientia Horticulturae. 160:358-365. doi:10.1016/j.scienta.2013.06.008S35836516

Phenotypic plasticity and water flux rates of Citrus root orders under salinity

Knowledge about the root system structure and the uptake efficiency of root orders is critical to understand the adaptive plasticity of plants towards salt stress. Thus, this study describes the phenological and physiological plasticity of Citrus volkameriana rootstocks under severe NaCl stress on the level of root orders. Phenotypic root traits known to influence uptake processes, for example frequency of root orders, specific root area, cortical thickness, and xylem traits, did not change homogeneously throughout the root system, but changes after 6 months under 90 mM NaCl stress were root order specific. Chloride accumulation significantly increased with decreasing root order, and the Cl− concentration in lower root orders exceeded those in leaves. Water flux densities of first-order roots decreased to <20% under salinity and did not recover after stress release. The water flux densities of higher root orders changed marginally under salinity and increased 2- to 6-fold in second and third root orders after short-term stress release. Changes in root order frequency, morphology, and anatomy indicate rapid and major modification of C. volkameriana root systems under salt stress. Reduced water uptake under salinity was related to changes of water flux densities among root orders and to reduced root surface areas. The importance of root orders for water uptake changed under salinity from root tips towards higher root orders. The root order-specific changes reflect differences in vulnerability (indicated by the salt accumulation) and ontogenetic status, and point to functional differences among root orders under high salinity

Depletion of abscisic acid levels in roots of flooded Carrizo citrange (Poncirus trifoliata L. Raf. x Citrus sinensis L. Osb.) plants is a stress-specific response associated to the differential expression of PYR/PYL/RCAR receptors

[EN] Soil flooding reduces root abscisic acid (ABA) levels in citrus, conversely to what happens under drought. Despite this reduction, microarray analyses suggested the existence of a residual ABA signaling in roots of flooded Carrizo citrange seedlings. The comparison of ABA metabolism and signaling in roots of flooded and water stressed plants of Carrizo citrange revealed that the hormone depletion was linked to the upregulation of CsAOG, involved in ABA glycosyl ester (ABAGE) synthesis, and to a moderate induction of catabolism (CsCYP707A, an ABA 8'-hydroxylase) and buildup of dehydrophaseic acid (DPA). Drought strongly induced both ABA biosynthesis and catabolism (CsNCED1, 9-cis-neoxanthin epoxycarotenoid dioxygenase 1, and CsCYP707A) rendering a significant hormone accumulation. In roots of flooded plants, restoration of control ABA levels after stress release was associated to the upregulation of CsBGLU18 (an ABA beta-glycosidase) that cleaves ABAGE. Transcriptional profile of ABA receptor genes revealed a different induction in response to soil flooding (CsPYL5) or drought (CsPYL8). These two receptor genes along with CsPYL1 were cloned and expressed in a heterologous system. Recombinant CsPYL5 inhibited Delta NHAB1 activity in vitro at lower ABA concentrations than CsPYL8 or CsPYL1, suggesting its better performance under soil flooding conditions. Both stress conditions induced ABA-responsive genes CsABI5 and CsDREB2A similarly, suggesting the occurrence of ABA signaling in roots of flooded citrus seedlings. The impact of reduced ABA levels in flooded roots on CsPYL5 expression along with its higher hormone affinity reinforce the role of this ABA receptor under soil-flooding conditions and explain the expression of certain ABA-responsive genes.This work was supported by Ministerio de Economia y Competitividad (MINECO), Fondo Europeo de Desarrollo Regional (FEDER) and Universitat Jaume I through grants No. AGL201676574-R, UJI-B2016-23/UJI-B2016-24 to A.G-C. and V.A. and MINECO, FEDER and Consejo Superior de Investigaciones Cientificas (CSIC) through grant BIO2014-52537-R to P.L.R. S.I.Z. and M.M. were supported by predoctoral grants from Universitat Jaume I and Generalitat Valenciana, respectively. M.G.G. was recipient of a "JAE-DOC" contract from the CSIC. Mass spectrometry analyses were performed at the central facilities (Servei Central d'Instrumentacio Cientifica, SCIC) of Universitat Jaume I.Arbona, V.; Zandalinas, SI.; Manzi, M.; González Guzmán, M.; Rodríguez Egea, PL.; Gómez-Cadenas, A. (2017). Depletion of abscisic acid levels in roots of flooded Carrizo citrange (Poncirus trifoliata L. Raf. x Citrus sinensis L. Osb.) plants is a stress-specific response associated to the differential expression of PYR/PYL/RCAR receptors. Plant Molecular Biology. 93(6):623-640. https://doi.org/10.1007/s11103-017-0587-7S623640936Agarwal PK, Jha B (2010) Transcription factors in plants and ABA dependent and independent abiotic stress signalling. Biol Plant 54:201–212Agustí J, Merelo P, Cercós M, Tadeo FR, Talón M (2008) Ethylene-induced differential gene expression during abscission of citrus leaves. J Exp Bot 59:2717–2733. doi: 10.1093/jxb/ern138Antoni R, Gonzalez-Guzman M, Rodriguez L, Rodrigues A, Pizzio G, Rodriguez PL (2012) Selective inhibition of clade a phosphatases type 2 C by PYR/PYL/RCAR abscisic acid receptors. Plant Physiol 158:970–980. doi: 10.1104/pp.111.188623Antoni R, Gonzalez-Guzman M, Rodriguez L, Peirats-Llobet M, Pizzio G, Fernandez M, De Winne N, De Jaeger G, Dietrich D, Bennett MJ, Rodriguez PL (2013) PYRABACTIN RESISTANCE1-LIKE8 plays an important role for the regulation of abscisic acid signaling in root. Plant Physiol 161:491–931. doi: 10.1104/pp.112.208678Arbona V, Gómez-Cadenas A (2008) Hormonal modulation of citrus responses to flooding. J Plant Growth Regul 27:241–250. doi: 10.1007/s00344-008-9051-xArbona V, López-climent MF, Pérez-Clemente RM, Gómez-cadenas A (2009) Maintenance of a high photosynthetic performance is linked to flooding tolerance in citrus. Environ Exp Bot 66:135–142. doi: 10.1016/j.envexpbot.2008.12.011Argamasilla R, Gómez-Cadenas A, Arbona V (2013) Metabolic and regulatory responses in citrus rootstocks in response to adverse environmental conditions. J Plant Growth Regul 33:169–180. doi: 10.1007/s00344-013-9359-zBaron KN, Schroeder DF, Stasolla C (2012) Transcriptional response of abscisic acid (ABA) metabolism and transport to cold and heat stress applied at the reproductive stage of development in Arabidopsis thaliana. Plant Sci 188–189:48–59. doi: 10.1016/j.plantsci.2012.03.001Benschop JJ, Millenaar FF, Smeets ME, Van Zanten M, Voesenek LACJ, Peeters AJM (2007) Abscisic acid antagonizes ethylene-induced hyponastic growth in Arabidopsis. Plant Physiol 143:1013–1023Chen R, Jiang H, Li L, Zhai Q, Qi L, Zhou W, Liu X, Li H, Zheng W, Sun J, Li C (2012) The Arabidopsis mediator subunit MED25 differentially regulates jasmonate and abscisic acid signaling through interacting with the MYC2 and ABI5 transcription factors. Plant Cell 24:2898–2916. doi: 10.1105/tpc.112.098277De Ollas C, Hernando B, Arbona V, Gómez-Cadenas A (2013) Jasmonic acid transient accumulation is needed for abscisic acid increase in citrus roots under drought stress conditions. Physiol Plant 147:296–306. doi: 10.1111/j.1399-3054.2012.01659.xDupeux F, Santiago J, Betz K, Twycross J, Park S-Y, Rodriguez L, Gonzalez-Guzman M, Jensen MR, Krasnogor N, Blackledge M, Holdsworth M, Cutler SR, Rodriguez PL, Márquez JA (2011) A thermodynamic switch modulates abscisic acid receptor sensitivity. EMBO J 30:4171–4184. doi: 10.1038/emboj.2011.294Finkelstein RR, Rock CD (2002) Abscisic Acid biosynthesis and response. Arabidopsis Book 1:e0058. doi: 10.1199/tab.0058Fuchs S, Tischer SV, Wunschel C, Christmann A, Grill E (2014) Abscisic acid sensor RCAR7/PYL13, specific regulator of protein phosphatase coreceptors. Proc Natl Acad Sci U S A 111:5741–5746. doi: 10.1073/pnas.1322085111Fukao T, Yeung E, Bailey-Serres J (2011) The submergence tolerance regulator SUB1A mediates crosstalk between submergence and drought tolerance in rice. Plant Cell 23:412–427. doi: 10.1105/tpc.110.080325Gonzalez-Guzman M, Rodriguez L, Lorenzo-Orts L, Pons C, Sarrion-Perdigones A, Fernandez M a, Peirats-Llobet M, Forment J, Moreno-Alvero M, Cutler SR, Albert A, Granell A, Rodriguez PL (2014) Tomato PYR/PYL/RCAR abscisic acid receptors show high expression in root, differential sensitivity to the abscisic acid agonist quinabactin, and the capability to enhance plant drought resistance. J Exp Bot 65:1–14. doi: 10.1093/jxb/eru219González-Guzmán M, Apostolova N, Bellés JM, Barrero JM, Piqueras P, Ponce MR, Micol JL, Serrano R, Rodríguez PL (2002) The short-chain alcohol dehydrogenase ABA2 catalyzes the conversion of xanthoxin to abscisic aldehyde. Plant Cell 14:1833–1846. doi: 10.1105/tpc.002477.developmentHsu F-C, Chou M-Y, Peng H-P, Chou S-J, Shih M-C (2011) Insights into hypoxic systemic responses based on analyses of transcriptional regulation in Arabidopsis. PLoS ONE 6:e28888. doi: 10.1371/journal.pone.0028888Krochko JE, Abrams GD, Loewen MK, Abrams SR, Cutler AJ (1998) (+)-Abscisic Acid 8-hydroxylase is a cytochrome P450 monooxygenase. Plant Physiol 860:849–860. doi: 10.1104/pp.118.3.849Lawlor DW (2013) Genetic engineering to improve plant performance under drought: physiological evaluation of achievements, limitations, and possibilities. J Exp Bot 64:83–108. doi: 10.1093/jxb/ers326Lee SC, Luan S (2012) ABA signal transduction at the crossroad of biotic and abiotic stress responses. Plant Cell Environ 35:53–60. doi: 10.1111/j.1365-3040.2011.02426.xLiu Q, Kasuga M, Sakuma Y, Abe H, Miura S, Yamaguchi-Shinozaki K, Shinozaki K (1998) Two transcription factors, DREB1 and DREB2, with an EREBP/AP2 DNA binding domain separate two cellular signal transduction pathways in drought- and low-temperature-responsive gene expression, respectively, in Arabidopsis. Plant Cell 10:1391–1406Mittal A, Gampala SSL, Ritchie GL, Payton P, Burke JJ, Rock CD (2014) Related to ABA-Insensitive3(ABI3)/Viviparous1 and AtABI5 transcription factor coexpression in cotton enhances drought stress adaptation. Plant Biotechnol J 12:578–589. doi: 10.1111/pbi.12162Naika M, Shameer K, Mathew OK, Gowda R, Sowdhamini R (2013) STIFDB2: an updated version of plant stress-responsive transcription factor database with additional stress signals, stress-responsive transcription factor binding sites and stress-responsive genes in Arabidopsis and rice. Plant Cell Physiol 54:e8. doi: 10.1093/pcp/pcs185Nambara E, Marion-Poll A (2005) Abscisic acid biosynthesis and catabolism. Annu Rev Plant Biol 56:165–185. doi: 10.1146/annurev.arplant.56.032604.144046Narusaka Y, Nakashima K, Shinwari ZK, Sakuma Y, Furihata T, Abe H, Narusaka M, Shinozaki K, Yamaguchi-Shinozaki K (2003) Interaction between two cis-acting elements, ABRE and DRE, in ABA-dependent expression of Arabidopsis rd29A gene in response to dehydration and high-salinity stresses. Plant J 34:137–148Okamoto M, Kuwahara A, Seo M, Kushiro T, Asami T, Hirai N (2006) CYP707A1 and CYP707A2, which encode abscisic acid 8′-hydroxylases, are indispensable for proper control of seed dormancy and germination in Arabidopsis. Plant Physiol 141:97–107. doi: 10.1104/pp.106.079475.1Okamoto M, Peterson FC, Defries A, Park S-Y, Endo A, Nambara E, Volkman BF, Cutler SR (2013) Activation of dimeric ABA receptors elicits guard cell closure, ABA-regulated gene expression, and drought tolerance. Proc Natl Acad Sci USA 110:12132–12137. doi: 10.1073/pnas.1305919110Priest DM, Ambrose SJ, Vaistij FE, Elias L, Higgins GS, Ross ARS, Abrams SR, Bowles DJ (2006) Use of the glucosyltransferase UGT71B6 to disturb abscisic acid homeostasis in Arabidopsis thaliana. Plant J 46:492–502. doi: 10.1111/j.1365-313X.2006.02701.xRitchie M, Phipson B, Wu D, Hu Y, Law C, Shi W, Smyth G (2015) Limma powers differential expression analyses for RNA-sequencing and microarray studies. Nucleic Acids Res 43:e47Rodríguez-Gamir J, Ancillo G, González-Mas MC, Primo-Millo E, Iglesias DJ, Forner-Giner MA (2011) Root signalling and modulation of stomatal closure in flooded citrus seedlings. Plant Physiol Biochem 49:636–645. doi: 10.1016/j.plaphy.2011.03.003Romero P, Lafuente MT, Rodrigo MJ (2012a) The Citrus ABA signalosome: identification and transcriptional regulation during sweet orange fruit ripening and leaf dehydration. 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Cell 126:1023–1025. doi: 10.1016/j.cell.2006.09.001Seiler C, Harshavardhan VT, Rajesh K, Reddy PS, Strickert M, Rolletschek H, Scholz U, Wobus U, Sreenivasulu N (2011) ABA biosynthesis and degradation contributing to ABA homeostasis during barley seed development under control and terminal drought-stress conditions. J Exp Bot 62:2615–2632. doi: 10.1093/jxb/erq446Shimamura S, Yoshioka T, Yamamoto R, Hiraga S, Nakamura T, Shimada S, Komatsu S (2014) Role of abscisic acid in flood-induced secondary aerenchyma formation in soybean (Glycine max) hypocotyls. Plant Prod Sci 17:131–137. doi: 10.1626/pps.17.131Szostkiewicz I, Richter K, Kepka M, Demmel S, Ma Y, Korte A, Assaad FF, Christmann A, Grill E (2010) Closely related receptor complexes differ in their ABA selectivity and sensitivity. 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CONDUCTANCIA HIDRÁULICA EN PATRONES DE CÍTRICOS

La conductancia hidráulica determina la capacidad de transporte de agua afectando a las relaciones hídrias de la planta así como a la eficiencia de absorción de agua y nutrientes. Los patrones de cítricos difieren en su conductancia hidráulica debido a diferencias en la anatomía de los elementos vasculares o en la distribución del sistema radical pudiendo ser el principal factor que regula el desarrollo de los frutos y la respuesta de la planta a situaciones de estrés. Las relaciones hídricas pueden verse alteradas por estreses abióticos como el déficit hídrico, la salinidad o la asfixia radical. Recientes estudios realizados en especies no cítricas demuestran que las acuaporinas intervienen de manera importante en las relaciones hídricas de la planta y que los estímulos ambientales pueden regular su expresión. Ésta, a su vez, puede estar regulada por el pH citosólico. Por tanto, el principal objetivo de la presente tesis fue estudiar la conductancia hidráulica de los patrones de cítricos, determinando su influencia en la transpiración, los factores que la regulan y su papel en la respuesta de la planta a las situaciones de estrés abiótico. En los ensayos realizados, se utilizaron distintos patrones injertados y sin injertar. Se observaron diferencias en la capacidad de absorción de agua de los diferentes patrones, la cual tuvo una marcada influencia en el proceso de transpiración de la planta. La conductancia hidráulica se relacionó tanto con la expresión de acuaporinas como con la anatomía del xilema. Por otra parte, en condiciones de estrés hídrico se demostró que las características hidráulicas del patrón pueden determinar el grado de tolerancia de la planta a este estrés. Al someter las plantas a estrés salino se observó que la diferencia en la expresión de acuaporinas entre genotipops de cítricos afecta a la exclusión de cloruro de las hojas, determinando así su tolerancia a la salinidad. Por último, en condiciones de asfixia radical se demostró que lRodríguez Gamir, J. (2012). CONDUCTANCIA HIDRÁULICA EN PATRONES DE CÍTRICOS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/17838Palanci