Hormonal and Nutritional Changes in the Flavedo Regulating Rind Color Development in Sweet Orange [Citrus sinensis (L.) Osb.]

The objective of this research was to determine the changes in the levels of endogenous gibberellins GA(1) and GA(4), abscisic acid (ABA), and ethylene during fruit coloring of on-tree fruits of sweet orange. The time course of carbohydrates and nitrogen content in the flavedo prior to fruit color break and during peel ripening were also studied. To identify nutritional and hormonal changes in the fruit, 45 days before fruit color break the peduncles of 15-30 fruits per tree of 'Washington' navel, 'Navelate,' and 'Valencia Delta Seedless' sweet orange, located in single-fruited shoots, were girdled to intercept phloem transport. A set of 15-30 fruits per tree remained intact on the peduncle for control. Girdling significantly delayed fruit coloration for more than 2 months; the delay paralleled higher GA(1) and GA(4) concentrations in the flavedo and retarded the rise of ABA concentration prior to color break. Girdling also reduced carbohydrate concentrations and increased N concentrations in the flavedo compared to control fruits; no ethylene production was detected. Therefore, in sweet orange, fruit changes color by reducing active gibberellin concentrations in the flavedo, which are involved in regulating sugars and ABA accumulation and in reducing N fraction concentration as rind color develops. This was demonstrated in vivo without removing the fruit from the tree. Comparable results were obtained with experiments carried out over four consecutive years in two countries (Spain and Uruguay).This study was partially supported by the Programme ALssan, EU Programme of High Level Scholarships for Latin America (IN E03D15012UR), and Comision Sectorial de Investigacion Cientifica (Univ. de la Republica, Uruguay). The authors thank Dra. D, Westall (UPV, Spain) for revising the manuscript.Gambetta Romaso, MG.; Martinez Fuentes, A.; Bentancur, O.; Mesejo Conejos, C.; Reig Valor, C.; Gravina, A.; Agustí Fonfría, M. (2012). Hormonal and Nutritional Changes in the Flavedo Regulating Rind Color Development in Sweet Orange [Citrus sinensis (L.) Osb.]. Journal of Plant Growth Regulation. 31(3):273-282. doi:10.1007/s00344-011-9237-5S273282313Agustí M, Almela V, Guardiola JL (1988) Aplicaciones de ácido giberélico para el control de alteraciones de la corteza de las mandarinas asociadas a la maduración. Invest Agr Prod Prot Veg 3:125–137Agustí J, Zapater M, Iglesias DJ, Cercós M, Tadeo FM, Talón M (2007) Differential expression of putative 9-cis-epoxycarotene dioxygenases and abscisic acid accumulation in water stressed vegetative and reproductive tissues of citrus. Plant Sci 172:85–94Aharoni Y (1968) Respiration of oranges and grapefruit harvested at different stages of development. Plant Physiol 43:99–102Alós E, Cercós M, Rodrigo MJ, Zacarías L, Talón M (2006) Regulation of color break in Citrus fruits. Changes in pigment profiling and gene expression induced by gibberellins and nitrate, two ripening retardants. J Agric Food Chem 54:4888–4895AOAC (2005) Official methods of analysis of the association of official analytical chemists, 14th edn. AOAC, Arlington, pp 611–613Aung LH, Houck LG, Norman SM (1991) The abscisic acid content of Citrus with special reference to lemons. J Exp Bot 42:1083–1088Beljaars PR, van Dijk R, van Der Horst GM (1994) Determination of nitrate in vegetables by continuous flow: interlaboratory study. J AOAC Int 77:1522–1529Chiwocha SDS, Abrams SR, Ambrose SJ, Cutler AJ, Loewen M, Ross ARS, Kermode AR (2003) A method for profiling classes for plant hormones and their metabolites using liquid chromatography-electrospray ionization tandem mass spectrometry: an analysis of hormones regulation of thermodormancy of lettuce (Lactuca sativa L.) seeds. Plant J 35:405–417Coggins CW Jr (1981) The influence of exogenous growth regulators on rind quality and internal quality of Citrus fruits. Proc Int Soc Citriculture 1:214–216Eaks IL (1970) Respiratory response, ethylene production, and response to ethylene of citrus fruit during ontogeny. Plant Physiol 45:334–338El-Otmani M, Lovatt CJ, Coggins CW Jr, Agusti M (1995) Plant growth regulators in citriculture: factors regulating endogenous levels in citrus tissues. Crit Rev Plant Sci 14:367–412El-Otmani M, Coggins CW Jr, Agusti M, Lovatt C (2000) Plant growth regulators in citriculture: world current uses. Crit Rev Plant Sci 19:395–447Fidelibus MW, Koch KE, Davies FS (2008) Gibberellic acid alters sucrose, hexoses, and their gradients in peel tissues during color break delay in ‘Hamlin’ orange. J Am Soc Hortic Sci 133:760–767Fujii H, Shimada T, Sugiyama A, Nishikawa F, Endo T, Nakano M, Ikoma Y, Shimizu T, Omura M (2007) Profiling ethylene-responsive genes in mature mandarin fruit using a citrus 22 K oligoarray. Plant Sci 173:340–348Fujii H, Shimada T, Sugiyama A, Endo T, Nishikawa F, Nakano M, Ikoma Y, Shimizu T, Omura M (2008) Profiling gibberellin (GA3)-responsive genes in mature mandarin fruit using a citrus 22 K oligoarray. Sci Hortic 116:291–298García-Luis A, Agustí M, Almela V, Romero V, Guardiola JL (1985) Effect of gibberellic acid on ripening and peel puffing in Satsuma mandarin. Sci Hortic 27:75–86García-Luis A, Fornés F, Guardiola JL (1986) Effects of gibberellin A3 and cytokinins on natural and post-harvest, ethylene-induced pigmentation of Satsuma mandarin peel. Physiol Plant 68:271–274Holland N, Sala JM, Menezes HC, Lafuente MT (1999) Carbohydrate content and metabolism as related to maturity and chilling sensitivity of cv. Fortune mandarins. J Agric Food Chem 47:2513–2518Huff A (1983) Nutritional control of regreening and degreening in Citrus peel segments. Plant Physiol 73:243–249Huff A (1984) Sugar regulation of plastid interconversions in the epicarp of Citrus fruit. Plant Physiol 76:307–312Iglesias DJ, Tadeo FR, Legaz F, Primo-Millo E, Talón M (2001) In vivo sucrose stimulation of color change in citrus fruit epicarps: interactions between nutritional and hormonal signals. Physiol Plant 112:244–250Jones WW, Embleton TW (1959) The visual effect of nitrogen nutrition on fruit quality of ‘Valencia’ oranges. Proc Am Soc Hortic Sci 73:234–236Katz E, Martínez-Lagunes P, Riov J, Weiss D, Goldschmidt EE (2004) Molecular and physiological evidence suggests the existence of a system II-like pathway of ethylene production in non-climacteric Citrus fruit. Planta 219:243–252Kuraoka T, Iwasaki K, Ishii T (1977) Effects of GA3 on puffing and levels of GA3-like substances and ABA in the peel of Satsuma mandarin (Citrus unshiu Marc.). J Am Soc Hortic Sci 102:651–654Lafuente MT, Martínez TM, Zacarías L (1997) Abscisic acid in the response of Fortune mandarins to chilling. Effect of maturity and high-temperature conditioning. J Sci Food and Agric 73:494–502Lee LS, Chapman JC (1988) Yield and fruit quality responses of Ellendale mandarins to different nitrogen and potassium fertiliser rates. Aust J Exp Agric 28:143–148Lewis LN, Coggins CW Jr (1964) The inhibition of carotenoid accumulation in navel oranges by gibberellin A3, as measured by thin layer chromatography. Plant Cell Physiol 5:457–463Lewis LN, Coggins CW Jr, Labanauskas CK, Dugger WM Jr (1967) Biochemical changes associated with natural and gibberellin A3 delayed senescence in the navel orange rind. Plant Cell Physiol 8:151–160Pons J, Almela V, Juan M, Agustí M (1992) Use of ethephon to promote color development in early ripening clementine cultivars. Proc Int Soc Citriculture 1:459–462Porat R, Weiss B, Cohen L, Daus A, Goren R, Droby S (1999) Effects of ethylene and 1-methylcyclopropene on the postharvest qualities of ‘Shamouti’ oranges. Postharvest Biol Technol 15:155–163Quiñones A, González MC, Montaña C, Primo-Millo E, Legaz F (2004) Fate and uptake efficiency of 15N applied with different seasonal distributions in Citrus trees. Proc Int Soc Citriculture 2:587–592Raigón MD, Pérez-García M, Maquieira A, Puchades R (1992) Determination of available nitrogen (nitric and ammoniacal) in soils by flow injection analysis. Analysis 20:483–487Rasmussen GK (1973) The effect of growth regulators on degreening and regreening of citrus fruit. Acta Hortic 34:473–478Richardson GR, Cowan AK (1995) Abscisic acid content of Citrus flavedo in relation to color development. J Hortic Sci 70:769–773Rivas F, Erner Y, Alós E, Juan M, Almela V, Agustí M (2006) Girdling increases carbohydrate availability and fruit-set in citrus cultivars irrespective of parthenocarpic ability. J Hortic Sci Biotechnol 81:289–295Rodrigo MJ, Zacarias L (2007) Effect of postharvest ethylene treatment on carotenoid accumulation and the expression of carotenoid biosynthetic genes in the flavedo of orange (Citrus sinensis L. Osbeck) fruit. Postharvest Biol Technol 43(1):14–22Rodrigo MJ, Marcos JF, Alférez F, Mallent MD, Zacarias L (2003) Characterization of pinalate, a novel Citrus sinensis mutant with a fruit-specific alteration that results in yellow pigmentation and decreased ABA content. J Exp Bot 54:727–738Rodrigo MJ, Alquezar B, Zacarias L (2006) Cloning and characterization of two 9-cis-epoxycarotene dioxygenase genes, differentially regulated during fruit maturation and under stress conditions, from orange (Citrus sinensis L. Osbeck). J Exp Bot 57:633–643Sala JM, Cuñat P, Collado M, Moncholi V (1992) Effect of nitrogenous fertilization (quantity and nitrogen form) in precocity of color change of ‘Navelina’ oranges. Proc Int Soc Citriculture 1:598–602Serek M, Tamari G, Sisler EC, Borochov A (1995) Inhibition of ethylene-induced cellular senescence symptoms by 1-methylcyclopropene, a new inhibitor of ethylene action. Physiol Plant 94:229–232Talón M, Hedden P, Primo-Millo E (1990) Gibberellins in Citrus sinensis: a comparison between seeded and seedless varieties. J Plant Growth Regul 9:201–206Trebitsh T, Goldschmidt EE, Riov J (1993) Ethylene induces de novo synthesis of chlorophyllase, a chlorophyll degrading enzyme, in Citrus fruit peel. Proc Nat Acad Sci U S A 90:9441–9445Walker-Simmons M (1987) ABA levels and sensitivity in developing wheat embryos of sprouting resistant and susceptible cultivars. Plant Physiol 84:61–66Weiler EW (1979) Use of immunoassay in plant science 7. Radioimmuoassay for the determination of free and conjugated abscisic-acid. Planta 144:255–263Win TO, Srilaong V, Kyu KL, Poomputsa K, Kanlayanarat S (2006) Biochemical and physiological changes during chlorophyll degradation in lime (Citrus aurantifolia Swingle cv. ‘Paan’). J Hortic Sci Biotechnol 81:471–477Zacarías L, Talón M, Ben CW, Lafuente MT, Primo-Millo E (1995) Abscisic acid increases in non-growing and paclobutrazol-treated fruits of seedless mandarins. Physiol Plant 95:613–61