[en] The involvement of nitrogenous substances in the transition to flowering was investigated in Sinapis alba and Arabidopsis thaliana (Columbia). Both species grown in short days (SD) are induced to flower by one long day (LD). In S. alba, the phloem sap (leaf and apical exudates) and the xylem sap (root exudate) were analysed in LD versus SD. In A. thaliana, only the leaf exudate could be analysed but an alternative system for inducing flowering without day-length extension was used: the displaced SD (DSD). Significant results are: (i) in both species, the leaf exudate was enriched in Gln during the inductive LD, at a time compatible with export of the floral stimulus; (ii) in S. alba, the root export of amino acids decreased in LD, whereas the nitrate remained unchanged - thus the extra-Gln found in the leaf exudate should originate from the leaves; (iii) extra-Gln was also found very early in the apical exudate of S. alba in LD, together with more Glu; (iv) in A. thaliana induced by one DSD, the leaf export of Asn increased sharply, instead of Gln in LD. This agrees with Asn prevalence in C-limited plants. The putative role of amino acids in the transition to flowering is discussed.
EC contract BI04 CT97-2231; Interuniversity Attraction Poles Programme P4/15
Funders :
DG RDT - Commission Européenne. Direction Générale de la Recherche et de l'Innovation [BE] BELSPO - Politique scientifique fédérale [BE] FRIA - Fonds pour la Formation à la Recherche dans l'Industrie et dans l'Agriculture [BE] F.R.S.-FNRS - Fonds de la Recherche Scientifique [BE] ULiège FSR - Université de Liège. Fonds spéciaux pour la recherche [BE]
Babin V., Bonnemain J.L. (1993) Variations saisonnières du pH et du contenu en acides aminés de la sève xylémienne de Populus x euramericana 1.214. Acta Botanica Galica 140:421-426.
Bernier G. (1969) Sinapis alba L. The Induction of Flowering Some Case Histories , (ed. L.T. Evans). MacMillan, Melbourne; 305-327.
Bernier G. (1989) Events of the floral transition of meristems. Plant Reproduction: from Floral Induction to Pollination , (eds E. Lord & G. Bernier). The American Society Of Plant Physiologists, Rockville, MD; 42-50.
Bernier G., Corbesier L., Périlleux C., Havelange A., Lejeune P. (1998) Physiological analysis of the floral transition. Genetic and Environmental Manipulation of Horticultural Crops , (eds K.E. Cockshull, D. Gray, G.B. Seymour & B. Thomas). CAB International, Wallingford, UK; 103-109.
Bernier G., Havelange A., Houssa C., Petitjean A., Lejeune P. (1993) Physiological signals that induce flowering. Plant Cell 5:1147-1155.
Bernier G., Kinet J.-M., Sachs R.M. The Physiology of Flowering, Vol I , CRC Press, Boca Raton, FL; 1981, 1.
Bouniols A., Delecolle M.-C., Kronenberger J., Margara J. (1973) Evolution de la composition en acides aminés libres des racines de chicorée dans différentes conditions assurant le développement végétatif ou floral des bourgeons. C R Académie des Sciences Paris 276:2797-2800.
Campbell W.H. (1999) Nitrate reductase structure, function and regulation: Bridging the gap between biochemistry and physiology. Annual Review of Plant Physiology and Plant Molecular Biology 50:277-303.
Corbesier L., Gadisseur I., Silvestre G., Jacqmard A., Bernier G. (1996) Design in Arabidopsis thaliana of a synchronous system of floral induction by one long day. Plant Journal 9:947-952.
Corbesier L., Lejeune P., Bernier G. (1998) The role of carbohydrates in the induction of flowering in Arabidopsis thaliana comparison between the wild type and a starchless mutant. Planta 206:131-137.
Einarsson S., Josefsson B., Lagerkvist S. (1983) Determination of amino acids with 9-fluorenylmethylchloroformate and reversephase high-performance liquid chromatography. Journal of Chromatography 282:609-618.
Kandeler R. (1985) Lemnaceae. Handbook of Flowering , (ed. A.H. Halevy). CRC Press, Boca Raton, FL; 3:251-279.
Kinet J.-M. (1975) Gross chemical changes occurring in the leaf of Sinapis alba during photoperiodic induction of flowering. New Phytologist 74:25-32.
King R.W., Zeevaart J.A.D. (1974) Enhancement of phloem exudation from cut petioles by chelating agents. Plant Physiology 53:96-103.
Koornneef M., Alonso-Blanco C., Peeters A.J.M., Soppe W. (1998) Genetic control of flowering time in Arabidopsis. Annual Review of Plant Physiology and Plant Molecular Biology 49:345-370.
Lam H.M., Coschigano K., Schultz C., Melo-Oliveira R., Tjaden G., Oliveira I., Ngai N., Hsieh M.H., Coruzzi G. (1995) Use of Arabidopsis mutants and genes to study amide amino acid biosynthesis. Plant Cell 7:887-898.
Lejeune P., Bernier G., Requier M.-C., Kinet J.-M. (1993) Sucrose increase during floral induction in the phloem sap collected at the apical part of the shoot of the long-day plant Sinapis alba L. Planta 190:71-74.
Lejeune P., Bernier G., Requier M.-C., Kinet J.-M. (1994) Cytokinins in phloem and xylem saps of Sinapis alba during floral induction. Physiologia Plantarum 90:522-528.
Lejeune P., Kinet J.-M., Bernier G. (1988) Cytokinin fluxes during floral induction in the long-day plant Sinapis alba L. Plant Physiology 86:1095-1098.
Levy Y.Y., Dean C. (1998) The transition to flowering. Plant Cell 10:1973-1989.
Maeng J., Khudairi A.K. (1973) Studies on the flowering mechanism in Lemna. I. Amino acid changes during flower induction. Physiologia Plantarum 28:264-270.
Peoples M.B., Gifford R.M. (1990) Long-distance transport of nitrogen and carbon from sources to sinks in higher plants. Plant Physiology Biochemistry and Molecular Biology , (eds D.T Dennis & D.H. Turpin). Longman, Harlow; 434-447.
Périlleux C., Bernier G., Kinet J.-M. (1994) Circadian rhythms and the induction of flowering in the long-day grass Lolium temulentum L. Plant, Cell and Environment 17:755-761.
Raper C.D.J., Thomas J.F., Tolley-Henry L., Rideout J.W. (1988) Assessment of an apparent relationship between availability of soluble carbohydrates and reduced nitrogen during floral initiation in tobacco. Botanical Gazette 149:289-294.
Rideout J.W., Raper C.D., Miner G.S. (1992) Changes in ratio of soluble sugars and free amino nitrogen in the apical meristem during floral transition of tobacco. International Journal of Plant Science 153:78-88.
Sachs R.M., Hackett W.P. (1977) Chemical control of flowering. Acta Horticldturae 68:29-49.
Samach A., Onouchi H., Gold S.E., Ditta G.S., Schwarz-Sommer Z., Yanofsky M.F., Coupland G. (2000) Distinct roles of CONSTANS target genes in reproductive development of Arabidopsis. Science 288:1613-1616.
Sauter J.J. (1981) Seasonal variation of amino acids and amides in the xylem sap of Salix. Zeitscrift für Pflanzenphysiology 101:399-411.
Scheible W.-R., Lauerer M., Schulze E.-D., Caboche M., Stitt M. (1997) Accumulation of nitrate in the shoot acts as a signal to regulate shoot-root allocation in tobacco. Plant Journal 11:671-691.
Shvedskaya Z.M., Kruzhilin A.S. (1966) Changes in proline content during vernalization and differentiation of the growth points in biennial and winter plants. Soviet Plant Physiology 13:948-955.
Stitt M. (1999) Nitrate regulation of metabolism and growth. Current Opinions in Plant Biology 2:178-186.
Tanaka O., Takimoto A. (1977) Flower-promoting effect of some amino acids and amides in Lemna paucicostata 6746. Plant and Cell Physiology 18:27-34.
Thorpe M.R., Minchin P.E.H. (1996) Mechanisms of long- and short-distance transport from sources to sinks. Photoassimilate Distribution in Plants and Crops: Source-Sink Relationships , (eds E. Zamski & A.A. Schaffer)Marcel Dekker, New York; 261-282.
Valle E.M., Boggio S.B., Heldt H.W. (1998) Free amino acid composition of phloem sap and growing fruit of Lycopersicon esculentum. Plant and Cell Physiology 39:458-461.
Vallée J.-C., Perdrizet E., Martin C. (1968) Les acides aminés libres chez Nicotiana xanthi n.c. en fonction du développement et de la température. Annales de Physiologie Végétale 10:237-250.
Vincent R., Fraisier V., Chaillou S., Limami M.A., Deleens E., Phillipson B., Douat C., Boutin J.-P., Hirel B. (1997) Overexpression of a soybean gene encoding cytosolic glutamine synthetase in shoots of transgenic Lotus corniculatus L. plants triggers changes in ammonium assimilation and plant development. Planta 201:424-433.
Weiner H., Blechschmidt-Schneider S., Mohme H., Eschrich W., Heldt H.W. (1991) Phloem transport of amino acids. Comparison of amino acid contents of maize leaves and of the sieve tube exudate. Plant Physiology and Biochemistry 29:19-23.
Winter H., Lohaus G., Heldt H.W. (1992) Phloem transport of amino acids in relation to their cytosolic levels in barley leaves. Plant Physiology 99:996-1004.
Zhang H., Jennings A., Barlow P.W., Forde B.G. (1999) Dual pathways for regulation of root branching by nitrate. Proceedings of the National Academy of Sciences of the USA 96:6529-6534.
Zhuo D., Okamoto M., Vidmar J.J., Glass A.D.M. (1999) Regulation of a putative high-affinity nitrate transporter (Nrt2; 1At) in roots of Arabidopsis thaliana. Plant Journal 17:563-568.