Eucalyptus has a functional equivalent of the Arabidopsis floral meristem identity gene LEAFY
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Two genes cloned from Eucalyptus globulus, Eucalyptus LeaFy (ELF1 and ELF2), have sequence homology to the floral meristem identity genes LEAFY from Arabidopsis and FLORICAULA from Antirrhinum. ELF1 is expressed in the developing eucalypt floral organs in a pattern similar to LEAFY while ELF2 appears to be a pseudo gene. ELF1 is expressed strongly in the early floral primordium and then successively in the primordia of sepals, petals, stamens and carpels. It is also expressed in the leaf primordia and young leaves and adult and juvenile trees.
The ELF1 promoter coupled to a GUS reporter gene directs expression in transgenic Arabidopsis in a temporal and tissue-specific pattern similar to an equivalent Arabidopsis LEAFY promoter construct. Strong expression is seen in young flower buds and then later in sepals and petals. No expression was seen in rosette leaves or roots of flowering plants or in any non-flowering plants grown under long days. Furthermore, ectopic expression of the ELF1 gene in transgenic Arabidopsis causes the premature conversion of shoots into flowers, as does an equivalent 35S-LFY construct. These data suggest that ELF1 plays a similar role to LFY in flower development and that the basic mechanisms involved in flower initiation and development in Eucalyptus are similar to those in Arabidopsis.
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- 1.Alvarez J, Guli CL, Yu X, Smyth DR: terminal flower: a gene affecting inflorescence development in Arabidopsis thaliana. Plant J 2: 103–116 (1992).Google Scholar
- 4.Carr DJ, Carr SGM: Natural groups within the genus Eucalyptus. In: Leeper GW (ed) The Evolution of Living Organisms, pp. 426–445. Melbourne University Press, Melbourne (1962).Google Scholar
- 7.Dennis ES, Gerlach WL, Pryor AJ, Bennetzen JL, Inglis A, Llewellyn DJ, Sachs MM, Ferl RA, Peacock WJ: Molecular analysis of the alochol dehydrogenase (Adh1) gene of maize. Nucl Acids Res. 12: 178–180 (1984).Google Scholar
- 10.Drinnan AN, Ladiges PY: Floral development in the ‘Symphomyrtus group’ of eucalypts (Eucalyptus: Myrtaceae). Aust Syst Bot 4: 553–562 (1991).Google Scholar
- 12.Harcourt R, Kyozuka J, Zhu X, Southerton S, Llewellyn D, Dennis E, Peacock J: Genetic engineering for sterility in temperate plantation eucalypts. In Potts BM, Borralho NMG, Reid JB, Cromer RN, Tibbits WN, Raymond CA (eds) Eucalypt Plantations: Improving Fibre Yield and Quality, pp. 403–405. Proceedings CRC-IUFRO Conference Hobart, 19–24 February 1995. CRC for Temperate Hardwood Forestry, Hobart, Australia (1995).Google Scholar
- 13.Hempel FD, Feldman LJ: Bi-directional inflorescence development in Arabidopsis thaliana: acropetal initiation of flowers and basipetal initiation of paraclades. Planta 192: 276–286 (1994).Google Scholar
- 16.Jefferson RA: Assaying chimeric genes in plants: the GUS gene system. Plant Mol Biol Rep 5: 387–405 (1987).Google Scholar
- 20.Mullins KV, Llewellyn DJ, Hartney VJ, Strauss S, Dennis ES: Regeneration and transformation of Eucalyptus camaldulensis. Plant Cell Rep 16: 787–791 (1997).Google Scholar
- 21.Pryor LD, Knox RB: Operculum development and evolution in eucalypts. Aust J Bot 19: 143–172 (1971).Google Scholar
- 22.Rottmann WH, Boes TK, Strauss SH: Structure and expression of a LEAFY homolog from Populus. J Cell Biochem (Suppl. 17B): 23 (1993).Google Scholar
- 23.Valvekens D, Van Montagu M, Van Lijsjebettens M: Agrobacterium tumefaciens-mediated transformation of Arabidopsis thaliana root explants by using kanamycin selection. Proc Natl Acad Sci USA 85: 5536–5540 (1988)Google Scholar
- 26.Weigel D, Myerowitz EM: Activation of floral homeotic genes in Arabidopsis. Science 261: 1723–1726 (1993).Google Scholar