title: Characterization of expressed sequence tags from Lilium longiflorum in vernalized and non-vernalized bulbs.
abstract: In Lilium longiflorum, vernalization is both an obligatory requirement and the major factor affecting flowering time, however, little is known about the molecular regulation of this mechanism in Lilium and other flowering bulbs. Exposure of L. longiflorum bulbs to 9 weeks at 4°C greatly promoted stem elongation within the bulb, floral transition and flowering. Subtraction libraries of vernalized (V) and non-vernalized (NV) bulb meristems were constructed. 671 and 479 genes were sequenced, from which 72 and 82 proteins were inferred for the NV-V and the V-NV libraries, respectively. Much lower transcription levels and putative gene functions were recorded in the NV-V libraries compared the V-NV libraries. However, a large number of genes annotated to transposable elements (TEs), represented more than 20% of the sequenced cDNA were expressed in the NV-V libraries, as opposed to less than 2% in the V-NV libraries. The expression profile of several genes potentially involved in the vernalization pathway was assessed. Expression of LlSOC1, the lily homologue of SUPPRESSOR OF OVER-EXPRESSION OF CO1 (SOC1), an important flowering gene in several plant species, found in the V-NV library, was highly up-regulated during bulb meristem cold exposure. The subtraction libraries provided a fast tool for relevant gene isolation.
authors.affiliation: Department of Life Sciences, Ben Gurion University of the Negev, P.O. Box 653, Beersheva 84105, Israel. Electronic address: lugassim@gmail.com.
authors.forename: Maya
authors.initials: M
authors.lastname: Lugassi-Ben Hamo
authors.affiliation: Genetwister Technologies B.V., P.O. Box 193, 6700 AD Wageningen, The Netherlands. Electronic address: c.villacortamartin@genetwister.nl.
authors.forename: Carlos Villacorta
authors.initials: CV
authors.lastname: Martin
authors.affiliation: Department of Life Sciences, Ben Gurion University of the Negev, P.O. Box 653, Beersheva 84105, Israel. Electronic address: mzaccai@bgu.ac.il.
authors.forename: Michele
authors.initials: M
authors.lastname: Zaccai
mesh_terms: D018076:DNA, Complementary / Q000235:genetics; D020224:Expressed Sequence Tags; D035264:Flowers / Q000235:genetics / Q000502:physiology; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D027762:Lilium / Q000235:genetics* / Q000502:physiology; D018519:Meristem / Q000235:genetics / Q000502:physiology; D058977:Molecular Sequence Annotation; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics*; D018517:Plant Roots / Q000235:genetics / Q000502:physiology; D018547:Plant Stems / Q000235:genetics / Q000502:physiology; D017422:Sequence Analysis, DNA; D066251:Subtractive Hybridization Techniques
chemical_list: D018076:DNA, Complementary; D010940:Plant Proteins
keywords: ESTs; Flowering; Lilium longiflorum; Meristem; Subtraction libraries; Vernalization