title: ABA-mediated heterophylly is regulated by differential expression of 9-cis-epoxycarotenoid dioxygenase 3 in lilies.
abstract: Although exogenous ABA-regulated heterophylly has been well documented in multiple plant species, the effect of endogenous ABA and its molecular mechanism remain uncharacterized. In the present study, the effects of endogenous ABA on heterophyllous switching were investigated in two different lily varieties, Lilium formosanum and Lilium oriental hybrid 'Casa Blanca'. Seedlings of L. formosanum, which have scale-leaf-type growth, displayed low levels of both 9-cis-epoxycarotenoid dioxygenase 3 (LfNCED3) transcripts and ABA, whereas seedlings of L. oriental hybrid 'Casa Blanca', which have scale-type growth, displayed high levels of both LoNCED3 transcripts and ABA. Sucrose induced endogenous ABA production in cultured lilies; low ABA induction shows scale-leaf-type growth, whereas scale-type growth becomes predominant when ABA levels are high. Heterologous expression of either LfNCED3 or LoNCED3 was found to complement the Arabidopsis Atnced3 mutant. Interestingly, the expression patterns of LfNCED3 and LoNCED3 in transgenic Arabidopsis plants are distinguishable. Further promoter analysis revealed that a putative E2F-like element in the LfNCED3 promoter, but not in the LoNCED3 promoter, plays a negative role in controlling its activity. Collectively, our results demonstrate that NCED3 plays a key role in ABA-mediated heterophylly in lilies.
authors.affiliation: Department of Horticulture, National Taiwan University, Taipei, Taiwan.
authors.forename: Hung-Chi
authors.initials: HC
authors.lastname: Chen
authors.forename: San-Gwang
authors.initials: SG
authors.lastname: Hwang
authors.forename: Shiau-Ming
authors.initials: SM
authors.lastname: Chen
authors.forename: Chou-Tou
authors.initials: CT
authors.lastname: Shii
authors.forename: Wan-Hsing
authors.initials: WH
authors.lastname: Cheng
mesh_terms: D000040:Abscisic Acid / Q000096:biosynthesis / Q000494:pharmacology*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D049308:Dioxygenases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D017343:Genes, Plant / Q000235:genetics; D027762:Lilium / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D008954:Models, Biological; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000187:drug effects / Q000235:genetics; D009928:Organ Specificity / Q000187:drug effects / Q000235:genetics; D010641:Phenotype; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology* / Q000502:physiology*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics; D013395:Sucrose / Q000494:pharmacology
chemical_list: D010940:Plant Proteins; D013395:Sucrose; D000040:Abscisic Acid; D049308:Dioxygenases; C109043:9-cis-epoxy-carotenoid dioxygenase