title: Isolation and characterization of two YUCCA flavin monooxygenase genes from cultivated strawberry (Fragaria × ananassa Duch.).
abstract: In strawberry (Fragaria × ananassa Duch.), auxin has been recognized as the main signal molecule coordinating the growth and initiation of ripening of fruits. The molecular mechanism regulating auxin biosynthesis in strawberry remains unknown. This project reports two YUCCA flavin monooxygenase genes FaYUC1-2 isolated from cultivated strawberry. FaYUC1 and FaYUC2 are most homologous to AtYUC6 and AtYUC4, respectively. Significant expression of FaYUC1-2 is found in vegetative meristems and reproductive organs, with overlapping but distinct patterns. During fruit development, both transcripts of FaYUC1 and FaYUC2 in achenes reach a peak around large green fruit (G2) stage, but the sudden rise in FaYUC2 transcript level is much steeper and begins earlier than that in FaYUC1. FaYUC2 is also obviously expressed in the receptacles from green fruits, hinting another auxin source for receptacle development, other than achenes. FaYUC1 over-expression Arabidopsis exhibits typical auxin hyper-accumulation phenotype in many aspects, such as the narrow and downward curled leaves, strong apical dominance, short and hairy root. It is also severely sterile, due to the disruption of floral meristems initiation and floral organs development. Transgenic analysis indicates that strawberry YUC gene may hold conserved role in auxin biosynthesis like their homologs in other plants. Integrated with the spatiotemporal expression features, these results led us to propose that FaYUC1-2 may involve in many developmental processes including flower and fruit development in strawberry.
  
  
  CONCLUSIONS
  This paper is the first report of isolation and characterization of strawberry auxin biosynthesis genes. And their conserved functions in auxin biosynthesis were confirmed after ectopic expression.
authors.affiliation: College of Horticultural Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.forename: Yang-Yang
authors.initials: YY
authors.lastname: Ying
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Qing-Hua
authors.initials: QH
authors.lastname: Gao
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zhang
authors.forename: Jing-Gui
authors.initials: JG
authors.lastname: Fang
authors.forename: Ke
authors.initials: K
authors.lastname: Duan
mesh_terms: D000383:Agriculture; D000595:Amino Acid Sequence; D003433:Crosses, Genetic; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D005415:Flavins / Q000378:metabolism*; D031985:Fragaria / Q000201:enzymology* / Q000235:genetics* / Q000528:radiation effects; D005638:Fruit / Q000235:genetics / Q000254:growth & development / Q000528:radiation effects; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D017343:Genes, Plant / Q000235:genetics*; D007210:Indoleacetic Acids / Q000378:metabolism; D008027:Light; D006899:Mixed Function Oxygenases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010641:Phenotype; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000528:radiation effects; D040681:Structural Homology, Protein; D013997:Time Factors
chemical_list: D018076:DNA, Complementary; D005415:Flavins; D007210:Indoleacetic Acids; D012333:RNA, Messenger; D006899:Mixed Function Oxygenases