title: Auxin biosynthesis by the YUCCA6 flavin monooxygenase gene in woodland strawberry.
abstract: Auxin has been regarded as the main signal molecule coordinating the growth and ripening of fruits in strawberry, the reference genomic system for Rosaceae. The mechanisms regulating auxin biosynthesis in strawberry are largely elusive. Recently, we demonstrated that two YUCCA genes are involved in flower and fruit development in cultivated strawberry. Here, we show that the woodland strawberry (Fragaria vesca L.) genome harbors nine loci for YUCCA genes and eight of them encode functional proteins. Transcription pattern in different plant organs was different for all eight FvYUCs. Functionality of the FvYUC6 gene was studied in transgenic strawberry overexpressing FvYUC6, which showed typical high-auxin phenotypes. Overexpression of FvYUC6 also delayed flowering and led to complete male sterility in F. vesca. Additionally, specific repression of FvYUC6 expression by RNA interference significantly inhibited vegetative growth and reduced plant fertility. The development of leaves, roots, flowers, and fruits was greatly affected in FvYUC6-repressed plants. Expression of a subset of auxin-responsive genes was well correlated with the changes of FvYUC6 transcript levels and free indole-3-acetic acid levels in transgenic strawberry. These observations are consistent with an important role of FvYUC6 in auxin synthesis, and support a main role of the gene product in vegetative and reproductive development in woodland strawberry.
authors.affiliation: Forestry and Fruit Tree Research Institute, Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai Academy of Agricultural Sciences (SAAS), Shanghai, 201403, China; Shanghai Key Laboratory of Agricultural Genetics and Breeding, Institute of Biotechnology, SAAS, Shanghai, 201106, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.forename: Wei-Fa
authors.initials: WF
authors.lastname: Xie
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Victoriano
authors.initials: V
authors.lastname: Valpuesta
authors.forename: Zheng-Wen
authors.initials: ZW
authors.lastname: Ye
authors.forename: Qing-Hua
authors.initials: QH
authors.lastname: Gao
authors.forename: Ke
authors.initials: K
authors.lastname: Duan
mesh_terms: D031985:Fragaria / Q000201:enzymology* / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D007210:Indoleacetic Acids; D010940:Plant Proteins; D006899:Mixed Function Oxygenases
keywords: Auxin biosynthesis; Fragaria vesca; RNA interference; YUCCA genes; plant development