title: Characterization of three linalool synthase genes from Citrus unshiu Marc. and analysis of linalool-mediated resistance against Xanthomonas citri subsp. citri and Penicilium italicum in citrus leaves and fruits.
abstract: Three cDNA clones from Satsuma mandarin (Citrus unshiu Marc.) were isolated and expressed in Escherichia coli. CuSTS3-1 and CuSTS3-2 encode linalool synthases and CuSTS4 encodes a nerolidol/linalool synthase. Transcripts of CuSTS3-1, CuSTS3-2 and CuSTS4 were abundant in young fruit at 60 days after flowering (DAF), flowers and leaves, respectively. Treatments with Xanthomonas citri subsp. citri (XCC), the causal agent of citrus canker and Penicillium italicum (PI), the cause of post-harvest fruit decay, and wounding up-regulated CuSTS3-1 in fruit and mainly CuSTS4 in leaves. Linalool, citral, geraniol and citronellol showed strong antibacterial and antifungal activities against XCC and PI in vitro, while most other mono-and sesquiterpenes, including limonene and gamma-terpinene, did not. Linalool, used at levels similar to those present in resistant Ponkan mandarin (Citrus reticulata Blanco) leaves, was able to inhibit growth of XCC in vitro. Compared to other five citrus types, linalool accumulated at extraordinarily high levels in Ponkan mandarin leaves and was released at high amounts from their leaves, while it was hardly detectable in the most susceptible species, indicating that linalool biosynthesis and accumulation might be involved in plant defense against bacterial and fungal pathogens and be associated with field resistance to citrus canker.
authors.affiliation: National Institute of Fruit Tree Science (NIFTS), National Agriculture and Bio-oriented Research Organization (NARO), Sizuoka, Shizuoka 424-0292, Japan. Electronic address: tshimada@affrc.go.jp.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Shimada
authors.affiliation: National Institute of Fruit Tree Science (NIFTS), National Agriculture and Bio-oriented Research Organization (NARO), Sizuoka, Shizuoka 424-0292, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Endo
authors.affiliation: National Institute of Fruit Tree Science (NIFTS), National Agriculture and Bio-oriented Research Organization (NARO), Sizuoka, Shizuoka 424-0292, Japan. Electronic address: hfujii@affrc.go.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujii
authors.affiliation: Fundecitrus, Av. Dr. Adhemar de Barros Pereira, 201, 14807-040 Vila Melhado, Araraquara, Sao Paulo, Brazil; Instituto de Biología Molecular y Celular de Plantas (IBMCP/CSIC-UPV), Ingeniero Fausto Elio, Valencia 46022, Spain. Electronic address: anrodbai@ibmcp.upv.es.
authors.forename: Ana
authors.initials: A
authors.lastname: Rodríguez
authors.affiliation: Fundecitrus, Av. Dr. Adhemar de Barros Pereira, 201, 14807-040 Vila Melhado, Araraquara, Sao Paulo, Brazil; Instituto de Biología Molecular y Celular de Plantas (IBMCP/CSIC-UPV), Ingeniero Fausto Elio, Valencia 46022, Spain. Electronic address: lpenya@fundecitrus.com.br.
authors.forename: Leandro
authors.initials: L
authors.lastname: Peña
authors.affiliation: Faculty of Agriculture, Shizuoka University, Sizuoka, Shizuoka 422-8529, Japan. Electronic address: amomura@ipc.shizuoka.ac.jp.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Omura
mesh_terms: D000080462:Acyclic Monoterpenes; D000595:Amino Acid Sequence; D015139:Blotting, Southern; D002957:Citrus / Q000201:enzymology* / Q000235:genetics / Q000382:microbiology; D060467:Disease Resistance / Q000235:genetics* / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D005091:Exons / Q000235:genetics; D035264:Flowers / Q000235:genetics / Q000382:microbiology; D005638:Fruit / Q000235:genetics / Q000382:microbiology*; D008401:Gas Chromatography-Mass Spectrometry; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D006836:Hydro-Lyases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D007438:Introns / Q000235:genetics; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D039821:Monoterpenes / Q000494:pharmacology*; D010407:Penicillium / Q000187:drug effects* / Q000502:physiology; D010802:Phylogeny; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D018515:Plant Leaves / Q000235:genetics / Q000382:microbiology*; D015854:Up-Regulation / Q000235:genetics; D014974:Xanthomonas / Q000187:drug effects*
chemical_list: D000080462:Acyclic Monoterpenes; D039821:Monoterpenes; C018584:linalool; D006836:Hydro-Lyases; C092055:S-linalool synthase
keywords: Linalool, Citrus, Xanthomonas citri, Penicillium italicum, Antibacterial, Antifungal