title: Identification and characterization of the defensin-like gene family of grapevine.
abstract: Defensins are a class of small and diverse cysteine-rich proteins found in plants, insects, and vertebrates, which share a common tertiary structure and usually exert broad-spectrum antimicrobial activities. We used a bioinformatic approach to scan the Vitis vinifera genome and identified 79 defensin-like sequences (DEFL) corresponding to 46 genes and allelic variants, plus 33 pseudogenes and gene fragments. Expansion and diversification of grapevine DEFL has occurred after the split from the last common ancestor with the genera Medicago and Arabidopsis. Grapevine DEFL localization on the 'Pinot Noir' genome revealed the presence of several clusters likely evolved through local duplications. By sequencing reverse-transcription polymerase chain reaction products, we could demonstrate the expression of grapevine DEFL with no previously reported record of expression. Many of these genes are predominantly or exclusively expressed in tissues linked to plant reproduction, consistent with findings in other plant species, and some of them accumulated at fruit ripening. The transcripts of five DEFL were also significantly upregulated in tissues infected with Botrytis cinerea, a necrotrophic mold, suggesting a role of these genes in defense against this pathogen. Finally, three novel defensins were discovered among the identified DEFL. They inhibit B. cinerea conidia germination when expressed as recombinant proteins.
authors.affiliation: IASMA Research and Innovation Centre, San Michele all'Adige, Italy.
authors.forename: Lisa
authors.initials: L
authors.lastname: Giacomelli
authors.forename: Valentina
authors.initials: V
authors.lastname: Nanni
authors.forename: Luisa
authors.initials: L
authors.lastname: Lenzi
authors.forename: Jun
authors.initials: J
authors.lastname: Zhuang
authors.forename: Mauro
authors.initials: M
authors.lastname: Dalla Serra
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Banfield
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Town
authors.forename: Kevin A T
authors.initials: KA
authors.lastname: Silverstein
authors.forename: Elena
authors.initials: E
authors.lastname: Baraldi
authors.forename: Claudio
authors.initials: C
authors.lastname: Moser
mesh_terms: D000595:Amino Acid Sequence; D020171:Botrytis / Q000472:pathogenicity; D023082:Defensins / Q000235:genetics*; D060467:Disease Resistance / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D027843:Vitis / Q000235:genetics* / Q000382:microbiology
chemical_list: D023082:Defensins; D011994:Recombinant Proteins