PR-1 gene family of grapevine: a uniquely duplicated PR-1 gene from a Vitis interspecific hybrid confers high level resistance to bacterial disease in transgenic tobacco.
A functional contribution of pathogenesis-related 1 (PR-1) proteins to host defense has been established. However, systematic investigation of the PR-1 gene family in grapevine (Vitis spp.) has not been conducted previously. Through mining genomic databases, we identified 21 PR-1 genes from the Vitis vinifera genome. Polypeptides encoded by putative PR-1 genes had a signal sequence of about 25 residues and a mature protein of 10.9-29 kDa in size. PR-1 mature proteins contained a highly conserved six-cysteine motif and pI values ranging from 4.6 to 9. A major cluster with 14 PR-1 genes was mapped to a 280-kb region on chromosome 3. One particular PR-1 gene within the cluster encoding a basic-type isoform (pI 7.77), herein named VvPR1b1, was isolated from various genotypes of grapevine (Vitis spp.) for functional studies. Sequence analysis of PCR-amplified DNA revealed that all genotypes contained a single VvPR1b1 gene except for a broad-spectrum bacterial and fungal disease resistant Florida bunch grape hybrid, 'BN5-4', from which seven different homologues were identified. Duplication of VvPR1b1-related genes encoding acidic-type PR-1 isoforms was also observed among several genotypes. However, transgenic expression analysis of grapevine PR-1 genes under strong constitutive promoters in transgenic tobacco revealed that only the basic-type VvPR1b1 gene duplicated in 'BN5-4' was capable of conferring high level resistance to bacterial disease caused by Pseudomonas syringae pv. tabaci.
Grape Biotechnology Core Laboratory, Mid-Florida Research and Education Center, University of Florida/IFAS, 2725 Binion Road, Apopka, FL 32703-8504, USA.
Zhijian T
ZT
Li
Sadanand A
SA
Dhekney
Dennis J
DJ
Gray
D000595:Amino Acid Sequence; D018628:Gene Dosage; D018506:Gene Expression Regulation, Plant; D020131:Genes, Duplicate / Q000235:genetics*; D017343:Genes, Plant / Q000235:genetics; D005838:Genotype; D006824:Hybridization, Genetic; D007113:Immunity, Innate / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D010455:Peptides / Q000737:chemistry; D010802:Phylogeny; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology* / Q000382:microbiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D016133:Polymerase Chain Reaction; D044224:Pseudomonas syringae / Q000502:physiology; D015203:Reproducibility of Results; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D013045:Species Specificity; D014026:Nicotiana / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D027843:Vitis / Q000235:genetics*
D010455:Peptides; D010940:Plant Proteins