Characterization of two fungal-elicitor-induced rice cDNAs encoding functional homologues of the rab-specific GDP-dissociation inhibitor

• Published in: Planta Vol. 210; no. 1; pp. 143 - 149
• Main Authors: Kim, W.Y, Kim, C.Y, Cheong, N.E, Choi, Y.O, Lee, K.O, Lee, S.H, Park, J.B, Nakano, A, Bahk, J.D, Cho, M.J
• Format: Journal Article
• Language: English
• Published: Berlin Springer-Verlag 01.11.1999; Springer
• Subjects: amino acid sequences; Animals; Biological and medical sciences; Cattle; cell suspension culture; Cloning, Molecular; Complementary DNA; DNA probes; DNA, Complementary; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Fungal Proteins - genetics; genbank/af016896; genbank/af016897; gene expression; Genes; genetic complementation; Guanine nucleotide dissociation inhibitors; Guanine Nucleotide Dissociation Inhibitors - genetics; guanosine diphosphate; infection; inhibitors; Magnaporthe grisea; Messenger RNA; Molecular Sequence Data; mutants; nucleotide sequences; oligosaccharides; Oryza - genetics; Oryza sativa; Pathology, epidemiology, host-fungus relationships. Damages, economic importance; Phytopathology. Animal pests. Plant and forest protection; Plasmids; polymerase chain reaction; rab3A GTP-Binding Protein - metabolism; recombinant proteins; Rice; RNA; RNA, Messenger - genetics; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Synaptic Membranes - metabolism; Ungulates; Yeasts; Monocotyledones; Plant pathogen; Host agent relation; Elicitor; Structure function relationship; Cereal crop; Fungi; Characterization; Infection; Binding protein; Oryza sativa; Signal transduction; Gene; Gramineae; Angiospermae; Defense mechanism; Ascomycetes; Spermatophyta; Inhibition; Thallophyta
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/s004250050663

By using the mRNA differential display approach to isolate defense signaling genes active at the early stage of fungal infection two cDNA fragments with high sequence homology to rab-specific GDP-dissociation inhibitors (GDIs) were identified in rice (Oryza sativa L.) suspension cells. Using polymerase-chain-reaction products as probes, two full-length cDNA clones were isolated from a cDNA library of fungal-elicitor-treated rice, and designated as OsGDII and OsGDI2. The deduced amino acid sequences of the isolated cDNAs exhibited substantial homology to Arabidopsis rab-GDIs. Northern analysis revealed that transcripts detected with the 3'-gene-specific DNA probes accumulated to high levels within 30 min after treatment with a fungal elicitor derived from Magnaporthe grisea. The functionality of the OsGDIs was demonstrated by their ability to rescue the Sec19 mutant of Saccharomyces cerevisiae which is defective in vesicle transport. The proteins, expressed in Escherichia coli, cross-reacted with a polyclonal antibody prepared against bovine rab-GDI. Like bovine rab-GDI, the OsGDI proteins efficiently dissociated rab3A from bovine synaptic membranes. Using the two-hybrid system, it was shown that the OsGDIs specifically interact with the small GTP-binding proteins belonging to the rab subfamily. The specific interaction was also demonstrated in vitro by glutathione S-transferase resin pull-down assay.