Transgenic potato plants expressing osmotin gene inhibits fungal development in inoculated leaves.
Osmotin, a 24-KD protein isolated from Nicotiana tabacum 'Xanthi nc' was very toxic to Phytophthora infestans in vitro assay. Transgenic potato plants expressing wild osmotin protein delayed the emergence of symptoms of disease. Two osmotin mutants have been produced by PCR mutagenesis. One mutant, delta C18 osmotin, had a nonsense mutation near the C-terminus that deleted the carboxyl terminal prepropeptide (CTPP) of 18 amino acids. Another mutant, osmotin-P, had amber mutation at 96th amino acid. Both mutant genes driven by CaMV d35S promoter were introduced in potato by Agrobacterium mediated genetic transformation. The expression and osmotin protein accumulation in transgenic potato were detected by Southern, Northern, and Dot-blot ELISA assay. Disease resistance test using P.infestens complex race showed that expression of both osmotin mutants in transgenic potato reduced the lesion growth rate in inoculated leaves. The results showed that accumulation of osmotin protein in intercellular spaces (delta C18osmotin) inhibited the development of fungal disease in inoculated leaves. Based on the results we suggest that antifungal activity was possibly located at N end of osmotin protein (osmotin-P).
Li
R
R
Biotechnology Research Center, Chinese Academy of Agricultural Sciences, Beijing, China.
Wu
N
N
Fan
Y
Y
Song
B
B
D015152:Blotting, Northern; D015139:Blotting, Southern; D004797:Enzyme-Linked Immunosorbent Assay; D016297:Mutagenesis, Site-Directed; D010838:Phytophthora / Q000254:growth & development*; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D010940:Plant Proteins / Q000378:metabolism*; D030821:Plants, Genetically Modified; D016133:Polymerase Chain Reaction; D011198:Solanum tuberosum / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology
D010940:Plant Proteins; C073139:osmotin protein, Nicotiana tabacum