Transgenic sweet potato expressing thionin from barley gives resistance to black rot disease caused by Ceratocystis fimbriata in leaves and storage roots.
Black rot of sweet potato caused by pathogenic fungus Ceratocystis fimbriata severely deteriorates both growth of plants and post-harvest storage. Antimicrobial peptides from various organisms have broad range activities of killing bacteria, mycobacteria, and fungi. Plant thionin peptide exhibited anti-fungal activity against C. fimbriata. A gene for barley α-hordothionin (αHT) was placed downstream of a strong constitutive promoter of E12Ω or the promoter of a sweet potato gene for β-amylase of storage roots, and introduced into sweet potato commercial cultivar Kokei No. 14. Transgenic E12Ω:αHT plants showed high-level expression of αHT mRNA in both leaves and storage roots. Transgenic β-Amy:αHT plants showed sucrose-inducible expression of αHT mRNA in leaves, in addition to expression in storage roots. Leaves of E12Ω:αHT plants exhibited reduced yellowing upon infection by C. fimbriata compared to leaves of non-transgenic Kokei No. 14, although the level of resistance was weaker than resistance cultivar Tamayutaka. Storage roots of both E12Ω:αHT and β-Amy:αHT plants exhibited reduced lesion areas around the site inoculated with C. fimbriata spores compared to Kokei No. 14, and some of the transgenic lines showed resistance level similar to Tamayutaka. Growth of plants and production of storage roots of these transgenic plants were not significantly different from non-transgenic plants. These results highlight the usefulness of transgenic sweet potato expressing antimicrobial peptide to reduce damages of sweet potato from the black rot disease and to reduce the use of agricultural chemicals.
Biotechnology Laboratory, Toyota Central R&D Laboratories, Inc., Nagakute, Aichi 480-1192, Japan. e1130@mosk.tytlabs.co.jp
Nobuhiko
N
Muramoto
Tomoko
T
Tanaka
Takashi
T
Shimamura
Norihiro
N
Mitsukawa
Etsuko
E
Hori
Katsunori
K
Koda
Motoyasu
M
Otani
Masana
M
Hirai
Kenzo
K
Nakamura
Takao
T
Imaeda
D000935:Antifungal Agents / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D001203:Ascomycota / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D060467:Disease Resistance / Q000187:drug effects / Q000235:genetics*; D015870:Gene Expression / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005822:Genetic Vectors / Q000235:genetics; D001467:Hordeum / Q000187:drug effects / Q000378:metabolism; D027723:Ipomoea batatas / Q000187:drug effects / Q000235:genetics* / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology*; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics / Q000382:microbiology*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000382:microbiology*; D030821:Plants, Genetically Modified; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D014170:Transformation, Genetic / Q000187:drug effects; D001614:beta-Amylase / Q000235:genetics
D000935:Antifungal Agents; D023181:Antimicrobial Cationic Peptides; D010940:Plant Proteins; C036092:hordothionin protein, Hordeum vulgare; C016085:purothionin; D001614:beta-Amylase