Overexpression of a defensin enhances resistance to a fruit-specific anthracnose fungus in pepper.
Functional characterization of a defensin, J1-1, was conducted to evaluate its biotechnological potentiality in transgenic pepper plants against the causal agent of anthracnose disease, Colletotrichum gloeosporioides. To determine antifungal activity, J1-1 recombinant protein was generated and tested for the activity against C. gloeosporioides, resulting in 50% inhibition of fungal growth at a protein concentration of 0.1 mg·mL-1. To develop transgenic pepper plants resistant to anthracnose disease, J1-1 cDNA under the control of 35S promoter was introduced into pepper via Agrobacterium-mediated genetic transformation method. Southern and Northern blot analyses confirmed that a single copy of the transgene in selected transgenic plants was normally expressed and also stably transmitted to subsequent generations. The insertion of T-DNA was further analyzed in three independent homozygous lines using inverse PCR, and confirmed the integration of transgene in non-coding region of genomic DNA. Immunoblot results showed that the level of J1-1 proteins, which was not normally accumulated in unripe fruits, accumulated high in transgenic plants but appeared to differ among transgenic lines. Moreover, the expression of jasmonic acid-biosynthetic genes and pathogenesis-related genes were up-regulated in the transgenic lines, which is co-related with the resistance of J1-1 transgenic plants to anthracnose disease. Consequently, the constitutive expression of J1-1 in transgenic pepper plants provided strong resistance to the anthracnose fungus that was associated with highly reduced lesion formation and fungal colonization. These results implied the significance of the antifungal protein, J1-1, as a useful agronomic trait to control fungal disease.
Medicinal Nanomaterial Institute, BIO-FD&C Co. Ltd., Incheon, Korea.
Hyo-Hyoun
HH
Seo
Department of Biotechnology, Chonnam National University, Gwangju, Korea.
Sangkyu
S
Park
Experiment Research Institute, National Agricultural Products Quality Management Service, Seoul, Korea.
Soomin
S
Park
Biological Control Center, Jeonnam Bioindustry Foundation, JeollaNamdo, Korea.
Byung-Jun
BJ
Oh
Department of Biotechnology, Chonnam National University, Gwangju, Korea.
Kyoungwhan
K
Back
Department of Biotechnology, Chonnam National University, Gwangju, Korea.
Oksoo
O
Han
Department of Biotechnology, Chonnam National University, Gwangju, Korea; Kumho Life Science Laboratory, Chonnam National University, Gwangju, Korea.
Jeong-Il
JI
Kim
Department of Biotechnology, Chonnam National University, Gwangju, Korea; Kumho Life Science Laboratory, Chonnam National University, Gwangju, Korea.
Young Soon
YS
Kim
D002212:Capsicum / Q000235:genetics* / Q000276:immunology / Q000378:metabolism / Q000382:microbiology*; D020231:Colletotrichum / Q000187:drug effects / Q000502:physiology*; D003517:Cyclopentanes / Q000378:metabolism; D023082:Defensins / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D060467:Disease Resistance / Q000235:genetics*; D005638:Fruit / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology*; D015870:Gene Expression; D009928:Organ Specificity; D054883:Oxylipins / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology*; D030821:Plants, Genetically Modified; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology
D003517:Cyclopentanes; D023082:Defensins; D054883:Oxylipins; D012333:RNA, Messenger; D011994:Recombinant Proteins; C011006:jasmonic acid