• Animal cells and systems
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• 제7권4호
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• pp.337-343
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• 2003

Methyl jasmonate (MeJA) is a signal molecule in the activation of defense responses in plants. In this study, we isolated 15 MeJA-inducible genes by subtractive hybridization. These genes encode two myrosinase-binding proteins, five lipase-like proteins, a polygalacturonase inhibitor, a putative chlorophyll-associated protein, a terpene synthase, a dehydroascorbate reductase, an ascorbate oxidase, a cysteine protease, an O-methyltransferase, and an epithiospecifier protein. Northern analysis showed that most of the Chinese cabbage genes are barely expressed in healthy leaves, but are strongly induced by MeJA treatment. We also examined whether these MeJA-inducible genes were activated by ethethon, BTH, and Pseudomonas syringae pv. tomato (Pst), a nonhost pathogen of Chinese cabbage. The results showed that none of the MeJA-inducible genes was strongly induced by ethephon or by BTH. The genes encoding lipase-like proteins and a myrosinase-binding protein were weakly induced by Pst. Other MeJA-inducible genes were not activated at all by the pathogen.

• Animal cells and systems
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• 제9권4호
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• pp.239-244
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• 2005

A cDNA clone for a wound- and pathogen-induced gene in Chinese cabbage (Brassica rapa subsp. pekinensis) was isolated and characterized. The cabbage gene, designated BrPR4, encodes a pathogenesis-related protein 4 (PR4) of 140 amino acids. The BrPR4 protein shows high similarity with wound-inducible antifungal proteins of tobacco, potato, barley, and wheat. The BrPR4 gene is locally induced by a nonhost pathogen, Pseudomonas syringae pv. tomato, that elicits a hypersensitive response in Chinese cabbage. Treatment of the cabbage leaves with benzothiadiazole (BTH), methyl jasmonate or ethephon showed that the BrPR4 gene expression is strongly induced by ethylene, but not by methyl jasmonate or BTH. The BrPR4 gene is also activated by wounding. Interestingly, however, the wound-inducible BrPR4 gene expression is repressed by salicylic acid or BTH, suggesting that there is cross-talk between salicylate-dependent and -independent signaling pathways.

• Journal of Photoscience
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• 제7권2호
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• pp.53-58
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• 2000

We performed the cloning of a chalcone synthase (CHS) gene, the key enzyme in the anthocyanin biosynthesis, from the cDNA library constructed with grape suspension cells irradiated UV-B. The PCR fragment was used to cloning the CHS gene. One CHS cDNA clone containing an open reading frame and a partial stilbene synthase (STS)cDNA, the stilbene-type phytoalexin, were isolated. The CHS cDNA clone (VCHS) showed 87% sequence homology with VvCHS (V.vinifea) and 72.3% identity with VSTSY(V.vinifea). its amino acid sequences were longer than any other CHS genes as 454 residues. Two genes were weakly expressed in white light irradiated cells, but highly induced in UV-B irradiated condition during 32 hours. Interestingly, the STS was quickly and abundantly expressed from 2 hours when supplemented with jasmonic acid (JA) and the maximum expression was observed at 4 hours and then gradually decreased. But, the additional UV-B or white light quickly degraded the STS expression than only JA treated grape suspension cells. The CHS also was rapidly induced with JA and the synergistical effect was observed at the addigional light treatment of UV-B or white light. These results are indicated that CHS and STS have different response mechanisms against the environmental stresses.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.79.2-80
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• 2003

To better understand plant defense responses against pathogen attack, we identified the transcription factor-encoding genes in the hot pepper Capsicum annuum that show altered expression patterns during the hypersensitive response raised by challenge with bacterial pathogens. One of these genes, Ca1244, was characterized further. This gene encodes a plant-specific Type IIIA - zinc finger protein that contains two Cys$_2$His$_2$zinc fingers. Ca1244 expression is rapidly and specifically induced when pepper plants are challenged with bacterial pathogens to which they are resistant. In contrast, challenge with a pathogen to which the plants are susceptible only generates weak Ca1244 expression. Ca1244 expression is also strongly induced in pepper leaves by the exogenous application of ethephon, an ethylene releasing compound. Whereas, salicylic acid and methyl jasmonate had moderate effects. Pepper protoplasts expressing a Ca1244-smGFP fusion protein showed Ca1244 localizes in the nucleus. Transgenic tobacco plants overexpressing Ca1244 driven by the CaMV 355 promoter show increased resistance to challenge with a tobacco-specific bacterial pathogen. These plants also showed constitutive upregulation of the expression of multiple defense-related genes. These observations provide the first evidence that an Type IIIA - zinc finger protein, Ca1244, plays a crucial role in the activation of the pathogen defense response in plants.