Heterogeneous Expression of an antifungal peptidein Escherichia coli and its activity assay

• Main Authors: LIANG TUNG JUNG, 梁棟榮
• Other Authors: Menghsiao Meng
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/69253311155136071055

碩士 === 國立中興大學 === 生物科技學研究所 === 93 === Yields of agricultural products are often reduced severely by fungal pathogens. Attempts to increase plant resistance to fungal pathogens through introduction of plant antifungal genes ( e.g. chitinase gene) into the plant have been reported repeatly. The outcome varies. One of the main limitations has been the relatively low level of resistance obtained with a single plant antifungal gene, which has resulted in the need to use gene combinations. Obviously, plant pathogens have already evolved tolerance to plant-derived antifungal compounds. In this experiment, we chose cicadin peptide whose antifungal activities have been reported. Cicadin is from dried juvenile cicadas which are used in traditional Chinese medicine for treatment of certain diseases. The synthetic cicadin gene was inserted into pTYB2 plasmid and introduced into Escherichia coli Novablue (DE3). After purification, the antifungal activity of the E. coli-expressed peptide was analyzed. Preliminary results show that the E. coli-expressed cicadin has some but not strong antifungal activity against Fusarium oxysporum f. sp. pisi; BCRC 35290. Yet, the antifungal activity of the recombinant cicadin needs to be confirmed through modifications of our assay method and tests of the other kinds of fungus in the future.