들잔디로부터 β-1,3-glucanase 유전자의 클로닝 및 특성분석

Molecular cloning and characterization of β-1,3-glucanase gene from Zoysia japonica steud

Rhizoctonia leaf blight (large patch) has become a serious problem in Korean lawn grass, which is extremely hard to treat and develops mostly from the roots of lawn grass to wither it away. Rhizoctonia leaf blight (large patch) is caused by Rhizoctonia solani AG2-2 (IV). To develop zoysia japonica with strong disease tolerance against this pathogenic bacterium, β-1,3-glucanase was cloned from zoysia japonica, which is one of the PR-Proteins known to play a critical role in plant defense reaction. β-1,3-glucanase is known to be generated within the cells when plant tissues have a hypersensitive reaction due to virus or bacterium infection and secreted outside the cells to play mainly the function of resistance against pathogenic bacteria in the space between the cells. This study utilized the commonly preserved part in the sequence of corn, wheat, barley, and rice which had been researched for their disease tolerance among the β-1,3-glucanase monocotyledonous plants. Based on the part, degenerate PCR was performed to find out the sequence and full-length cDNA was cloned. E.coli overexpression was conducted in this study to mass purify target protein and implement in vitro activation measurement and antibacterial test. In addition, to interpret the functions of ZjGlu1 gene, each gene-incorporating plant transformation vectors were produced to make lawn grass transformant. Based on ZjGlu1 protein, antibacterial activity test was conducted on 9 strains. As a result, R. cerealis, F. culmorum, R.solani AG-1 (1B), and T. atroviride were found to have antibacterial activity. The gene-specific expression amount in each organ showed no huge difference in the organs based upon the transformant and against 18s gene expression amount.