PROBLEM TO BE SOLVED: To provide a method for protecting plants from being infected with pathogenic bacteria and/or virus. SOLUTION: The method for protecting plants from being infected with pathogenic bacteria and/or virus comprises overexpressing a vacuole processing enzyme. Use of the vacuole processing enzyme or a nucleic acid encoding the enzyme therefor is provided. A method for screening agent candidates for protecting plants from being infected with pathogenic bacteria and/or virus is provided, comprising the steps of contacting cells holding the nucleic acid with a test sample and of evaluating the expression or activity of the vacuole processing enzyme. An alternative method for screening agent candidates for protecting plants from being infected with pathogenic bacteria and/or virus is provided, comprising assaying the physiological activity of the enzyme in the presence of a test sample. A polypeptide comprising a specific amino acid sequence and having the physiological activity of the enzyme, and a nucleic acid encoding the polypeptide are provided, respectively. COPYRIGHT: (C)2005,JPO&NCIPI
