The invention belongs to the field of 
plant biotechnology, in particular provides a polygalacturonase 
arrestin gene CaPGIP1 cloned from hot pepper, the 
gene can specially inhibit the activity of polygalacturonase (PGs) secreted by 
pathogenic bacteria. The invention provides the function 
verification techniques based on the coding of the 
gene, such as 
protein making, 
enzyme activity testing, 
gene silencing, transgenic excessive expression and the like and the application of the techniques. Based on the gene and 
protein operation technology, the CaPGIP1 gene is proved to effectively participate in the defense reaction of hot pepper under the induction of a stress facto, and can inhibit the activity of polygalacturonase (PGs) secreted by various 
pathogenic bacteria. The gene 
silence and 
transgenic technology are further used for proving that the 
silence or less expression of the gene in the hot pepper reduces the 
disease resistance of a host, and the excessive expression of the gene in the transgenic tobacco can enhance the resistance; therefore, the gene codes an important 
disease-resistance related 
protein. The invention provides an important technological reserve for transforming the polygalacturonase 
arrestin (PGIP) gene and cultivating a 
new disease-resistant variety.