The invention relates to the field of 
genetic engineering, in particular to preparation of an infectious clone vector of a Pepper mild 
mottle virus (PMMoV) of 
RNA (ribonucleic acid) 
plant viruses and tobacco mosaic viruses, 
pathogenesis analysis on an infectiously cloned 
agrobacterium tumefaciens strain with the pepper mild 
mottle virus and exogenous proteins infectiously cloned and expressed by the aid of the PMMoV. The preparation, the 
pathogenesis analysis and exogenous proteins have the advantages that genomes of Shanghai bay isolate of the pepper mild 
mottle virus are constructed onto efficient 
plant expression vectors pCB301-CH by the aid of a 
genetic recombination process, the recombinant vectors are transferred into the 
agrobacterium tumefaciens strain by means of 
electroporation, and accordingly the virus vector with infection ability can be obtained; the 
plant expression vectors can be constructed by means of infectious 
cloning, and the exogenous proteins can be efficiently and stably expressed in 
host plants; mature systems can be provided for studying structures and functions of the virus genomes and studying interaction between the virus and hosts.