Abstract: P2 gene of Wheat yellow mosaic virus(WYMV) was amplified by RTPCR from WYMV infected wheat leaves. Sequence analysis indicated that P2 gene constituted of 2 635 nts， encoding a protein of 875 aminoacids (AA) with estimated molecular weight of 72 kDa. Due to its large protein molecular weight， it is difficult to be expressed in prokaryotic expression system. Thus， 5′terminal and 3′terminal parts of P2 gene (1 kb each) were subcloned into the prokaryotic expression vector pMALC2X， respectively. Subsequently， the expressed MBPP2N and MBPP2C fusion protein were induced by IPTG in E.coli BL21 (DE3). The abundantly induced MBPP2C infusion protein then was purified， and the rabbit antiserum against to this protein was prepared. Experiments indicated that this antiserum can be used to detect the P2 protein in WYMV infected wheat leaves by Western blotting and immunogold labeling. It was shown that WYMV P2 protein was located in subcellular membranous body， indicating that this protein might be associated with membranederived inclusions．

Key words: Wheat yellow mosaic virus, P2 gene, prokaryotic expression, antiserum preparation, immunogold localization