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This study reports the characterization of protein elicitor PeBb1 derived from entomopathogenic fungus <i>Beauveria bassiana</i> ARSEF-2860 strain and its putative role in induced systemic resistance in <i>Brassica rapa</i> ssp. <i>pekinensis</i> against green peach aphid <i>Myzus persicae</i>. The sequence of purified elicitor protein was matched with the genomic sequence of a hypothetical protein BBA_10269 from <i>B. bassiana</i> ARSEF-2860 (GenBank Accession No. XP_008603588.1). The protein-encoding gene <i>PeBb1</i> contained 534 bp cDNA encoding a polypeptide of 177 amino acids with a molecular mass of 19 kDa. The recombinant elicitor protein was expressed in <i>Escherichia coli</i> using pET-28a (+) expression vector and induced necrosis in the leaves of tobacco. The effects of elicitor protein on aphid <i>M. persicae</i> was determined by applying three different concentrations of PeBb1 (i.e., 26, 35, 53 &#956;M) on <i>B. rapa</i> plants at 4-leaf stage and the treated plants were exposed to newly emerged (0&#8722;6 h old) apterous adult aphids. Bioassay results showed significant (<i>p</i> &lt; 0.05) sub-lethal effects of the exogenous application of PeBb1 elicitor on <i>M. persicae</i>. Moreover, the RT-qPCR gene expression analyses showed a significant up-regulation of most of the key genes linked to ethylene (ET)- and jasmonic acid (JA)-associated plant defense pathways in elicitor-treated plants. These results not only recommend the putative utilization of PeBb1 elicitor protein in future biological pest control strategies against phloem-feeding insect pests such as <i>M. persicae</i>, but also help in better comprehension of the mechanisms through which beneficial fungi trigger the induced plant resistance.