Isolation and Characterization of Protease Inhibitor Gene by Construction of Genomic Library of Black Gram (Vigna mungo L.)

Plant protease inhibitors (PIs) are small proteins abundant in storage organs such as seeds and tubers. They have been implicated in binding to proteases of insects and interfere with the digestive process, there by proving their insecticidal activity. Black gram is known to be a source of plant protease inhibitors. A genomic DNA library of Black gram variety Uttara was constructed in Fosmid vector. Primary and secondary screening of library using mung bean protease inhibitor gene as a probe resulted in isolation of recombinant clones containing protease inhibitor gene and promoter. The positive clones were further confirmed by PCR and subsequently sequenced. The nucleotide sequence of genomic clone was analyzed by Blastn algorithm of NCBI database and 5’ upstream sequence was analysed in-silico by Place and Plant Care databases.