Characterization of Mi_(1.2) Whitefly (Bemisia tabaci) Resistance Gene

摘要

Tomato (Solanum peruvianum) Mi gene provides resistance to whitefiy (Bemisia (abaci), potato aphids and nematode making Mi a useful source in integrated pest management program. The aim of this work was to isolate, clone and sequence Miu gene from S.peruvianum. In addition, physico-chemical identification of amino acids deduced from Miu gene was done. Secondary (2D) and tertiary (3D) structures of Mi12 protein were also predicated. Distinct amplicons of 620, 600, 3300 and 1993 bp were successfully amplified using PCR amplification. The full-length DNA (5.4 kbp) and cDNA (4 kbp) of MiL2 gene was isolated using specific primers. Fragments 620 and 600 bp cloned into Escherichia coli XL~(-1) Blue and sequenced. Sequencing results of both assembled fragments (620 and 600 bp) joined at the overlap region (1440 bp). A BLAST search confirmed that the DNA sequence from the amplified fragments was Mi12 gene. It shared 98% identity and deduced amino acids shared 97% identity with Miu gene published in GenBank. An Open reading frame (ORF) of Mi|;2 protein encoded for 479 amino acid residues with molecular weight 54.59 KDa and isoelectric point (PI) 5.52 was calculated using Expasy's ProtParam server. 2D and 3D structures of Mi].2 protein was analyzed using SOPMA and Swiss-Prot software, respectively.