Abstract:
Plant defensins are small cysteine-rich globular proteins, and resist well against fungi, bacteria and weevils. Defensins bind to the active site of α-amylase in the weevil gut, thus inhibiting starch digestion in weevils. In this report, the authors present the results on the ability to
resist the weevils, cloning and determining the ZmDEF1 gene sequence of four local maize samples Maison, Laocai, Simacai, Luthan and a hybrid maize CP888. The CP888 performed lowest resistant ability to weevils, while Maison had highest one. The coding region of ZmDEF1 gene isolated from some maize samples had the size of 243 nucleotides, encoding 80 amino acids. The nucleotide sequences of ZmDEF1 gene of the samples have 5 positions that were different in nucleotide order. Deduced amino acid sequences of defensins of the local maize samples have 8 cysteines that made 4 disulfide bridges; hybrid maize CP888 had 7 cysteines. ZmDEF1 gene isolated from DNA had the size of 345 bp and consistsed of two exons and one in tron. The mRNA sequences of ZmDEF1 gene could be used to create a transformation vector for gene transfer to improve the ability to resist weevils in maize.
Keywords:
Cys, defensin, maize weevil, resistant to
weevils, Zea mays, ZmDEF1.