It has been demonstrated that the
lectin from Musa paradisiaca (BanLec-1) could inhibit the cellular entry of human immunodeficiency virus (HIV). In order to evaluate its effects on tobacco mosaic virus (TMV), the banlec-1 gene was cloned and transformed into Escherichia coli and tobacco, respectively. Recombinant BanLec-1 showed
metal ions dependence, and higher thermal and pH stability. Overexpression of banlec-1 in tobacco resulted in decreased leaf size, and higher resistance to TMV
infection, which includes reduced TMV cellular entry, more stable
chlorophyll contents, and enhanced
antioxidant enzymes. BanLec-1 was found to bind directly to the TMV
capsid protein in vitro, and to inhibit TMV
infection in a dose-dependent manner. In contrast to limited prevention in vivo, purified rBanLec-1 exhibited more significant effects on TMV
infection in vitro. Taken together, our study indicated that BanLec-1 could prevent TMV
infection in tobacco, probably through the interaction between BanLec-1 and TMV
capsid protein.