Main Article Content
Plants are exploited as a source of food by a wide range of parasites, including viruses, bacteria, fungi, nematodes, insects and even other plants. So paying attention to their protection is very important. One of the most important groups of defensive gene is pathogenesis-related (PR) proteins. PR proteins are a group of plant proteins which accumulate as a result of different types of pathogens attack. Thaumatinlike proteins (TLPs) belonging to the PR proteins, plays an important role in plant defense against pathogen invasions. Agrobacterium-mediated transformation is routinely used for the transformation of many plants. In the present study, thaumatin-like TLP-3 gene without signal peptide was transferred into tobacco plants through Agrobacterium-mediated technology. The PCR and RT-PCR assays confirmed the presence of TLP-3 gene and TLP-3 mRNA in transgenic tobacco plants, respectively. The bioassay results showed the activity of TLP-3 against Alternaria alternata in microscopic experiment. This is the first report of the expression of TLP-3 gene without signal peptide in tobacco plants using Agrobacterium mediated transformation and it confirmed the ability of the gene action in another plant.
Key words: Thaumatin like protein, Agrobacterium, signal peptide, Alternaria alternate.