transfer of expb2 gene to nicotina tabacum for enhance drought tolerance

cell expansion and cell division are two main processes in plant growth and development. expansin proteins play a role key in cell expansion. these non-enzyme proteins involve in many growth and developmental processes. this protein affects drought tolerance. atexpb2 gene belongs to these proteins family. atexpb2 gene mainly expresses in the root tissue. in this study the expb2 gene, that was isolated from arabidopsis taliana dna genomics, transferred to nicotina tabacum plant. gene transfer was performed by agrobacterium-mediated technique. explants were inoculated by agrobacterium and then were planted on m.s medium contained antibiotic of kanamycin. finally, the tolerant seedlings were transferred to pots. polymerase chain reaction was used to confirm the transgenic plants. good rooting of transgenic plants suggests that this gene was increased root length and density.the results suggest that the expression of these genes in the aerial parts of the plant can cause undesirable traits such as loss of flower buds and leaf loss.