Cloning and functional analysis of inducible promoter Rd29A in transgenic tobacco plants

Stress inducible promoters are key elements in development of transgenic abiotic resistant plants. Abiotic stress inducible promoter Rd29A was cloned by Polymerase chain reaction (PCR) from Arabidopsis thaliana genomic DNA. pBI-RD-GUS binary vector constructed by replacing CaMV35S promoter of vector pBI121 by Rd29A. The new recombinant vector pBI-RD-GUS as well as pBI121 was transferred to tobacco by Agrobacterium tumefaciencs system. PCR and GUS histochemical assay of transgenic tobacco plants confirmed transformation events. Stress induciblity of the promoters studied by histochemical GUS assay of transgenic leaves under stress conditions. The assay showed that promoter Rd29A، in contrast of CaMV35S، induced by dehydration، NaCl and ABA. Rd29A induction by ABA confirmed the signaling role of it in stress signal transduction pathways. Therefore، if abiotic stress resistance genes are driven by rd29A in the transformed plant، the disadvantage، like small figure، low growth rate etc، to transgenic plant due to the over-expression of exogenous genes can be greatly reduced.