Transformation Genetic Tobacco with BtCspB Coding Cold Shock Protein Agrobacterium Tumefaciens-Mediated

Abstract

Cold shock protein (Csp) is essential for organisms to survive in the abiotic stress condition. It protects RNA from misfolding caused by various abiotic stresses. BtCsp gene had been isolated from Bacillus thuringiensis, fused to promoter of ubiquitin in the T-DNA of pCambia 1300int, and introduced into Agrobacterium tumefaciens LBA4404. We suppose that plant overexpressing this gene would be tolerant to abiotic stress including cold heat and drought stress. This research had an objective to transform genetically Nicotiana tabacum cv Samsun by BtCsp gene under the control of pUbiquitin promoter and NosT terminator mediated by A. tumefaciens. Leaf disks were inoculated by the method of co-cultivation with A. tumefaciens LBA4404 harboring pCambia1300int-BtCspB. We compared the effect of shoaking time between 20 and 30 minutes on the transformation efficiency. The transformation calli were selected on the medium containing 20 mg/l and 50 mg/l hygromcin and regenerated on MS medium containing 1 mg/l BAP and 0,1 mg/L IAA. Based on resistant calli to 50 mg/l hygromicin, the efficiency of transformation between 20 and 30 minutes was selatively equal i.e 65% and 57.5% respectively. PCR analaysis showed that BtCspB gene under the control of Ubquitin promoter is integrated into N. tabacum genome of To generation. Genetic analysis showed that hpt gene was inherited to the progeny T1 generation following Mendalian law. Based on chi-square analysis, the ratio of resistant and sensitive plant To hygromycin in T1 generation was 3:1, indicating that only one copy of hpt gene was integrated into the genome of transgenic plant in To generation.