Cloning And Function-selection Analysis Of Several Transcription Factors Genes

Plants are exposed to various environmental stresses,such as drought,salt,cold and pathogens.To survive under these different biotic and abiotic stresses,plants have developed an elaborate signaling network that perceives these signals and modulates the expression of specific resistance genes.In these pathways,transcription factors play important roles in controlling the expression of specific str:ess-related genes.Saline and drought are the most important abiotic factors affecting crop production in the world.Over the last decades,much efforts have been made on breeding of crops tolerant to salt and drought by transferring foreign salt/drought-tolerant functional and transcriptional genes into crop cultivars.In this paper,4 MYC gene sequences were in silieo cloned from cotton(Gossypium hirsutum)genome data,and then cloned form cotton cultivars using RT-PCR method.The 4 GhMYC genes,along with 3 ERF and 4 DREB genes,were transferred into Arabidopsis thaliana.The transgenic A.thaliana plantswith different genes integrated were charged to salt and drought stress,and their tolerance to salt and drought stress were compared.Major results are as follows:(1)Results of bioinformatics analysis to the GhMYC 1-4 gene sequences and their encoded proteins showed that all the proteins encoded by the genes have typical structural characters of bHLH-MYC.(2)Effective plant expression vectors harboring GhMYC1-4 were constructed with the Gateway technology.Six plant expression vector harboring 3 different DREB and 3 ERF genes respectively,were also constructed meanwhile.All the 10 genes were then transferred to A.thaliana.Transgenic plants thus obtained were charged to salt and drought conditions.The result demonstrate that transgenic A.thalianaplants with GhMYC1,GhMYC4,KcERF and PeDREB2a genes integrated showed higher tolerance to salt and drought as compared to the other 3 genes..(3)A microorganism-original herbicide resistant gene GR79 was modified the codons using codon usages preferred by plants,and synthesized chemically.The gene thus obtained was used as the selective marker gene for A.thaliana transformation.Results of the selective pressure experiments showed that a 0.15%solution of glyphosate could be used for screening of the transgenic A.thaliana.