Cloning And Expression Analysis Of DREB Transcription Factor Genes From Paulownia Fortunei

Paulownia fortunei belongs to the fast-growing tree species,is endemic to China.It has a very high economic and ecological value.Improved varieties of Paulownia fortunei by genetic engineering technology can compensate for the deficiency of conventional breeding methods and accelerate the development of Paulownia fortunei in genetic breeding direction.During the growth of Paulownia fortunei,drought,salt damage,extreme temperatures and other environmental stress factors can seriously affect the physiological activity and growth..Plants can regulate and control their physiological metabolism and growth at the transcriptional level from regulating the expression of related genes by transcription factor.DREB transcription factors exist widely in the plants.Participating in regulating the expression of various functional genes,to improve the stress resistance of plants.In this study,one stress-related gene had been cloned from Paulownia fortunei which named Pf DREB2.It was found that the gene had the basic characteristics of DREB gene under the bioinformatics analysis.The main results of this study were as follows:1.The experimental material was the leaves of Paulownia fortunei.A pair of degenerate primers was designed according to the conserved regions which encoding the DREB DNA binding domains in plant DREB genes.One fragments was amplified by PCR.The new gene encoding DREB transcription factors,Pf DREB2 was isolated by RACE-PCR.Comparison of deduced amino acid sequences showed that it was a typical DREB transcription factors.2.The full-length DNA sequence of Pf DREB2 was amplified using genomic DNA and c DNA as templates.The results indicated that the gene had no intron.3.The full-length c DNA sequence of Pf DREB2 was 1049 bp,648bp ORF frame,encoded 215 amino acids.The protein encoded by the gene might contain a typical AP2 / EREBP domain,the domain consisted of 64 amino acids.The article 14 of this domain was valine and the article 19 of this domain was leucine.The amino acid sequence contained a serine-rich region and glutamine-rich region,C-terminal contained a acidic activation domain.The protein might be localized in the nucleus.The BLAST alignment in the NCBI showed that Pf DREB2 had the highest identity to Sesamum indicum DREB2 B.4.The analysis about gene expression changes of Paulownia fortunei Pf DREB2 under drought,high salt,low temperature,ABA-induced by real-time quantitative PCR showed that the gene was hardly expressed without any stress treatment conditions,the Pf DREB2 gene expression was the highest under the drought induced,the degree of expression changes was greatest than it was under high salt and low temperature induced,so it was more sensitive to drought stress.It showed that when Paulownia fortunei suffered the adversity stress,the gene had a regulatory role.Paulownia fortunei Pf DREB2 was hardly expressed under ABA treatment which indicated that the genewas not affected by exogenous ABA regulation.