Molecular Cloning And ExpressionAnalysis Of CBF In Astragalus Tembranaceus

Radix Astragali is a popular traditional Chinese medicine,and Astragalus membranaceus and A.membranaceus var.mongolicus are two commonly used species,and has a wide range of potential therapeutic applications and clinical efficacy.Astragalus membranaceus(Fisch.)Bunge.grows in the cold northern regions of China,and low temperatures is beneficial to the accumulation of active ingredients in it.The CBF gene is a cold-response gene and plays a significant role in plant response to low temperature and regulatory pathways.In this study,the CBF gene(AmCBF)was cloned from Astragalus membranaceus(Fisch.)Bunge.Based on the biological information of the promoter,the transcription and expression analysis of adventitious roots of A.membranaceus was camed out.To explore the molecular mechanism of the accumulation of active ingredients in A.membranaceus has laid the foundation.The results of the study are as follows:The full-length AmCBF gene sequence is 879 bp,including an open reading frame of 642,and on-line analysis software predicts that it encodes 213 amino acids with a theoretical isoelectric point of 5.84.It is predicted to be located in the cytoplasm and the encoded protein is a hydrophilic protein;The promoter of CBF gene was obtained by chromosome walking method.The full-length sequence was 483 bp.Bioinformatics analysis showed that there was 1 BOX II(light-responsive element),2 G-boxes(light-acting regulatory elements),1 MBS(MYB binding site,involved in drought-induced response),2 LTREOOREATOOR15(low-temperature-response element)and one TCA-box(salicylic acid response cis-acting element)cis-acting element.qRT-PCR showed that:The transcription of AmCBF in roots,stems and leaves was negatively correlated with the increase of temperature,and the expression was highest in April and October.Treatments with low temperature,drought,light,gibberellin,methyl jasmonate,and salicylic acid upregulated the expression of AmCBF,and the expression of AmCBF was up-regulated most obviously at low temperature,which was 14.2 times that of the control group.