火龙果HpTCP9基因克隆及其在干旱胁迫下的表达分析OA北大核心CSTPCD

TCP(teosinte branched1/cycloidea/proliferating cell factor)is a plant specific transcription factor that is widely involved in plant growth and development and response to environmental stress.TCP9 is a classⅠ member of TCP gene family and plays an important role in respose to plant drought stress.Pitaya(Hylocereus sp.)is an ideal material for drought resistance research because of the strong drought resistance.Hylocereus polyrhizus variety'Da Hong'were used to isolated the HpTCP9 gene by RT-PCR technology in order to investigate the biological function of the TCP9 gene in the drought resistance of pitaya.Bioinformatics analysis showed that the ORF length of the HpTCP9 gene was 729 bp,encoding 242 amino acids,with a molecular weight of 24.86 kD,an isoelectric point of 5.04,and a hydrophilicity index of 1.021.Domain analysis showed that the HpTCP9 protein sequence had a typical TCP conserved domain.The protein structure prediction results indicated that α spiral was 12.40%,irregular curls were 66.12%,and extended chains were 12.81%,The β-turn was 8.68%.To detect the subcellular localization of HpTCP9,a pCAMBIA2300-HpTCP9-GFP expression vector carrying a GFP tag was constructed.HpTCP9 was detected as a nuclear localization protein through Arabidopsis protoplast transformation.Real time fluorescence quantitative PCR analysis showed that the HpTCP9 gene was significantly upregulated by 20%PEG6000 simulated drought treatment,and the expression level was positively correlated with the treatment duration.The above results indicated that the HpTCP9 belonged to the ClassⅠsubfamily of the TCP family,had a TCP conserved domain,was a hydrophobic protein located in the nucleus,and played a role in the drought stress defense mechanism of H.polyrhizus.This study provides a theoretical basis for further exploring the function of the HpTCP9gene in H.polyrhizus.