Abstract:

This work aims to obtain PcMYB1 promoter from Polygonum cuspidatum and analyze its activity,and thus to lay a basis for further investigating the functions of promoter PcMYB1 promoter. hiTAIL-PCR was used to clone the PcMYB1 promoter from the leave genome DNA of P. cuspidatum,and bioinformatics analysis of it was conducted. The full-length promoter P1（+1 to -2 884）and a series of progressive 5' truncated promoters P2（+1 to -2 259）,P3（+1 to -1 807）and P4（+1 to -1 362）were fused with GUS gene,and the recombinant expression vector P1∷GUS,P2∷GUS,P3∷GUS,P4∷GUS were constructed,respectively. Each recombinant expression vector was transferred into Agrobacterium rhizogenes to transform the hairy root of P. cuspidatum,and the transformed positive hairy root was used as the material. GUS histochemical staining was performed to analyze the activity of the promoter. The 2 884 bp promoter sequence（GenBank accession number：MT811057）of the promoter was obtained. The promoter contained several core fragments（TATA-box and CAAT-box）essential for eukaryotic promoters,and also cis-elements that were responsive to MeJA and low-temperature and cis-acting regulatory elements that were associated with light and anaerobic responses. The successful constructions of the recombinant vectors were confirmed via PCR. The transgenic hairy roots of P. cuspidatum can be stained to have blue,but the color was light compared to the control,that demonstrated that both the full-length promoter and the other 5' truncated promoters drove the GUS gene expression,but the driving ability was lower than that of CaMV35S promoter. In sum,PcMYB1 promoter is successfully cloned and it shows the activity of driving the expression of downstream GUS.

Key words: Polygonum cuspidatum Sieb. et Zucc., PcMYB1, promoter, sequence analysis, GUS activity