Functional Identification Of StPTF1 Gene In Potato

The plant transcription factor bHLH?basic Helix-Loop-Helix?plays an important role in some biological process,regulating growth and development as well as responding to environmental stress.Phosphate transcription factor 1?PTF1?belongs to the bHLH family,effectively regulating plants to achieve the adaptive growth under phosphate stress.At present,the function of PTF1 gene in rice?Oryza sativa?,soybean?Glycine max?and corn?Zea mays?has been reported,however,the potato?Solanum tuberosum L.?StPTF1gene is rarely studied.In this study,the complete mRNA nucleotide sequence of potato StPTF1 gene was obtained through the basic local alignment search tool?Basic local alignment search tool,BLAST?,and its structure and function were analyzed and identified,respectively.The results are as follows:1.The complete mRNA sequence of potato StPTF1 gene was obtained via homologous alignment.The GenBank database accession is XM₀06351155.2,and the sequence length of open reading frame?ORF?is 1083 bp,encoding 360 amino acid residues.Moreover,molecular weight and isoelectric point of StPTF1 protein are 39.68 KDa and 5.92,respectively.Evolutionary relationship analysis through Clustal X and MEGA6.0 found that StPTF1 gene was more conservative.In addition,the analysis of protein properties suggested that StPTF1 is a hydrophilic protein,and it lack of transmembrane structure.2.The homologous recombination method was used to construct the transient expression vector pEGFP-StPTF1 of StPTF1 gene marked by green fluorescent protein?GFP?.Then,tobacco leaf infection experiments found that the potato StPTF1 gene was expressed in the nucleus.The analysis from expression pattern of StPTF1 gene in roots,stems and leaves under phosphate stress from different time points?0,3,6,9,12,24,72 and 120 h?through Quantitative real-time PCR?qRT-PCR?suggested that StPTF1 was expressed in all tissues and the stress time could affect its the expression abundance,and the expression level in roots was significantly higher than stems and leaves.In addition,the expression of StPTF1 gene in roots,stems and leaves was significantly increasing.In contrast,the expression in the roots was the most obvious,but there was no difference in stems and leaves in 6,12 and 72 h period times.3.The overexpression vector pBI121-StPTF1 and the interference expression vector pCPB121-StPTF1 were used to transform microtubers of potato variety ‘Desireé',respectively,obtaining four overexpression and three interference expression transgenicplants identified by Kanamycin resistance rooting screening and PCR detection of neomycin phosphotransferase?NPT??gene in transgenic plants.4.The qRT-PCR method was used to analyze the StPTF1 gene expression level of seven transgenic plants treated under low phosphorus stress at 0,1 and 15 d.The results revealed that the expression levels of StPTF1 gene were increasing of four overexpressed transgenic plants with the extension of stress time,and there are differences in expression between each transgenic plant.In addition,there was no significantly difference in the expression level of StPTF1 gene among the three interfering expression plants.