苹果NIGT1/HRS1/HHO转录因子MdHHO3基因的克隆及功能分析OA

Taking apple dwarfing rootstock'M26'as the test material,the apple NIGT1/HRS1/CHO transcription factor MdHHO3 gene was amplified by PCR and subjected to comprehensive bioinformatics analysis.The expression pattern of MdHHO3 gene was analyzed by qRT-PCR,and the effect of this gene on the absorption and utilization of nitrogen and phosphorus nutrients in apples was studied by gene overexpression method,in order to provide reference for further revealing the mechanism of MdHHO3 in coordinating nitrogen and phosphorus balance in apples.The results showed that the cDNAfull length of MdHHO3 was 1 115 bp and encodes 371 amino acids.The molecular weight.the theoretical isoelectric point and the average hydrophilicity index of the protein were 90 548.77,5.04 and 0.862 respectively.MdHHO3 was a hydrophobic protein and was located in the cell nucleus.Expression pattern analysis showed that nitrogen deficiency inhibited the expression of MdHHO3,while phosphorus deficiency induced its upregulation.Moreover,under short-term phosphorus deficiency treatment,the expression level of MdHHO3 in roots reached the peak at 3 hours and 24 hours respectively.The results of functional identification indicated that under nitrogen deficiency treatment,the total nitrogen content in the MdHHO3 overexpressed apple callus decreased,and its growth was significantly inhibited.Under phosphorus deficient condition,overexpression of MdHHO3 promoted the absorption and accumulation of total phosphorus in apple callus,maintained the normal growth of transgenic callus.In conclusion,MdHHO3 played an important regulatory role in the absorption and utilization of nitrogen and phosphorus in apple.