Functional Analysis Of The Maize Transcription Factor ZmPTF1 Gene

bHLH transcription factors are widely present in various tissues of higher plants and attend the regulation of numerous metabolic processes. ZmPTF1 is a member of bHLH transcription factor family. According to research, ZmPTF1 regulates carbon metabolism and root growth to enhance resistance to low phosphorus of corn, it is also effective to fight with low nitrogen, drought and high salt. At the same time overexpressed ZmPTFl causes the change of gene expression. These differentially expressed genes are related to various matabolic pathways, such as pathways of disease resistance, secondary metabolism, hormone metabolism, signal transduction and carbohydrate metabolism induced by PAMPs.In this experiment, chose the ZmPTF1 gene cloned from corn A318 by predecessors as subject, to analyze the cis-actiong elements of its promoter, and build the plant expression vector PCAMBIA3301-ZmPTF1. Then imported it to tobacco through agrobacterium-me-dia to do research on biological functions of the gene. Besides preliminarily screenon the target genes of ZmPTF1 protein. The main research results are as follows:1.Used biological information tools to analyze the cis-actiong elements of ZmPTFl’s promoter and physical and chemical properties of its predicted protein. The result showed that there were various hormone response elements, number of soercive response element of biotic and abiotic, and some elements related to basal metabolism in the area. The protein is one kind of hydrophobic proteins formed by 481 kinds of amino acid residues.2.Transferred the constructed prokaryotic expression vector PET-32a-ZmPTFl into prokaryotic expression strain BL21, and induced the expression by IPTG. In this step we got ZmPTF1/His fusion protein of about 52.5KDa.3.Used maize total DNA as target, and ZmPTF1/His fusion protein expressed by prokaryotic the bait to choose target gene fragments which can be combined by pull-down method, and got 15 sequences.Then analysesed alignment on the sequencing result and chose 10 possible target gene fragments of ZmPTF1. The candidates were mainly related to signal transduction of hormone synthesis, biotical and abiotical stress responses and regulation of growth.4.constructed the plant expression vector PCAMBIA3301-ZmPTF1 and transfered it into tobacco by agrobacterium-mediated method.17 pieces of positive transgenic tobacco were gotten according to PCR identification. take southern hybridization analysis and RT-PCR on two pieces of normally growing transgenic tobacco of Tl generation and found that ZmPTF1 had already been integrated into the tobacco genome and could transcripe and inherite normally.5.Research on biological functions of ZmPTF1 transcription factor:compared to non-transgenic tobacco, the germination rate, germination potential and a-amylase activity of germinated seed of transgenic tobacco has been improved a lot, while the effect on fighting with ABA who inhibites germination decreases.The results above shows that ZmPTFl is active in corn’s hormone transduction, regulation of tissue differentiation, light signal transduction and stress response. Expression of ZmPTFl could cause the termination of dormancy of tobacco seeds and force the seeds germinate early, reduce the inhibition of ABA to seedling growth, increase the germination rate and germination potential of tobacco seeds.