Analysis Of MiR156 And Target Gene BpSPL9 In Betula Platyphylla

SPL is a plant-specific family of transcription factors that plays an important role in plant growth and development by regulating various physiological and biochemical processes.In this study,we constructed the plant expression vector of Betula albicans BpSPL9 gene and the overexpression vector of miR156.The phenotypic observation of the obtained transgenic lines was carried out and the function and regulation of miR156 and BpSPL9 genes were confirmed.The main studies include:The plant expression vector of Betula platyphylla BpSPL9 was constructed by Gateway method.The genetic transformation of Betula platyphylla was carried out by Agrobacterium tumefaciens-mediated zygotic embryo method.The transgenic plants were detected by PCR and quantitative PCR.The results showed that the BpSPL9 gene was successfully which is integrated into the plant genome.The results showed that the seedling height of transgenic lines was 30.34%lower than that of the control plants,6.24%lower than that of the control plants,and the number of leaves per plant was less than 26.03%.The leaf size of the leaves was lower than that of the control plants The leaf spacing was less than 42.87%and 50.91%,respectively.The aspect ratio of leaf was less than 27.21%and 27.99%,and the leaf spacing was mainly distributed between 8-14 mm,while the interval of non-transgenic control plants was between 10-14 mm The The results showed that the contents of GA3,IAA and 6-BA were lower than those of non-transgenic plants.The genetic transformation of Betula platyphylla was carried out by Agrobacterium tumefaciens-mediated zygotic embryo method.The transgenic plants were identified by PCR and quantitative PCR.The results showed that the birch miR156 was successfully integrated into the plant.Plant genome,and the transgenic plants had higher levels of miR156 than non-transgenic control plants.The results showed that the seedling height was 39.88%higher than that of the control plants,the diameter was 18.41%,the number of leaves per plant was more than 46.74%,and the leaf area of the seventh and eighth leaves was lower 58.92%and 75.60%,leaf aspect ratio higher than 4.47%and 4.53%,leaf spacing is mainly located in 6-8 mm,while the control plant spacing is mainly located in 10-14 mm,section spacing shorter.The results showed that the contents of GA3,IAA,BR and 6-BA were higher than those of non-transgenic plants,and chlorophyll content and anthocyanin content were significantly increased.There were 7 microRNA156 recognition loci in 12 SPL genes families of Betula platyphylla.Seven samples of SPL genes were quantitatively analyzed by quantitative analysis of miR156 overexpression transgenic lines.The results of quantitative PCR showed that the expression of BpSPL5,BpSPL8,BpSPL9,BpSPL11 and BpSPL12 genes decreased,which indicated that the five genes were regulated by miR156,and the miR156 and BpSPL9 genes were negatively regulated.