Identification Of StGRAS Gene Family And Cloning Of StGAI Gene And Its Genetic Transformation In Potato

GRAS protein is a kind of transcription factor to higher plants.it is widely involved in plant stem elongation,root morphological development,seed dormancy,flower development,light response pathway and hormone regulation.At present,the study of GRAS transcription factors has not only been deeply studied in Arabidopsis thaliana but also been identified in other plants.The GRAS gene family and the function of subfamily genes were identified in maize,rice,tomato,pine and grape species.In this experiment,StGRAS transcription factors wereidentified in potato by bioinformatics.The expression of some family genes in different tissues and induced by different hormones was analyzed by Quantitative Real-time PCR?qRT-PCR?.A gene StGAI related to gibberellin signaling pathway was cloned by PCR,and the genetic transformation mediated by Agrobacterium tumefaciens was carried out by constructing overexpression vector and interfering expression vector,which laid a foundation for further study.The results are as follows:1.52 potato StGRAS transcription factors were identified in potato cultivar"Favorita"by bioinformatics method.It was found that most of potato StGRAS gene contained one exon,and almost 90%of the genes were single exon genes.All the genes were distributed on 12 chromosomes.StGRAS protein is generally composed of 300⁸00 amino acids.Phylogenetic tree analysis showed that 52 potato StGRAS genes could be divided into eight subfamilies.2.StGAI gene was cloned from potato by PCR,which belongs to DELLA subfamily of StGRAS gene family.The total length of the gene is 2293bp,which is located on chromosome 11.Its CDS region is 1767bp and encodes 588 amino acid residues.3.The potato StGAI gene cloned from PCR was used to construct the overexpression vector pBI121-StGAI using plant expression vector pBI121,the precursor primers of artificial miRNA interference expression vector were designed by WMD3 online website,and the artificial miRNA precursor fragments were obtained by PCR technique.The interference expression vector pCPB121-StGAI was constructed.Transgenic plants with overexpression and interference expression were obtained by Agrobacterium tumefaciens-mediated genetic transformation.4.Non-transgenic plants and transgenic plants were treated with GA₃.qRT-PCR analysis showed that the expression of StGAI gene in potato increased within 0⁴8 h.It was found that the expression of StGAI gene in transgenic plants was higher than that in non-transgenic plants,and the expression of StGAI gene in transgenic plants was lower than that in non-transgenic plants.