Genome-Wide Identification And Response To Tuber Dormancy Release Of StTCP Transcription Factors In Potato (Solanum Tuberosum L.)

The formation and release of potato tuber dormancy is the result of the regulation of multiple hormones and genes.In most cases,transcription factors are the upstream of the signaling pathway during signal transduction of plant's growth and metabolism,they play vital roles in regulating the expression of related genes.According to the results of RNA-seq in our laboratory,it has been found that many transcription factors take part in the regulation of potato tuber dormancy release.Plant TCP transcription factor is a peculiar transcription factor of plants,it is closely related to the proliferation and growth of plant cells,and mainly takes part in the regulation of plant growth and development,such as branching,leaf development,morphogenesis of shoot organs,flower development,seed germination and hormone pathways.In this study,a total of 31 non-redundant TCP transcription factors of potato were identified and divided into two subfamilies including three distinct subclades.Genes structure and the expression of these genes were analyzed by bioinformatics methods.Potato(Solanum tuberosum L.)cultivar ‘Favorita' was used as plant materials,using potted seedlings as research materials in hormone response.To perform the tuber dormancy analysis,the‘Favorita' tubers with uniform sizes were harvested from the experimental farm of Weiyuan County in Gansu Province of China.All TCP transcription factor family gene expression analysis was carried out by using qRT-PCR.The main findings are as follows:1.Analysis of differential expression genes enriched in the process of potato dormancy release has found that DNA replication and metabolic activity in dormancy tuber cells were inhibited,after dormancy release,related genes begin transcripting and DNA replication activated.After the emergence of differentiated buds,the genes associated with photosynthesis were widely expressed,metabolism begins and products organic matter using tuber storage substances and storage energy to provide a basis for the development of differentiated buds.And many differential expression transcription factors with increased expression were found during the release of potato tuber dormancy.2.To get a complete list of TCP genes in potato,Hidden Markov Model searches were performed using TCP domain(PF03634)as query sequences.As a result,a total of 46 StTCP genes were extracted from potato genome.These 46 StTCP genes were submitted in the PGSC database to remove redundant genes,and the presence and completeness of their TCPdomain were checked by submitting StTCP amino acid sequences to the InterPro.As a result,15 redundant StTCP genes were excluded and finally 31 non-redundant StTCP genes were identified in potato genome.3.According to evolutionary and syntenic analysis,we found that the StTCP transcription factor family gene could divide into three subgroups of two sub-families and had many syntenic genes with Arabidopsis and tomato.Protein motif analysis demonstrated that StTCPs in the same subclade shared similar conserved motif structures.Gene structure analysis showed that almost all StTCPs displayed highly conserved exon-intron organization.The analysis of StTCP gene promoter regions revealed that multiple cis-acting elements were involved in plant growth,development,hormone responses as well as stress responses.4.The result of StTCP gene expression profiles showed they had tissue-specific expression patterns which implied their differentiated functions.According to the results of quantitative RT-PCR(qRT-PCR),7 StTCP genes were dramatically upregulated during the release of tuber dormancy and some specific StTCP genes were strongly responded to different abiotic stresses and multiple hormones.Combined with Syntenic analysis,GO and KEGG annotations and expression profile we found StTCP15 and StTCP23 may have function in the activation of promoting embryonic growth during potato tuber dormancy release via the gibberellin signaling pathway.5.StTCP23 gene was amplified in the potato cultivar‘Favorita'cDNA,and inserted into the linearized potato over-expression vector pBI121 by homologous recombination method.Constructed the pBI121-TCP23 over-expression vector.