Bioinformatics analysis and expressed level of Auxin response factor genes in Scutellaria baicalensis

Auxin response factor (ARF) is an important transcription factor for auxin signal transduction pathway, which regulates virtually every aspect of plant growth and development from embryogenesis to senescence. Nine full-length genes of ARF transcription factors were obtained from transcriptome dataset of Scutellaria baicalensis Georgi using the bioinformatics methods. The nucleotide and protein characteristics, subcellular localization, senior structural domains and conservative forecasts of those ARF transcription factors were analyzed. The phylogenetic tree showed that the nine ARFs in S. baicalensis were clustered together with ARF transcription factors in Arabidopsis thaliana, Oryza sativa subsp. Japonica and Nicotiana attenuate. The results of gene expression showed that:① The expression levels of ARF1, ARF3, ARF4, ARF8, ARF20 and ARF24 were upregulated after 100 μmol·L^-1 GA₃ treatment. However, the expression levels of ARF6 and ARF18 were downregulated; ② Those ARF genes were mainly expressed in the flowers of S. baicalensis; ③ There was a significant correlation between ARF genes and the genes involved in flavonoid biosynthesis. Our results provide a basis for further understanding the molecular regulation mechanism of flavonoid biosynthesis in S. baicalensis.