ABSTRACT
The TTG1 transcription factor plays an important role in the formation of plant trichomes. Based on the R. rugosa transcriptome data, this study cloned a R. rugosa TTG1 gene, named RrTTG1, and carried out bioinformatics analysis and fluorescence quantitative analysis to explore the relationship between TTG1 gene and R. rugosa trichomes formation, in order to lay a good foundation to cultivate a thornless plant in the family Rosaceae. In this experiment, six hybrid cultivars of R. rugosa “Zizhi”, R. rugosa “Xizi”, R. rugosa “Tang fen”, R. rugosa “Hun chun”, R. rugosa “Zi long wo chi” and R. rugosa “Tian e huang” were used as experimental materials, and the cDNA full length of this gene was obtained by RT-PCR and RACE, and the full length of the cDNA was 1348 bp. After bioinformatics analysis, it is predicted that its molecular formula is C1723H2661N465O529S12, the molecular weight is 38.71 KB, and the isoelectric point is 5.00. Its instability index is 54.30, which belongs to unstable protein; and its hydrophilic amino acid distribution is relatively uniform, and the amount is larger than hydrophobic amino acid, which belongs to hydrophilic protein. Phylogenetic tree was constructed for the TTG1 gene. Evolutionary analysis indicated that RrTTG1 is closely related to the TTG1 protein of Rosaceae family, and has a close relationship with other families. The expression analysis showed that the expression of RrTTG1 protein was negatively correlated with the trichome content of R. rugosa stems and leaves. The expression levels of the three spiny varieties of R. rugosa “Hun chun”, R. rugosa “Xizi” and R. rugosa “Zi long wo chi” were lower, and the expressions of the three less thorn varieties of R. rugosa “Zizhi”, R. rugosa “Tian e huang” and R. rugosa “Tang fen” were higher. According to the above results, it was speculated that RrTTG1 is involved in the synthesis of R. rugosa trichomes and belongs to the negative regulation mechanism.