Table 1

Primers used in this study"

Fig. S1

Growth vigor of plants with purple and green petioles"

Fig. 1

Characterization of petiole color, growth potential, and InDel marker identification at key loci in the first self-generation of SC124 A: segregation of purple and green petioles in the first self-generation of SC124. B: segregation of purple and green juvenile leaves in the first self-generation of SC124. C: comparison of average stem diameter between purple-petiole and green-petiole plants. Lowercase letters above error bars indicate significant differences at the 5% level. D: comparison of average plant height between purple-petiole and green-petiole plants. Lowercase letters above error bars indicate significant differences at the 5% level. E: comparison of the promoter region sequences between plants with purple and green petioles. The red box indicates the differential sequence between purple and green petioles. F: schematic diagram of primer design based on the promoter region of purple petioles. G: verification of the differential sites in the promoter regions of purple and green petioles using PCR technology."

Table S1

Survey of plant height and stem diameter in SC124 self-separated population"

Fig. 2

Characterization of MePAP2 A: phylogenetic analysis of MePAP2 and protein sequences of 10 representative anthocyanin-promoting MYB transcription factors from plant species. Accession numbers of other species: AtPAP1 (NP_176057.1), AtPAP2 (NP_176813.1), AtMYB113 (NP_176811.1), FaMYB10 (USN17647.1), MdMYB9 (NP_001280749.1), VvMYBA1 (XP_010664911.1), VvMYB5b (NP_001267854.1), VvMYB114 (XP_034707784.1), and MdMYB11 (NP_001280958.1). B: sequence alignment of MePAP2 with its homologs in other plant species. Gray boxes indicate the R2 domain, black boxes denote the R3 domain, and the red box highlights the bHLH-interacting motif."

Fig. 3

Screening and Identification of MeERF6 A: screening of AbA background concentration in yeast one-hybrid (Y1H) for green petiole and purple petiole. B: identification through streaking purification of yeast colonies from green petiole and purple petiole. C: prediction of the conserved domain of MeERF6 using the online conserved domain prediction website smart. D: subcellular localization of MeERF6 protein in tobacco. The scale bar is 50 μm."

Fig. 4

Expression profiles of MeERF6 and MePAP2 in response to low-temperature treatment A: transcriptional activity analysis of MePAP2 in three different tissue parts (petiole, stem, and leaf) under 4℃ low-temperature treatment. Lowercase letters above the error bars indicate significant differences at the 5% level. B: transcriptional activity analysis of MeERF6 in three different tissue parts (petiole, stem, and leaf) under 4℃ low-temperature treatment. Lowercase letters above the error bars indicate significant differences at the 5% level."

Fig. 5

Yeast one-hybrid, dual-luciferase assay, and in-vivo imaging were used to verify the interaction between promoters and transcription factors A: the yeast one-hybrid dot-blot experiment verified the interaction between MeERF6 and MePAP2pro in yeast. B: the in-vivo imaging (LCA) experiment verified the interaction between MeERF6 and the promoter region of the green-petiole MePAP2 in tobacco. MePAP2pro + MeERF6 was the experimental group. C: the in-vivo imaging (LCA) experiment verified the interaction between MeERF6 and the promoter region of the purple-petiole MePAP2 in tobacco. MePAP2pro + MeERF6 was the experimental group. D: dual-luciferase assay determined the regulatory mode of MeERF6 on the promoter regions of the green-petiole and purple-petiole MePAP2. MePAP2pro + MeERF6 was the experimental group. Data represent the mean of three independent biological replicates. Lowercase letters above the error bars indicate significant differences at the 5% level."