Fig. 3

Functional analysis of the IbMYB340, IbbHLH2 and IbNAC56a or IbNAC56b genes using a transient expression assay in tobacco leaves. a The phenotype of tobacco leaves on the 7th day after infiltration: a, pSAK277; b, IbNAC56a; c, IbNAC56b; d, IbNAC56a + IbNAC56b; e, IbbHLH2; f, IbMYB340; g, IbMYB340 + IbNAC56a; h, IbMYB340 + IbNAC56b; i, IbMYB340 + IbbHLH2; j, IbMYB340 + IbbHLH2 + IbNAC56a; and k, IbMYB340 + IbbHLH2 + IbNAC56b. Scale bar = 1 cm. b Total anthocyanin contents in transformed leaves of tobacco. FW, fresh weight. c-d The color parameter L* and a*/b* ratio values were measured with a Minolta Chroma Meter and were used to indicate phenotypic changes. The values are presented as the means ± SDs (n = 3), and the uppercase and lowercase letters represent significant differences at P < 0.01 or P < 0.05, respectively