Fig. 4

Changes in wax load, composition, cuticle wax crystal morphology, and expression of wax-related genes in WT and MdMYB30 ectopic expression plants. a Total cuticular wax content of stems, calculated per unit area of 6-week-old Arabidopsis from WT and MdMYB30 ectopic expression lines. b Cuticular wax composition of 6-week-old Arabidopsis stems for the WT and MdMYB30 ectopic expression lines. c Wax crystal morphology of 6-week-old Arabidopsis stems from the WT and MdMYB30 ectopic expression lines detected by scanning electron microscopy (scale bars: 10 μm). The surface of the MdMYB30 ectopic expression lines were covered with wax crystals and wax deposition, whereas the wild-type surface showed only a small amount of wax deposition (arrows point to the epicuticular wax crystals). Wax crystals were monitored at ×1000/× 25000 magnification (white boxes point to the magnified regions). d The expression of wax-synthesis-related genes in MdMYB30 ectopic expression and WT Arabidopsis. e ChIP analysis with nuclei extracted from crosslinked 15-day-old apple calli of the empty vector (EV) and MYB30-GFP OE. The Md18S gene was used as a control, which provided the background level for the ChIP samples. P1, P2 and P3 represent putative binding MYB cis-elements in the MdKCS1 promoter, respectively. Error bars represent standard deviation (SD; n = 3). Data are mean ± SD of three independent replicates. Different lowercase letters indicate significant differences at P < 0.05