Figure 4.

Functional analysis of MdMa12 through its overexpression in “Orin” apple calli. a. MdMa12-overexpressing apple calli and wild-type apple calli. b. Confirmation of transgene expression in transgenic apple calli by PCR amplification of a DNA template. A primer pair crossing an intron was designed to amplify the coding sequence and the genome sequence. Only the genome sequence was amplified for the wild-type control, whereas both the coding sequence and the genome sequence were amplified for the transgenic lines. c. Relative MdMa12 expression levels in apple calli. d. Malic acid contents in fresh apple calli. FW, fresh weight; CK, wild-type; T1, 2, and 3, transgenic lines 1, 2, and 3. ^**, significant difference from the wild-type control (P < 0.01; t-test).