The effect of 3,4-DHP on the surface localized JIM11 epitope in banana somatic embryos. (a) and (b) Control embryos (arrows point to the regularly organized epidermis covered by ECM with strong JIM11 fluorescence. (c) and (d) Five-week-old embryos maintained on RD1 medium supplemented with 3,4-DHP. Arrowheads indicate disintegration of epidermis and formation of callus-like tissue at embryo surfaces. Note disruption of JIM11-positive ECM. Bars, 100 μm.