Fig. 3

Carboxyfluorescein (CF) and [¹⁴C] Suc tracing support a predominantly symplasmic phloem unloading pathway in the storage root of cassava. a, b Transverse section anatomy of the storage root. c–f5 CLSM imaging of CF unloading during cassava root development. c–c3 Primary fibrous root. c2 Bright–field microscopy. c3 405nm excitation wave and bright–field microscopy. d–d5 Early stage storage root. e–e5 Middle stage storage root. f–f5 Late stage storage root. c1, d3–d5, e3–e5, f3–f5 Bright–fiield and 488 nm excitation wave microscopy. g CF fluorescence intensity of different root develop–mental stages. h The difference in the distribution density of [¹⁴C] Suc in cross sections of developmental roots at the three stages. The arrows indicate the vascular cambium. All of them with cropped edges and adjusted position using Adobe Photoshop CS6.0 software. Abbreviations, E, Early stage of storage root; M, Middle stage of storage root; L, Late stage of storage root; FBR, Primary fibrous root. Bar = 5 cm in a; Bar = 1 μm in b; Bar = 200 nm in c-f5; Bar = 1 cm in h