A schematic diagram of sucrose metabolism to illustrate the possible roles
of sucrose phosphate synthase (SPS) in growing pollen tube. CeS/CaS, cellulose
synthase and/or callose synthase; CWI cell wall invertase, MST, monosaccharide
transporter; SPS, sucrose phosphate synthase; Susy, sucrose synthase; SUT, sucrose
transporter; UGPG, uridinediphosphoglucose (adapted from Persia et al. [