Fig. 10.

Summary of sucrose transport in developing female florets before an embryo is present in maize. Phloem contents including sucrose (Suc) are moved to phloem terminus where they are released non-selectively through the red plasma membrane (black dot with channel). In the apoplast, the sucrose is hydrolysed to glucose (Glu) and fructose. The nucellus selectively absorbs glucose (black dot), and the pedicel tissues around the phloem termini also absorb glucose but convert it to starch (dashed arrow). Although the embryo is absent, this scheme is similar to that when an embryo is present, according to Patrick and Offler (1995, 1996).