“…Their involvement is implicated by apoplastic steps of post-phloem transfer in maize kernels, but symplastic roles of these transporters can also include vesicle-based transfer processes (Echeverría, 2000; Lalonde et al, 2004), transient storage by vacuoles (Eom et al, 2011), cellular efflux (Lalonde et al, 2004; Chen et al, 2010, 2012; Baker et al, 2012; Braun, 2012), or action as sensors (Kang and Turano, 2003; Lalonde et al, 2004; Slewinski, 2011; Aoki et al, 2012; Price et al, 2012). In maize kernels, prominent contributions are indicated for both sucrose and hexose transporters (Aoki et al, 2012), and the importance of SWEET-mediated efflux to diverse sinks (Chen et al, 2010, 2012), led to suggested roles in efflux to seeds (Braun, 2012).…”