Two Trees would preserve the 80-foot-tall gantry cranes that once unloaded sugar and the 425-foot-long rail tracks on which they rolled.
Proteomic data [ 31] have provided evidence for a switch between sucrose synthase (SuSy) and vacuolar acid invertase (vINV) before véraison, thus supporting a supposed functional mechanism between SuSy and INV for unloading sugars during grape berry development and ripening, respectively [ 84], as demonstrated in tomato [ 85- 87].
In general, cytokinins may affect seed yield by enhancing sink strength and, consequently, increasing seed size, by up-regulating cell cycle related genes, through the action of sugar signalling and by enhancing phloem unloading and sugar import into the endosperm through enzymatic activity of cell wall invertase [ 12].
When Pepsi-Cola erected its big red neon sign in Long Island City, along the Queens side of the East River, in 1936, ships would steam up to the plant below it and unload sacks of sugar from Havana.
The process called phloem unloading allows sugars to be moved from sieve elements to recipient sink cells in the developing fruit [ 46].
The up-regulation of glycolysis related genes might also be related to phloem unloading of sugars and their storage in the vacuole.
Sucrose cleavage is usually associated with cell wall invertase activity at the onset of ripening, together with a shift towards apoplastic phloem unloading of sugars in berries during this same period of time [ 95].
Maize SUT, ZmSUT1, is responsible for sugar uptake into phloem in source tissues and sugar unloading from phloem into cells in sink tissues (Carpaneto et al. 2005).
Each played its own role in the journey of raw sugar unloaded from ships at the dock.
If we bear in mind the switch of the sugar unloading pathway at pre- véraison[ 50], it can be hypothesized that gluconeogenesis at early ripening stages is required to compensate the transient decay of sugars from the time that plasmodesmata are blocked to the full operation of the transporter-mediated apoplastic sugar unloading.
