Transport, storage and turnover

Water soluble compounds are usually stored in the vacuole (Matile, 1978, 1984 Boiler and Wiemken, 1986 Wink, 1993, 1997 Terasaka et al, 2003 Kutchan, 2005 Yazaki, 2005, 2006) (Table 1.2), whereas lipophilic substances are sequestered in resin ducts, laticifers, glandular hairs, trichomes, thylakoid membranes or on the cuticle (Wiermann, 1981 Kutchan, 2005) (Fig. 1.5). 

As mentioned previously, most substances are s)mthesized in the cytoplasm, the ER or in organelles, and, if hydrophilic, they are exported to the vacuole. They have to pass the tonoplast, which is impermeable to many of fhe polar SM. For some alkaloids and flavonoids, a specific transporter 

Cardiac glycosides (lanatoside A, C purpureaglycoside A) Saponins (avenacosides) 

Nitrogen-containing compounds (excluding alkaloids) Cyanogenic glycosides (linamarin) 

Many alkaloids, NPAAs, saponins, glycosides, flavonoides, anthocyanins, tannins, cyanogens, glucosinolates, amines 

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