The physiological importance of accumulation of cyclitols in Viscum album L.

Investigations of Viscum album on 16 different host species revealed an endogenous cyclitol pattern with pinitol, 1-O-methyl-muco-inositol, quebrachitol, chiro-inositol, an unidentified O-methyl-inositol and traces of ononitol. Host-specific cyclitols including bornesitol, quercitol, viburnitol, scyllo-inositol and the hexitol, sorbitol, were also stored in the mistletoe. The endogenous cyclitols were accumulated to such high concentrations that they made a large contribution to the osmotic potential. It was estimated that 22.6-43 % of mistletoe carbon is derived from the host.