fagopyritol-b1 and stachyose

Developing garden pea embryos are able to take up exogenously applied cyclitols: myo-inositol, which naturally occurs in pea, and two cyclitols absent in pea plants: d-chiro-inositol and d-pinitol. The competition in the uptake of cyclitols by pea embryo, insensitivity to glucose and sucrose, and susceptibility to inhibitor(s) of H(+)-symporters (e.g. CCCP and antimycin A) suggest that a common cyclitol transporter is involved. Both d-chiro-inositol and d-pinitol can be translocated through the pea plant to developing embryos. During seed maturation drying, they are used for synthesis of mainly mono-galactosides, such as fagopyritol B1 and galactosyl pinitol A. Accumulation of d-chiro-inositol (and formation of fagopyritols), but not d-pinitol, strongly reduces accumulation of verbascose, the main raffinose oligosaccharide in pea seeds. The reasons for the observed changes are discussed.

Topics: Anti-Bacterial Agents; Antimycin A; Biological Transport; Carbonyl Cyanide m-Chlorophenyl Hydrazone; Disaccharides; Inositol; Oligosaccharides; Pisum sativum; Raffinose; Seeds; Time Factors; Uncoupling Agents