THE CHEMISTRY OF BORON AND ITS SPECIATION IN PLANTS

The chemistry and usage of B, as well as its speciation in plants, are reviewed. In the context of biology, the chemistry of the surprisingl y rare element B is dominated by B-oxygen compounds. The occurrence, d istribution and chemistry of these compounds are briefly described. In addition, the chemistry involved in the interaction of B-O compounds with naturally occurring molecules, particularly polyhydroxy compounds , is summarised. The essentiality of B in plants has been known for 75 years, but the biomolecule(s) with which it interacts to cause its es sential function(s) remain largely unknown, although many have been su ggested. Recent research on the complexation, isolation and partial ch aracterisation of B complexes of polysaccharides, diols, and hydroxyac ids is outlined. The particular importance of B interactions with cell wall components, membranes, enzymes, sugars, and polyols is discussed .