Genetic variation of aliphatic glucosinolates in Arabidopsis thaliana and prospects for map based gene cloning

Abstract

Glucosinolates are thioglycosides found in families of the Capparales and a few other unrelated families. The glucosinolate molecule comprises two parts; a common glycone moiety and a variable aglycone side chain (Fenwick et al., 1983; Figure 1). The side chain may contain aliphatic, indolyl or aromatic groups and is derived from a corresponding α amino acid. In the leaves of Brassica, aliphatic glucosinolates derived from methionine are predominant, although other glucosinolates may occur. Following tissue damage, aliphatic glucosinolates are hydrolysed by endogenous β-thioglucosidase (‘myrosinases’) to give a complex mixture of products, of which D-glucose, sulphate and isothiocyanates are major components. The side chain of aliphatic glucosinolates is variable, and may include methylthioalkyl, methylsul phinylalkyl, alkenyl and hydroxyalkenyl homologues of propyl, butyl and pentyl glucosinolates.