Individual glucosinolates in various organs of the Columbia ecotype of A. thaliana during development with special emphasis on changes occurring during seedling germination and leaf development. The predominant seed glucosinolate; representing 41% of the total; has an aliphatic; butylbased side chain with a sulfur atom; but is not 4MSOB; the main glucosinolate found in the vegetative parts of the plant; but rather its reduced counterpart; 4 methylthiobutyl glucosinolate (4MTB). The seeds also contain greater amounts of the longer-chain aliphatic glucosinolates; such as 7-methylsulfinylheptyl- and 8-methylsulfinyloctyl- glucosinolate; than are found in the vegetative tissues. The 16 most abundant glucosinolates showed divergent patterns of change during this time course. During the first two days after planting; there was a general increase in all glucosinolates causing total concentration to rise to almost 1.60 nmol (seedling); approximately 3.3% of dry weight. After this point; specific increases were observed for glucosinolates associated with vegetative tissues. Increases of at least 6-fold were detected for 4MSOB; 5-methylsulfinylpentyl-; 1MOI3M and 4-methoxyindol-3-ylmethyl- glucosinolate; while 6 methylsulfinylhexyl-; 7-methylsulfinylheptyl-glucosinolate and I3M increased about 2-fold (Brown et al. 2003)