Studies on absorption, conversion of sulfate by rape seedling and accumulation of glucosinolate in rape seed by using 35S

The seedlings grown in sandy culture absorbed 35SO42- from cultural solution rapidly and the 35S was incorperated into glucosinolates, amino acids and proteins. Percentage of glucosinolates-35S in extractable 35S with 70% methanol declined and those of amino acid-35S rose regularly with time after labelling. The relative content of 35S incorperated into bound constituents as well as extractable components was constant after 5 days of labelling. From two weeks after flowering, the relative content of GS-35S in pods and seeds increased linearly with time until eight weeks after flowering when all 35S extracted with 70% methanol in seeds were in form of glucosinolate. The amount of 35S-GS per pod increased linearly from the first week to the eighth week after flowering. It seems that the accumulation of GS in seeds is related to the accumulation of dry matter in seeds