Figure 2.

Labeling patterns of metabolites in S. alterniflora leaf sections supplied with [³⁵S]Met (77 Bq [10 nmol] per 0.2 g fresh weight). A, SMM, DMSHB, and DMSP. Labeling of DMSHB was below the detection limit (0.03 kBq) at all times. Inset shows [³⁵S]Met uptake from the medium. B, DMSP-amine. [³⁵S]DMSP-amine was identified by co-migration with authentic DMSP-amine in TLC (systems 1 and 2 of James et al. [1995]) and TLE (system 1 of James et al. [1995]), and by deamination to 3-dimethylsulfoniopropanol with nitrous acid (Zappia et al., 1969) as shown in the inset. The inset is an autoradiograph of a TLC-system 1 separation of [³⁵S]DMSP-amine from S. alterniflora, before (Con) and after (HNO₂) nitrous acid treatment; the positions of the origin (O), DMSP-amine (AM), and 3-dimethylsulfoniopropanol (OL) are marked. FW, Fresh weight.