Table III.

[³⁵S]DMSP-amine is not a metabolite of [³⁵S]SMM in grasses that lack DMSP

Species	Endogenous DMSP	35S Uptake	[35S]DMSP-amine	[35S]DMSP
	μmol g−1 fresh weight	kBq	Bq
S. alterniflora	29.0	18.3	389	8180
S. patens	<0.03	28.6	<30	<30
T. aestivum	<0.03	37.0	<30	<30
Z. mays	<0.03	36.6	<30	90
B. glaucescens	<0.03	36.3	<30	<30
O. compositus	<0.03	37.6	<30	<30
C. dactylon	<0.03	35.1	<30	<30
P. purpureum	<0.03	36.8	<30	70
C. selloana	<0.03	21.6	<30	<30

Leaf tissue (0.2 g fresh weight) of eight grasses shown not to accumulate DMSP was incubated for 6 h with 38.9 kBq (0.12 nmol) of [³⁵S]SMM; S. alterniflora was included as a benchmark. Uptake was calculated from ³⁵S disappearance from the medium. The radioactivity values shown are per 0.2 g fresh weight and have been corrected for recovery. Endogenous DMSP contents were determined on duplicate 30-mg fresh weight leaf samples. The comparison between S. alterniflora and S. patens was repeated, with similar results.