FOLIAR RELEASE OF DIMETHYLSULFONIOPROPRIONATE FROM SPARTINA-ALTERNIFLORA

We report here that substantial quantities of dissolved dimethylsulfonioproprionate (DMSP) are released from live leaves of Spartina alterniflora in Georgia, USA salt marshes during tidal submergence. Mean monthly in situ foliar release rates varied from 0.092 +/- 0.050 to 0.291 +/- 0.289-mu-mol DMSP (g dry wt)-1 h-1. Estimates of tidal release of DMSP from creekbank stands of S. alterniflora varied from 46 +/- 3 to 684 +/- 411-mu-mol DMSP m-2 d-1 with annual losses of 114 mmol DMSP m-2 yr-1 (3.6 g S m-2 yr-1). Substantial quantities of DMSP accumulate on leaf surfaces. Extrafoliar DMSP accumulations on individual plants varied widely from undetectable to > 1-mu-mol (g dry wt)-1. Extrafoliar DMSP accumulations normalized to marsh surface area were generally less-than-or-equal-to 50-mu-mol m-2. Additions of DMSP to salt marsh creek water resulted in a rapid increase in dimethylsulfide (DMS) production. Foliar release of DMSP into tidal water from S. alterniflora may contribute to the production of DMS and related compounds in southeastern S. alterniflora marshes.