GLYCINEBETAINE IN OILSEED RAPE AND FLAX LEAVES - DETECTION BY LIQUID-CHROMATOGRAPHY CONTINUOUS-FLOW SECONDARY ION-MASS SPECTROMETRY

Glycinebetaine [betaine; (Me)(3)-N+-CH2-COO-] is likely to contribute to osmoregulation in those plants that accumulate significant amounts of it, and hence the interest in engineering its synthesis in 'nonaccu mulators'. Although only large amounts of betaine, as found in the che nopods Kochia scoparia (298.6 mu mol g(-1) dry wt) and Salicornia rubr a (162 mu mol g(-1) dry wt), would be physiologically significant, its presence in flax (Linum usitatissimum, 4 mu mol g(-1) dry wt) and rap eseed (Brassica napus; 4.9 mu mol g(-1) dry wt) indicates a genetic po tential for betaine synthesis in these important plants. The liquid ch romatography/continuous flow secondary ion-mass spectrometry method de scribed here offers a 10-fold increase in sensitivity over other metho ds, and allows for detection of as little as 5 pmol mu l(-1) of underi vatized betaine. The sensitivity of this method was further demonstrat ed by quantitation in the range of 50-1000 pmol mu l(-1).