Transmethylation from methionine into choline in the intact mycelia of Pyricularia oryzae and the effects of fungicides on it were observed by 13C NMR. P. oryzae was incubated with [methyl-13C]methionine. After 3 hr incubation, signal at 54.9 ppm, corresponding to the chemical shift of -N-CH3, was observed in the 13C NMR spectrum of the mycelia and its intensity increased with incubation time up to 24 hr. From the resultant mycelial cells, choline and phosphatidylcholine were isolated, and labeled N-methyl group was found in them. The signal intensity of the N-methyl was most remarkable in the water soluble fraction, suggesting that the signal at 54.9 ppm in the spectra of the mycelia was attributable to N-methyl group of choline. The methyltransfer from [methyl-13C]methionine into choline could be observed by 13C NMR. When 100 ppm of IBP was added to the incubation mixture, this methyltransfer was inhibited during 3 to 6 hr. Addition of 40 ppm of isoprothiolane had a similar effect.

13C NMR spectra of intact mycelia of Pyricularia oryzae, Botrytis cinerea, and five species of Pythium were measured. Sharp signals assigned to trehalose, mannitol and triglycerides in the cytoplasm were observed in the spectra of P. oryzae and B. cinerea. (l->3)-/?-Glucan and triglycerides were detected in all species of Pythium examined, and trehalose was observed in P. intermedium, P. ultimum and P. spinosum. In addition, glucose was detected in the latter two species. No remarkable signals from proteins, nucleic acids, membranelipids or cell wall polysaccharides wereobserved. Recently NMRspectroscopy has been applied to the fields of biochemistry, physiology and medicine. One well-known application is 31P NMRof intact cells and organs.1* Energy metabolism in living cells can be observed by following changes in the 31P NMRspectra due to ATP, ADPand sugar phosphates. It is possible to estimate the pHof the matrix of the cytoplasm or organelles by examining the chemical shift of inorganic phosphate. Various samples, microorganisms, cultured cells and