the results of experiments in which intact plants of lemna paucicostata were labeled with either l- [ ( 3 ) h ( 3 ) c ] methionine , l- [ ( 14 ) ch ( 3 ) ] methionine , or [ 1,2- ( 14 ) c ] ethanolamine support the conclusion that growth in concentrations of choline of 3.0 micromolar or above brings about marked decreases in the rate of biosynthesis of methylated forms of ethanolamine ( normally present chiefly as phosphatidylcholine , with lesser amounts of choline and phosphocholine ) .
C0008405
choline
C0031716
phosphocholine