Devenir de la putrescine‐1,4‐14C chez Glycine max

Fate of Putrescine‐1,4‐14C in Glycine max Putrescine‐1,4‐14C was supplied to young decotylized Glycine max (L.) Merr. cv. Chippewa plants growing under aseptic conditions on a liquid medium with nitrogen supplied either as ammonium chloride or nitrates. Whatever the source of nitrogen the diamine was quickly transformed to γ‐aminobutyric acid, succinic acid and malic acid; only a very minor part was utilized for the synthesis of polyamines. In the presence of ammonium chloride the putrescine catabolism may be slower than in the presence of nitrates. The results are explained by a weak isotopic dilution or by a diamine oxidase activity lower in “ammonium” plants than in “nitrate” plants; the two causes might co‐exist. The possibility of a diamine compartmentation has to be considered.