Incorporation of 15N into allantoin in nodulated soybean plants supplied with 15N2

Incorporation of 15N into allantoin and allantoic acid in nodules was higher than that in roots. This confirms that nodules produce allantoin. The 15N concentration in allantoin was slightly higher than that in allantoic acid, suggesting that allantoin decomposed to allantoic acid. Allantoin and allantoic acid in nodules were translocated rapidly to roots.