The degradation of canavanine by jack bean cotyledons

Germinating jack bean cotyledons liberated (14)CO2 when fed (14)C-guanidoxy-canavanine but did not accumulate any (14)C-compounds other than the applied canavanine. This suggested that the canavanine was being degraded by the action of canavanase to canaline and urea, the urea then being converted to ammonia and carbon dioxide by the action of urease. Hydroxyurea and acetohydroxamic acid (both inhibitors of urease activity) strongly inhibited the liberation of (14)CO2 from (14)C-guanidoxy-canavanine by the cotyledons but neither compound induced the accumulation of (14)C-urea within the tissues. This inhibitory action of hydroxyurea on (14)CO2 output was thought to be due at least in part, to this inhibition of canavanase activity.