Respiration in support of N(2) fixation by rhizobia in legume root nodules depends on an adequate supply of O(2), but excessive O(2) can damage nitrogenase, the key enzyme. The movement of O(2) into and within the nodule is driven by gradients in the concentration of O(2) or in the oxygenation of the O(2)-carrier, leghaemoglobin. Steeper gradients may increase flux to the sites of respiration, ...

Tribes Trifolieae and Vicieae along with Cicereae and Galega (Galegeae) form a monophyletic group that has been designated informally as the “vicioid clade”. There is good support from analyses of various molecular data for the clade itself, but relationships of genera within the clade are not fully understood nor has monophyly of the tribes and genera been fully tested. Sequences of the plasti...

I N biennial white-blossomed sweetclover (Melilotus alba Desr.) , the B/b allelic pair controls .&glucosidase activity ( SCHAEFFER, HASKINS and GORZ 1960; HASKINS and GORZ 1965). Homogenates of BB and Bb plants are high and iatermediate, respectively, in /3-glucosidase activity. No activity has been detected in homogenates of bb plants. The precise effect of the alleles B and b on the enzyme ha...

Previous investigations have shown that CY4-labeled transcinnamic acid is rapidly converted to o-coumaric acid P-glucoside by shoots of Melilotus alba (white sweet clover) (1) and Hierochlod odorata (sweet grass) (2). This glucoside is then converted to coumarin (l-3), possibly by way of trans-cis isomerization of the glucoside to coumarinic acid P-glucoside. The small amount of radioactivity f...