SPECIFIC RECOGNITION OF MUGINEIC ACID FERRIC COMPLEX BY BARLEY ROOTS

The uptake rate by iron-deficient barley roots (Hordeum vulgare, cv Minorimugi) from mugineic acid complexed with Fe(III) was much higher than corresponding complexes with Cu(II), Zn(II), Co(II) and Co(III). All mugineic acid analogues, regardless of their plant origins, enhanced iron uptake rate more than 100 times compared with synthetic chelators, EDTA and HEDTA (N-(hydroxyethyl)ethylenediamine-N,N,N'-triacetic acid). The complex formed by the chelating unit, 3'(S),3''(S)-N[3-carboxy-3-hydroxypropylamino)propyl] glycine with Fe(III) was a prerequisite for recognition of the complex by the specific transport system in barley roots.