Abstract

Abstract Root secretions of Fe‐stressed barley cultivars were subjected to TLC and HPLC examination for mugineic acid (MA) and analogous chelators (MAS). The results indicates that cv. Minorimugi secreted MA as the major component and 2'‐deoxymuglneic acid (DMA) as the minor one, whereas cv. Rikuzenmugi secreted mainly DMA and lesser amount of MA. MAS of these cultivars were identified by 1H‐NMR spectra. TLC examination suggested that cv. Tochigi goldenmelon, a two‐rowed barley variety, secreted chiefly an unidentified chelator, together with trace amounts of MA and DMA. The unidentified chelator was determined spectroscopically to be 3‐epihydroxymugineic acid (epi‐HMA). As compared with barley, corn and sorghum cultivars secreted much smaller amount of MAS (ca. 1/10 and 1/100 respectively) even under Fe‐stress conditions. The root washings of corn cultivars contained solely DMA, which was confirmed by means of TLC and NMR. Sorghum cultivars secreted DMA and smaller amount of a few unknown MAS. These results suggested that DMA is the most prevailing phytosiderophore in graminous plants.