Abstract
Excess amount of divalent metals induces Fe-deficiency in plants (inducible Fe-deficiency), even though Fe is supplied enough. Conversely, Fe-deficiency induces excess accumulation of divalent metals other than Fe. These can be recognized as a result of the competition between Fe and the other metals to bind Fe-transporter; however, the details including the mechanism and the relative strength of the competition are still unclear. On the other hand, Ids2 is a gene related to the Mugineic acid bio-synthesis in barley, and is expressed only in roots at the Fe-deficiency status. These specificities are remained even when Ids2/GUS fusion gene system is transferred to tobacco plant, and thus can be utilized as a molecular marker to estimate the status of Fe-deficiency in plants. Here, we used this system to evaluate the relative strength of the competition to induce Fe-deficiency among some divalent metals. Results will be discussed with another physiological index.
