Abstract
Iron-uptake mechanism in higher plants is mainly divided into two: one consists of H+-excretion, reduction of ferric ion and the ferrous ion uptake (Strategy 1). The other one consists of biosynthesis/excretion of Mugineic acids and uptake in the conjugation with ferric ion (Strategy 2). Here, we used two genes representing those strategies, NtIRT1 and HvIDS2, to examine the expression specificity responding to three types of iron-deficiency (1. transplant to Fe-deficiency condition after grown in a normal condition; 2. transplant to Fe-deficiency condition with washing out the apoplasmic Fe; 3. transplant to cadmium added Fe-deficiency condition) in the respective native mother plant. Results demonstrated that NtIRT1 did not express without apoplasmic Fe even the plant was in a Fe-deficiency condition, while HvIDS2 expressed whenever the plant was in a Fe-deficiency condition. Result from the further experiment using a transformed tobacco, which expressing HvIDS2p/GUS fusion gene, will be also discussed together.
