Figure 2.

IRT1 and IRT2 promotor activity evaluated by GUS fluorometry. (a) Activity of IRT promoters in different organs of three lines growing in soil substrate. Wild represent extracts from nontransgenic plants. (b) Iron deficiency in the medium increases the activity of IRT1 promotors in all organs and activity of IRT2 promotor in roots but not in shoots. (c) Activity of IRT1 promotor in all organs and activity of IRT2 in roots are iron concentration-dependent. Their activities decrease when iron becomes available. (d) GUS protein analysis by western blotting confirming regulation of promotors by iron