Figure 4.

Expression Analysis of NRAMP1.

(A) Relative NRAMP1 transcript abundance, determined by real-time RT-PCR, in roots and shoots of wild-type plants grown in vitro for 2 weeks either in Mn-replete medium or in Mn-free medium; NRAMP1 mRNA level in the nramp1-1 (nr1-1) mutant is shown as a negative control.

(B) Kinetics of the response of NRAMP1 to Mn deficiency and Mn resupply monitored by real-time RT-PCR in roots of plants grown in vitro. Data are means of one representative experiment ([A], n = 3; [B], n = 4). Error bars represent sd.

(C) Histochemical staining of GUS activity in the root of an Arabidopsis line transformed with the construct ProNRAMP1:GUS. (a) and (b) GUS staining of the primary root of 2-week-old plants grown in vitro either in Mn-replete conditions (a) or in Mn-free medium (b); 1, elongation zone; 2, absorption zone. (c) to (e) Cross sections of a root grown and stained as in (b) in the elongation zone (c), in the mature zone (d), or at the level of a root hair (e).