Fig. 6.

Diurnal rhythm of phytosiderophore secretion (A) and ZmYS1 expression (B) in maize. Root exudates were collected from Fe-deficient maize seedlings every 3 h (sunrise 5:00 h) and roots and shoots were sampled at the same time point. The amount of phytosiderophore secreted was determined by HPLC according to Ueno et al. (2007). The expression level of ZmYS1 at different times was determined by quantitative RT-PCR. The relative mRNA levels in the roots at 6:00 h are shown. Data are means ±SD (n=3).