Fig. 6.

Inhibition of FTR1 expression reduces R. oryzae ability to take up ⁵⁹Fe in vitro. (A) Plasmid pRNAi-pdc intron used to generate FTR1::RNAi strains. (B) RT-PCR showing lack of expression of FTR1 in R. oryzae transformed with RNAi plasmid (T₁ and T₃-T₅) compared to R. oryzae transformed with empty plasmid (C, control). Primers amplifying the 18s rDNA served as a control to demonstrate the integrity of starting sample and lack of PCR inhibitors. (C) A representative of the RNAi transformants demonstrated comparable growth to the R. oryzae M16 transformed with empty plasmid on CSM-URA media. (D) ⁵⁹Fe uptake by wild-type, R. oryzae M16 transformed with the empty plasmid, or one of the RNAi transformants. Germinated spores were incubated with 0.1 μM ⁵⁹FeCl₃ (a concentration in which high-affinity iron permeases are induced (Fu et al., 2004)). *P <0.05 when compared with R. oryzae wild-type or R. oryzae M16 transformed with empty plasmid. Data (n= 9 from three separate experiments) are expressed as medians ± interquartile ranges.