There are many unanswered questions regarding the effect of antibiotics on plants. Previous results indicated that metal uptake in the model plant Arabidopsis was affected by the antibiotic kanamycin. We have proposed a model of metal uptake that involves three transporters: IREG1, WBC19, and FRD3 involved in the transport of Fe-Citrate, Fe-Nicotianamine and Citrate respectively. In this model, IREG1 is inhibited by kanamycin which results in Fe being transported mainly via WBC19. We would therefore expect an increased expression of WBC19 when kanamycin is present.To test this hypothesis we examined the expression of IREG1, WBC19, and FRD3 in Arabidopsis plants exposed or not exposed to kanamycin. RNA was isolated, reverse transcribed and TaqMan real-time PCR assays were set up to monitor the expression of the three genes. The results showed ~ 2 fold increase of WBC19 expression when plants were exposed to kanamycin. These results support our model and help us understand the relationship between antibiotics and metal uptake and shed light on the manner in which plants alter their transport mechanisms for metal uptake.
