Abstract
We previously identified a molybdate transporter, MOT1, from Arabidopsis thaliana. Here, we studied roles of MOT2, a MOT1 paralog, in molybdenum (Mo) transport. Transcripts of MOT2 were detected both in shoots and roots, and relative transcription levels of MOT2 were two times higher than that of MOT1. The levels of MOT2 transcript accumulation in plants grown under limited Mo conditions were not significantly different from that in plants grown under sufficient Mo conditions. Mo concentration in shoots of a T-DNA insertion mutant for MOT2 was reduced, and under limited Mo conditions, the growth of mot2 mutant plants was suppressed. The growth was partially restored by supplementing ammonium. Expression of MOT2 increased Mo concentration of yeast cells. Taken together, we suggest that MOT2 encodes a functional Mo transporter required for normal growth under low Mo conditions.
