Abstract
Arsenic is toxic to organisms. Arsenite (As(III)) and arsenate (As(V)) are the two main chemical forms of arsenic. As(III) and As(V) are taken up by bacteria, yeast and human via aquaglyceroporins and phosphate transporters, respectively. Plants also take up As(V) via phosphate transporters. However, the molecule(s) which mediates As(III) uptake in plants have not been identified.
We expected the loss-of-function mutant of As(III) transporter would be tolerant to As(III), as the As(III) could not enter roots. We searched As(III) tolerant mutant using EMS mutagenized Arabidopsis thaliana seeds and obtained 3 lines. We also analyzed tolerance of T-DNA mutants of NIPs, which is a homologue of aquaglyceroporins. Among the lines tested, only nip1;1 showed tolerant to As(III). We therefore sequenced the genomic region of NIP1;1 of As(III) tolerant mutants. All three mutants had a mutation in NIP1;1. These data indicate that NIP1;1 is involved in the As(III) uptake.
