Wheat PHT1;9 acts as one candidate arsenate absorption transporter for phytoremediation

Arsenate (AsV) is one of the most common forms of arsenic (As) in environment and plant high-affinity phos-phate transporters (PHT1s) are the primary plant AsV transporters. However, few PHT1s involved in AsV ab-sorption have been identified in crops. In our previous study, TaPHT1;3, TaPHT1;6 and TaPHT1;9 were identified to function in phosphate absorption. Here, their AsV absorption capacities were evaluated using several experiments. Ectopic expression in yeast mutants indicated that TaPHT1;9 had the highest AsV ab-sorption rates, followed by TaPHT1;6, while not for TaPHT1;3. Under AsV stress, further, BSMV-VIGS-mediated TaPHT1;9-silencing wheat plants exhibited higher AsV tolerance and lower As concentrations than TaPHT1;6- silenced plants, whereas TaPHT1;3-silencing plants had similar phenotype and AsV concentrations to control. These suggested that TaPHT1;9 and TaPHT1;6 possessed AsV absorption capacity with the former showing higher activities. Under hydroponic condition, furthermore, CRISPR-edited TaPHT1;9 wheat mutants showed the enhanced tolerance to AsV with decreased As distributions and concentrations, whereas TaPHT1;9 ectopic expression transgenic rice plants had the opposite results. Also, under AsV-contaminated soil condition,

Automated summary

Arsenate (AsV) is a common form of arsenic (As) in the environment, and high-affinity phosphate transporters (PHT1s) are the main transporters for AsV in plants. However, few AsV transporters have been identified in crops. In this study, TaPHT1;9 and TaPHT1;6 were found to have higher AsV absorption capacities compared to TaPHT1;3. The results indicate that TaPHT1;9 and TaPHT1;6 are capable of absorbing AsV, with TaPHT1;9 showing higher activity.