Regarding figure 6B, I am a little confused about what it is trying to communicate. The figure supports the zinc-depend concentration of MtZip6, but it was a little hard to understand the rationale to test different concentration of zinc. Since figure 6a showed that zinc concentration in WT nodules is lower compared to RNAi nodules, but in figure 6c Zinpyr-1 signal is higher in WT than in RNAi nodules. I was expecting to observe the same zinc concentration pattern than in figure 6a.
Uncharacterized transporters are denoted by question marks. I think it is helpful for the reader to be able to look at a summary model but the question marks in the suggested transporters might be misleading. After all, it is just a suggested model which summarizes what we know so far from studies in other species; it is obvious that further studies are needed to validate it. Some of the not yet characterized transporters were eliminated in the final publication, helping to streamline main findings.