Difference in gene expression profiles between the two metal hyperaccumulators Noccaea japonica and Noccaea caerulescens ecotype Ganges under excess nickel condition

We compare global gene expression patterns between the two metal hyperaccumulator plants: Noccaea japonica, originating from nickel-rich serpentine soils, and Noccaea caerulescens (ecotype Ganges), origination from zinc/lead-mine soils, under excess nickel conditions. There were significant differences in the expression levels of genes involved in mineral transport, mineral homeostasis, and metal tolerance. Expression level of iron-regulated transporter 1 (IRT1), encoding the primary iron uptake transporter and also causing excess nickel absorption in Arabidopsis thaliana, is higher in N. japonica than in N. caerulescens, but NjIRT1 has a point mutation at the Asp-100, which is essential for iron transport, suggesting that NjIRT1 misses its transport functions for iron and possibly nickel.