Unraveling tissue-specific molecular mechanisms orchestrating arsenic response processes in Pteris vittata through transcriptomic analysis

Pteris vittata remediates arsenic (As)-contaminated soils; however, the molecular mechanisms underlying the As management remain largely unknown. Therefore, in this study, we investigated As - related processes by conducting transcriptomic analysis on hydroponically grown P. vittata exposed to 500 ppb arsenate (AsV). Within 24 h, As was translocated to fronds, while As concentration among fronds differed (4.08-1323.35 µg/g-DW). Transcriptomic profiling of roots and fronds with high (PHAs) and low (PLAs) As concentrations revealed distinct As transport mechanisms. In the roots, the induction of PvPht1;3 and one PHO1 genes suggested the facilitation of AsV absorption, while ACR3 and POT genes were induced in both the roots and fronds. Notably, NRT2.5, NIP6;1, BOR2, and ABC transporter genes were specifically activated in PHAs, highlighting their potential roles in As hyperaccumulation. To our knowledge, this is the first report linking PHO1, POT, NRT2.5, NIP6;1, and BOR2 to As accumulation in P. vittata. Gene ontology enrichment analysis further emphasized a tissue-specific As response system. In the roots, differentially expressed genes (DEGs) associated with the activation of glutathione metabolic process, cell wall biogenesis, antioxidant response, and signal transduction pathways enabled a prompt response to As-derived stimuli, facilitating efficient As uptake and transport. In the fronds, DEGs related to cell wall modification, oxidative stress response, signal transduction, and active transport systems may contribute to As detoxification and hyperaccumulation. This study provides novel insights into the molecular basis of As uptake, transport, accumulation, and detoxification in P. vittata, providing valuable strategies for efficient phytoextraction via regulation of As metabolism.