Seed Priming with\nDynamically Transformed Selenium\nNanoparticles to Enhance Salt Tolerance in Rice

Seed priming with nanomaterials is an emerging approach\nfor improving\nplant stress tolerance. Here, we demonstrated a mechanism for enhancing\nsalt tolerance in rice under salt stress via priming with nonstimulatory\nnanoparticles such as selenium nanoparticles (SeNPs), distinct from\nstimulatory nanomaterials. Due to the dynamic transformation ability\nof SeNPs, SeNP priming could enhance rice salt tolerance by mediating\nthe glutathione cycle to eliminate excess reactive oxygen species\n(ROS). During priming, SeNPs penetrated rice seeds and transitioned\ninto a soluble form (99.9%) within the embryo endosperm. Subsequently,\nthe soluble selenium (Se) was transported to rice roots and metabolized\ninto various Se-related derivatives, including selenomethionine (SeMet),\nNa<sub>2</sub>SeO<sub>3</sub> (Se IV), selenocysteine (SeCys<sub>2</sub>), and methylselenocysteine (MeSeCys). These derivatives significantly\nenhanced the root activities of key enzymes such as glutathione peroxidase\n(GSH-PX), glutathione reductase (GR), catalase (CAT), peroxidase (POD),\nand superoxide dismutase (SOD) by 24.97%, 47.98%, 16.23%, 16.81%,\nand 14.82%, respectively, thus reinforcing the glutathione cycle and\nROS scavenging pathways. Moreover, these alterations induced transcriptional\nchanges in rice seedlings, with genes involved in signal transduction,\ntranscription factors (TFs), ROS scavenging, and protein folding being\nupregulated, activating signal perception and self-repair mechanisms.\nThese findings offer valuable insights for the agricultural application\nof nanomaterials.