Distinct phytotoxicity mechanisms revealed by multi-omics and machine-learning of rice seedlings exposed to Pt nanoparticles or Pt ions

Dysregulated sequestration of platinum nanoparticles (PtNPs) in rice seedlings suggests possible nutrient homeostasis disruption, oxidative stress, and growth inhibition. However, the toxicological mechanisms of stress-responsive genes remain poorly understood. Here, for the first time, we have utilized a combination of multi-omics and machine learning approaches from a heteroid database to obtain the comprehensive and in-depth toxicity mechanism of PtNPs and Pt(II) on the rice seedlings growth. Multi-omics results showed that both Pt(II) and PtNPs caused phenylpropanoid pathway variations, and the methionine recovery process was confirmed to be responsible for PtNPs with more transcriptional changes in biological process and molecular function. PtNPs affected Mn homeostasis associated with peroxidase anti-oxidation, and then further affected the lignin biosynthesis processes. This study provides novel insights of distinct phytotoxicity mechanisms for rice seedlings exposed to PtNPs and Pt ions, having important implications for developing new strategies to improve the growth of rice seedlings.