Antimony (Sb) toxicity is a serious concern across the globe due to its hazardous impacts on plants and living organisms. The co-application of Chinese milk vetch (CMV) and biochar (BC) is a common agricultural practice, however, the effects of combined CMV and BC in mitigating Sb toxicity and bio-availability remain unclear. Therefore, this study investigated the impacts of CMV, rape straw biochar (RBC), and iron-modified biochar (FMB) and their combinations on rice productivity, physiological, and biochemical functioning of rice and Sb availability. Antimony toxicity caused a marked reduction in rice growth and productivity by decreasing chlorophyll, and anthocyanin synthesis, leaf water contents, osmolyte synthesis and antioxidant activities while, increasing hydrogen peroxide (H₂O₂), electrolyte leakage (EL), and malondialdehyde (MDA) production and Sb accumulation. Co-application of CMV and FMB increased biomass (29.50%) and grain yield (51.07%) of rice by increasing chlorophyll, and anthocyanin synthesis, leaf water contents, osmolyte synthesis, antioxidant activities, and decreasing production of H₂O₂, EL, and MDA and Sb accumulation in roots (90.41%) and shoots (96.38%). Furthermore, the combined addition of CMV and FMB also reduced the soil available Sb by 75.57% which resulted in less accumulation of Sb in plant parts and improved growth and yield. Given these facts, these findings indicate that co-application of CMV and FMB is a promising approach to remediate Sb-polluted soils and improve sustainable and safer rice productivity.

Antimony (Sb), a non-essential heavy metal, exerts severe toxic effects on the growth and development of plants. This study investigated the response of Brassica napus to Sb(III) stress under hydroponic conditions, focusing on Sb accumulation, physiological indexes, and transcriptome sequencing. Sb accumulation in different B. napus varieties showed consistent trends with physiological indicators (SOD, POD, CAT, MDA) in XZY512 root tissue. Both parameters increased with Sb concentration, reaching a peak at 75 mg/L before declining, suggesting that 75 mg/L Sb may be the optimal concentration for B. napus adaptation. Transcriptomic analysis identified 8,802 genes in root tissues and 13,612 genes in leaf tissues responsive to Sb stress, predominantly involved in oxidative stress responses, ABC transporters, glutathione metabolism, plant hormone signaling, and MAPK pathways. Physiological index changes were associated with upregulation of genes linked to antioxidants, including as CATs, GPXs, PERs, and GSTUs, in root tissues, whereas photosynthesis-related genes were mostly downregulated in leaf tissues. This work shows the potential of B. napus for phytoremediation efforts and offers important insights into its response mechanisms to Sb stress.

Antimony (Sb), a toxic metalloid, inhibits plant growth and threatens human health. Yellow Stripe-Like (YSL) proteins play crucial roles in metal ion transport and cellular homeostasis. While the OPT gene family has been characterized in some species, its genome-wide organization and functional involvement in Sb stress response remain unexplored in Brassica juncea. Here, we identified 47 high-confidence BjOPT genes and combined transcriptomic approaches to elucidate their regulatory roles under Sb stress. Phylogenetic tree, conserved motifs, and gene structure analyses consistently distinguished the BjOPT and BjYSL subfamilies. Comparative and collinearity analyses indicated that OPT genes in Brassica species (including B. rapa, B. nigra, and B. juncea) expanded independently of whole-genome triplication events. Transcriptomic profiling revealed significant enrichment of differentially expressed genes (DEGs) related to key biological processes (oxidative and toxic stress response, metal ion transport, and auxin efflux) and pathways (glutathione metabolism, MAPK signaling, and phytohormone transduction), highlighting their roles in Sb detoxification and tolerance. Notably, three BjYSL3 (BjA10.YSL3, BjB02.YSL3, and BjB05.YSL3) genes exhibited strong up-regulation under Sb stress. Heterologous expression in yeast demonstrated that both BjA10.YSL3 and BjB02.YSL3 enhance Sb tolerance, suggesting their potential role in transporting Sb–nicotianamine (NA) or phytosiderophore (PS) complexes. These findings advance our understanding of Sb tolerance mechanisms and provide a basis for developing metal-resistant crops and phytoremediation strategies.