Soil cadmium (Cd) contamination threatens plant growth and agricultural productivity. Hibiscus syriacus L., valued for its ornamental, edible, and medicinal properties, is widely cultivated in Cd-contaminated areas of southern China.This study aimed to evaluate the effectiveness of nano-zinc oxide (nZnO) in alleviating Cd toxicity in H. syriacus, examining plant phenotypes, physiological and biochemical responses, root ultrastructure, and the accumulation and distribution of Cd and Zn within the soil-H. syriacus system. Pot experiments included Cd treatment (100 mg/kg) and combined soil or foliar applications of nZnO (50 and 100 mg/L), with plants harvested after 45 days. Compared to Cd treatment alone, the combined application of nZnO significantly increased biomass in roots, stems, and leaves, improved photosynthetic performance, osmotic regulation, and antioxidant levels, and mitigated root cell damage; Cd concentrated mainly in roots, and nZnO reduced root Cd levels by 0.24 %-9.06 %. SEM-EDS observations revealed that Cd predominantly accumulated in the root epidermis and cortex, with Cd stress leading to increased levels and localized aggregation of Cd in the xylem. By contrast, nZnO treatment alleviated this disruption. Leaf application of 50 mg/L nZnO showed the best results. These findings highlight nZnO as a promising nano fertilizer for alleviating Cd stress in plants.

Rising soil salinity poses significant challenges to Mediterranean viticulture. While some rootstocks effectively reduce salt accumulation in grafted scions, the mechanisms and performance of novel rootstocks remain largely unexplored. This study compared two novel M-series rootstocks (M2, M4) with established commercial rootstocks (1103 Paulsen, R110) to evaluate their physiological responses and salt tolerance under irrigation with varying salinity levels (0, 25, 50, and 75 mM NaCl) over 5 months. Growth parameters, photosynthetic efficiency, chlorophyll content (SPAD), ion homeostasis, and visual symptoms were monitored. Results revealed genotype-specific strategies: 1103 Paulsen exhibited robust photosynthetic efficiency and ion exclusion, maintaining growth and chlorophyll stability; M2 demonstrated superior biomass retention and moderate ion compartmentalization but showed reduced photosynthetic performance at higher salinity levels; R110 displayed effective ion management at moderate salinity but experienced significant growth reduction under severe stress; and M4 was the most sensitive, with severe reductions in growth and ion homeostasis. Organ-specific responses highlighted roots acting as primary ion reservoirs, particularly for sodium and calcium; leaves exhibited high potassium and chloride concentrations, critical for photosynthesis but prone to ionic imbalance under stress; and stems and wood played a buffering role, compartmentalizing excess sodium and minimizing damage to photosynthetic tissues. The reported findings provide valuable insights for rootstock selection and breeding programs, particularly for regions facing increasing soil and water salinization challenges.