Chrysanthemums (Chrysanthemum × morifolium) are highly valued for their ornamental and economic benefits. However, the commonly used growing medium for chrysanthemums, peat, is not renewable, and peatlands are facing depletion. Therefore, it is important to find sustainable alternatives to peat. This study aims to evaluate the potential of rice husks and leaf mold mixed with peat and perlite in different ratios (10–20–30–40–80% v/v/v/v) as substitute materials for peat in chrysanthemum production. The study examines the physical and chemical properties of the different growing media ratios, as well as their effects on plant growth, development, and physiological indicators. The results of the experiment demonstrate that the different ratios of the cultivation substrate significantly influence the physical and chemical properties of the growing medium, as well as the growth and physiological indicators of chrysanthemums. A 20–30% proportion of rice husks and leaf mold promotes the growth and photosynthetic activity of chrysanthemum cuttings, resulting in increased plant height, leaf area, total chlorophyll content, and net photosynthetic rate. The mixed substrates (10–40%) maintain suitable pH levels, electrical conductivity (EC), and nutrient content (nitrogen, phosphorus, and potassium). However, an 80% ratio of rice husks negatively affects plant survival and growth due to elevated EC and potassium levels. In conclusion, a peat medium containing 20% rice husks and leaf mold provides a more favorable cultivation substrate for producing high-quality chrysanthemums while promoting sustainable horticultural practices.

Cadmium (Cd) is a highly toxic heavy metal that severely impairs plant growth and poses ecological and health risks. Chrysanthemum indicum (L.), a dominant species in Cd-contaminated regions, represents a valuable germplasm for phytoremediation. In this study, we cloned and characterized CiWRKY50, a WRKY transcription factor containing a conserved WRKY domain and C2H2-type zinc finger. CiWRKY50 was localized to the nucleus but lacked intrinsic transcriptional activation activity. Overexpression of CiWRKY50 in Arabidopsis thaliana and C. indicum significantly enhanced Cd tolerance, as shown by reduced root Cd accumulation, improved transport efficiency, lower ROS and MDA levels, and increased chlorophyll, proline, and soluble protein contents. Antioxidant enzyme activities and Cd-chelating compounds (GSH, NPT, PCs) were also upregulated. Furthermore, combined Cd and ABA treatments promoted Cd sequestration in roots and activated ABA-responsive genes (CiABF1, CiABF2, CiABF4), alleviating shoot toxicity. These findings indicate that CiWRKY50 enhances Cd tolerance in association with enhanced ABA-mediated signaling and redox homeostasis, providing new insights for breeding Cd-resistant plants and improving phytoremediation strategies.