Enhancing the Growth Performance, Cellular Structure, and Rubisco Gene Expression of Cadmium Treated Brassica chinensis Using Sargassum polycystum and Spirulina platensis Extracts

Cadmium (Cd) is one of the highly toxic, non-essential heavy metals that inhibit plant growth and development by prompting chlorophyll loss affecting photosynthetic activities. This study investigated efficacy Spirulina platensis Sargassum polycystum extracts in alleviating Cd stress Pak Choi at morpho-biochemical, anatomical, molecular levels. Different concentrations (0, 25, 50, 100 mL/L) S. polycyctum (SAR), (SPI), a mixture both (SS) were exposed to mg/kg Cd-contaminated seedlings. Non-Cd-treated without algal assigned as positive negative controls, respectively. The results showed application increased height, fresh weight (FW), dry (DW) extract level increased. was greatest 100SS with 37.51% (shoot length), 68.91% (root 110.8% DW), 216.13% while an increase 176.7% FW) 256.9% seen 100SPI treatment. Chlorophyll a, b, carotenoid, fluorescence significantly after treatment 100SS. Antioxidant enzymes CAT, APX, POD, protein mL/L 28.13% (100SS), 36.40% (100SAR), 46.92% 153.48% same also identified dominate root structures such total length, surface area, projected diameter, volume, tips, fork number. highest reduction content shoot observed 53.8% 39.88% decrease, Increasing concentration improved leaf histological characteristics substantially, stomatal size opening, mesophyll tissues, vascular bundles. In addition, fold change ratio Rubisco gene noticeably greater than other treatments, 0.99 when compared untreated sample. present illustrated have potential effectively alleviate plants, especially mixture. These findings contribute sustainable strategies for mitigating toxicity crops.