Iron Chlorine e6 Improves Soybean Yield by Maintaining Chlorophyll Stability and Promoting Carbohydrate Accumulation Under Saline-Alkali Stress

It restored antioxidant indices, reduced the accumulation of malondialdehyde (MDA), H₂O₂, and O₂⁻, increased leaf area, and elevated chlorophyll content. Combined transcriptomic and metabolomic analyses identified 2896 and 3530 differentially expressed genes (DEGs) in HN95 and HF50, respectively, under ICe6 vs SA treatment. These DEGs were mainly enriched in photosynthesis and chlorophyll metabolism pathways such as GO:0009765 (photosynthesis, light harvesting).

Differentially accumulated metabolites were mainly enriched in the isoflavonoid biosynthesis pathway (flavonoids enhance antioxidant capacity) and the amino acid biosynthesis pathway (determines chlorophyll precursor synthesis efficiency). These results indicate that ICe6 primarily regulates the expression of chlorophyll metabolism-related genes, light energy capture, and chlorophyll biosynthesis, thereby increasing chlorophyll content, promoting carbohydrate accumulation, and ultimately improving soybean yield under saline-alkali stress (HN95: +5.74%; HF50: +5.83%).