Original data

Under reduced light heterogeneity conditions, P. quinquefolius grown under 13.1% light transmittance exhibited the greatest root dry weight compared to 0.7%, 6.4%, and 19.8% light transmittance conditions. At 13.1% light transmittance, P. quinquefolius integrated morphological and physiological traits, ultimately regulating root dry weight by reducing H₂O₂ content and increasing Pn and chlorophyll content. Light intensity significantly altered the properties of P. quinquefolius rhizosphere soil and microbial diversity and community structure. A 13.1% light transmittance had a positive effect on both. Notably, it enhanced S-UE activity, pH, and AN content, as well as the relative abundance of pH-related microorganisms (such as uncultured_Acidobacteria_bacterium, unclassified_Acidobacteriales, and unclassified_Leotiomycetes) and denitrifying bacteria genera (such as unclassified_Gemmatimonadaceae, Anaeromyxobacter, and Bradyrhizobium). Soil chemical properties influenced P. quinquefolius growth by regulating photosynthesis and antioxidant physiological traits. Overall, under reduced light heterogeneity conditions, light intensity can directly or indirectly affect the soil-rhizosphere-P. quinquefolius system, but the underlying mechanisms require further investigation. This study expands our understanding of how light intensity under under forests light heterogeneity conditions regulates P. quinquefolius growth and is of significant importance for developing effective management strategies for under forests P. quinquefolius cultivation.