Original data

Under reduced light heterogeneity conditions, <i>P. quinquefolius</i> 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, <i>P. quinquefolius</i> integrated morphological and physiological traits, ultimately regulating root dry weight by reducing H₂O₂ content and increasing <i>Pn</i> and chlorophyll content. Light intensity significantly altered the properties of <i>P. quinquefolius</i> 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 <i>uncultured_Acidobacteria_bacterium</i>, <i>unclassified_Acidobacteriales</i>, and <i>unclassified_Leotiomycetes</i>) and denitrifying bacteria genera (such as <i>unclassified_Gemmatimonadaceae</i>, <i>Anaeromyxobacter</i>, and <i>Bradyrhizobium</i>). Soil chemical properties influenced <i>P. quinquefolius</i> growth by regulating photosynthesis and antioxidant physiological traits. Overall, under reduced light heterogeneity conditions, light intensity can directly or indirectly affect the soil-rhizosphere-<i>P. quinquefolius</i> system, but the underlying mechanisms require further investigation. This study expands our understanding of how light intensity under under forests light heterogeneity conditions regulates <i>P. quinquefolius</i> growth and is of significant importance for developing effective management strategies for under forests <i>P. quinquefolius</i> cultivation.