The potential application of the endophyte Phomopsis liquidambari to the ecological remediation of long-term cropping soil

A broad-spectrum endophyte, Phomopsis liquidambari, was used as a microbial agent to determine the effects of rapid litter decomposition on soil phenolic compounds dynamics, the soil microbial community balance and plant growth. The litter decomposition ratio was closely correlated with lignin degradation. The soil phenol concentration increased with the acceleration of litter decomposition after the first 30 days and later decreased to below the initial level. Based on denaturing gradient gel electrophoresis (DGGE) analysis, soil bacteria, especially gram-negative bacteria that have the potential to degrade aromatic compounds, were found in high abundance when the soil phenol concentration was high. When the phenolic concentration decreased, soil fungi increased in abundance. With fungal application, seed germination significantly increased to 69.87% and seedling growth was enhanced. Rapid litter decomposition by Pho. liquidambari initially led to higher releases of phenolic allelochemicals, which led to the enrichment of soil gram-negative bacteria. In addition, increased soil nutrients and temporarily higher concentrations of phenolics from litter decomposition strengthen seedling growth, suggesting that the endophytic fungus Pho. liquidambari is a suitable candidate for remediation of long-term cropping soil.

► Pho. liquidambari decomposition increase soil phenolics release within 30 days.
► Pho. liquidambari decomposition effectively reduces soil phenolics within 60 days.
► Soil gram-negative bacteria were stimulated by high concentration of phenolics.
► Pho. liquidambari promote non-host plant A. lancea growth in vitro.