Aboveground endophyte (Epichloe? coenophiala) symbiosis enhanced rhizosphere enzyme activities of tall fescue (Festuca arundinacea)

Epichloe center dot coenophiala fungal endophytes form aboveground symbiotic relationships with many types of grasses. The objective of this study was to investigate the symbiosis effects on the rhizosphere microbial and enzyme activities. In this study, the rhizospheric and non-rhizospheric soils were collected from an experimental field planted with two genotypes of tall fescue, either infected (E+) or free of endophyte (E-) after five years. Arginine ammonification rate and the activities of some soil hydrolases were measured. Results showed that endophyte infection enhanced arginine ammonification rates by 2.3-6.9 times. Except for acid phosphomonoesterase, the activities of other soil enzymes were 1.07-4.6 times greater in the E+ rhizosphere than their E-counterparts. This finding implies that the beneficial effects of the symbiosis are partly due to its potential role to enhance nutrient cycling through increasing hydrolytic enzyme activities.