Fungal root endophytes and host plant growth

Abstract

Fungal root endophytes are ubiquitous plant associates which colonize their host asymptomatically, but the plant-endophyte relationship is not well understood. The purpose of this study was to determine plant growth response to fungal root endophyte inoculation, using a meta-analysis, and to endophytic metabolites, using experimental methods. Overall, results from the meta-analysis indicate that plant response seems to be neutral to slightly positive, with a limited number of studies demonstrating very high growth responses. The identity of the plant host and endophyte species, and the use of carbon or organic nitrogen were among the most important factors explaining the variability in these data. Plant response to endophytic metabolites was similar to evidence from the meta-analysis; metabolites from most endophytes had no effect under these experimental conditions but some, particularly metabolites from Phialocephala sphaeroides , induced a significant growth increase.