Glyphosate-based herbicide use affects individual microbial taxa in strawberry endosphere but not the microbial community composition.

Abstract

In a field study, the effects of treatments of glyphosate-based herbicides (GBHs) in soil, alone and in combination with phosphate fertilizer, were examined on the performance and endophytic microbiota of garden strawberry. The root and leaf endophytic microbiota of garden strawberries grown in GBH-treated and untreated soil, with and without phosphate fertilizer were analyzed. Next, bioinformatics analysis on the type of 5-enolpyruvylshikimate-3-phosphate synthase enzyme was conducted to assess the potential sensitivity of strawberry-associated bacteria and fungi to glyphosate, and to compare the results with field observations. GBH treatments altered the abundance and/or frequency of several operational taxonomic units (OTUs), especially those of root-associated fungi and bacteria. These changes were partly related to their sensitivity to glyphosate. Still, GBH treatments did not shape the overall community structure of strawberry microbiota or affect plant performance. Phosphate fertilizer increased the abundance of both glyphosate-resistant and glyphosate-sensitive bacterial OTUs, regardless of the GBH treatments. These findings demonstrate that although the overall community structure of strawberry endophytic microbes is not affected by GBH use, some individual taxa are.