Clohesyomyces symbioticus sp. nov., a fungal endophyte associated with roots of water smartweed (Persicaria amphibia)

A Elizabeth Arnold,Dustin Sandberg

doi:10.35535/pfsyst-2021-0018

Abstract

The widespread aquatic plant Persicaria amphibia (water smartweed, Polygonaceae) occurs in both flooded aquatic habitats and moist terrestrial environments. Its physiological versatility and wide geographic range highlight its resilience to stress and make the species intriguing for the study of fungal endophytes. Endophytes occur within living plant tissues and are known from diverse aquatic, marine, and terrestrial plants, where they often mitigate plant responses to stress. As part of a study evaluating endophyte communities associated with aquatic plants in lentic waters of Arizona, USA, we isolated a distinctive clade of endophytes from healthy, living roots of seasonally inundated P. amphibia, which we describe here on the basis of morphology and evidence from four loci as new species Clohesyomyces symbioticus (Lindgomycetaceae, Pleosporales, Dothideomycetes, Ascomycota). Clohesyomyces has long been considered a monotypic genus comprising the saprobic species C. aquaticus, presently known from submerged wood in freshwater systems in Asia and Australia. Description of Clohesyomyces symbioticus highlights the occurrence of endophytism in this genus and expands its geographic scope to the western hemisphere.

Highlights

Aquatic plants that persist under non-inundated conditions often have physiology and root traits that may attract distinctive fungal symbionts relative to purely aquatic and purely terrestrial plants (Sandberg et al 2014; Moora et al 2016; Stevens et al 2018)
It is primarily aquatic, water smartweed (Persicaria amphibia, Poly gonaceae) is an emergent macrophyte that can survive in moist locations or when stranded by receding waters (Mitchell 1968; Costea 2012)
We previously characterized communities of fungal symbionts associated with leaves and roots of P. amphibia in lentic systems in central Arizona, with a special focus on fungal endophytes (Sandberg et al 2014)

Summary

Introduction

Aquatic plants that persist under non-inundated conditions often have physiology and root traits that may attract distinctive fungal symbionts relative to purely aquatic and purely terrestrial plants (Sandberg et al 2014; Moora et al 2016; Stevens et al 2018). It is primarily aquatic, water smartweed (Persicaria amphibia, Poly gonaceae) is an emergent macrophyte that can survive in moist locations or when stranded by receding waters (Mitchell 1968; Costea 2012). Plant and Fungal Systematics 66(2): 201–210, 2021 highlights the large geographic range of Clohesyomy ces, including southwestern North America, and expands the ecological scope of the genus by including endophytism in living roots

Materials and methods

Results

Discussion