Abstract Detail

Mycology

Healy, Rosanne [1], Arnold, A. Elizabeth [2], Gregory, Bonito [3], Huang, Yu-Ling [4], Lemmond, Benjamin [5], Smith, Matthew [6].

Endophytism in Pezizomycetes: the exception or the rule?

Fungal endophytes are common within healthy plants and lichens around the globe. Several major lineages of non-lichenized Ascomycota contain diverse endophytes, but endophytism is least studied among the Pezizomycetes. Pezizomycetes consists of one order (Pezizales), 23 families, and approximately 2,000 species known as plant pathogens, ectomycorrhizal fungi, and saprobes. However, the endophytic habit has not traditionally been considered an important ecological strategy in Pezizomycetes. Recent culture-based and sequence-based studies have detected diverse Pezizomycetes as endophytes in plants and lichens, but there has been no comprehensive assessment of endophytism in this lineage. We used a phylogenetic framework based on >4000 ITS and 28S rDNA sequences to determine how many Pezizomycetes have been found as endophytes, what lineages contain endophytes, and the main nutritional modes of Pezizomycetes that can act as endophytes. We conservatively delimited >160 OTUs of Pezizomycete endophytes in at least 16 families. These include representatives from 50 genera as well as 13 lineages that could not be assigned to a known genus. Endophytic Pezizomycetes occur in lineages with diverse trophic strategies, including saprobes, plant pathogens, and more rarely, ectomycorrhizal fungi. Endophytes were particularly common among fire-adapted and pyrophilous Pezizomycetes with evidence of endophytism in 12 of those genera. Some endophytic taxa were found on only one or two hosts but many occupy a broad range of hosts. We documented endophytes in two lineages with no previously known endophytes (the ectomycorrhizal genus Otidea and dung saprobe genus Coprotus), as well as one species that was divergent from any taxa represented in GenBank and could not be assigned to a known family. This species is represented by four isolates from angiosperm leaves and lichens in an Alaskan boreal forest and represents a unique lineage nested between the two uniformly ECM families, Tuberaceae and Geomoriaceae. Together these results suggest that endophytism is widespread across the Pezizomycetes and highlights how culture collections – especially when characterized by barcode sequences – can be important for defining the ecology and phylogenetic relationships of fungal lineages in the Pezizomycetes and beyond.

1 - University of Florida, PO Box 110680, Gainesville, FL, 32611, United States
2 - School Of Plant Sciences, 2327 E 7th St, Tucson, AZ, 85719, United States
3 - Helmholtz Centre for Environmental Research, Halle (Saale), Germany
4 - National Museum of Natural Science, Department of Biology, No. 1, Guanqian Road, Taichung, North District, 404, Taiwan
5 - University of Florida, Plant Pathology, PO Box 110680, Gainesville, FL, 32611, United States
6 - Plant Pathology, PO Box 110680, Gainesville, FL, 32611, United States

Keywords:
Endophytes
Pezizales
endolichenic
pyrophilous fungi
Mycology.

Presentation Type: Poster
Session: MYP2, Mycology Posters II
Location: Virtual/Virtual
Date: Tuesday, July 20th, 2021
Time: 5:00 PM(EDT)
Number: MYP2006
Abstract ID:623
Candidate for Awards:None