Insight into a highly polymorphic endophyte isolated from the roots of the halophytic seepweed Suaeda salsa: Laburnicola rhizohalophila sp. nov. (Didymosphaeriaceae, Pleosporales)

Author(s)

Yuan, Zhilin ^{[1, 2]} ; Druzhinina, Irina S. ^[3] ; Wang, Xinyu ^[2] ; Zhang, Xiaoguo ^[2] ; Peng, Long ^{[1, 2, 4]} ; Labbe, Jessy ^[5]

Affiliation

^[1] Chinese Acad Forestry, State Key Lab Tree Genet & Breeding, Beijing - Peoples R China

^[2] Chinese Acad Forestry, Inst Subtrop Forestry, Hangzhou - Peoples R China

^[3] Nanjing Agr Univ, Coll Resources & Environm Sci, Fungal Genom Grp, Nanjing - Peoples R China

^[4] Labbe, Jessy, Oak Ridge Natl Lab, Biosci Div, Oak Ridge, TN USA.Yuan, Zhilin, Chinese Acad Forestry, State Key Lab Tree Genet & Breeding, Beijing - Peoples R China

^[5] Oak Ridge Natl Lab, Biosci Div, Oak Ridge, TN - USA

• Document type: Journal article
• Source: FUNGAL BIOLOGY; v. 124, n. 5, p. 327-337, MAY 2020.
• Web of Science Citations: 1

Abstract

We surveyed root endophytic fungi of the coastal halophyte Suaeda salsa and detected a population of a novel species that we described here as Laburnicola rhizohalophila sp. nov. No sexual sporulating structure was observed. Instead, it produced a large amount of thalloconidia, 0-1 transverse septa, hyaline to darkly pigmented, often peanut-shaped and sometimes dumbbell-shaped, both ends enlarged with numerous oil droplets inside the hyphal cells. Surprisingly, a high degree of phenotypic and physiological intraspecific variation (e.g., salinity tolerance, growth under different carbon:nitrogen ratios, and carbon utilization pattern) was recorded. The inoculation test indicated that the isolates could successfully infect host roots and form microsclerotia-like structures in cortical cells, a typical trait of dark septate endophytes (DSEs). Furthermore, most isolates were shown to promote host seedling growth. To evaluate conspecificity and infer its phylogenetic affinity, multiloci data including nuclear rRNA loci (ITS1 and 2, partial 28S), partial RNA Polymerase II second-largest subunit (rpb2), and partial translation elongation factor-1 alpha (tef1) were characterized. Genealogical concordance phylogenetic species recognition (GCPSR) detected a genetically isolated Glade of L rhizohalophila within the Pleosporales in the Didymosphaeriaceae. Maximum likelihood phylogenetic reconstruction revealed that the endophytic fungus was genetically close to Laburnicola dactylidis but separated by a relatively long genetic distance. Our work highlights that the pleosporalean taxa might represent an underexplored reservoir of root DSEs. (C) 2019 British Mycological Society. Published by Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 18/20571-6 - International Symposium on Fungal Stress - ISFUS
• Grantee: Drauzio Eduardo Naretto Rangel
• Support Opportunities: Organization Grants - Scientific Meeting