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

Abstract

In this work, 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-1α (tef1) were characterized. Genealogical concordance phylogenetic species recognition (GCPSR) detected a genetically isolated clade 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 separatedmore » by a relatively long genetic distance. Our work highlights that the pleosporalean taxa might represent an underexplored reservoir of root DSEs.« less

Authors:

Yuan, Zhilin  ^[1];

• Search DOE PAGES for author "Yuan, Zhilin"
• Search DOE PAGES for ORCID "0000-0002-5799-8401"

Druzhinina, Irina S.  ^[2];

• Search DOE PAGES for author "Druzhinina, Irina S."
• Search DOE PAGES for ORCID "0000-0003-2821-5268"

Wang, Xinyu ^[3]; Zhang, Xiaoguo ^[3]; Peng, Long  ^[1];

• Search DOE PAGES for author "Peng, Long"
• Search DOE PAGES for ORCID "0000-0002-8345-6278"

Labbé, Jessy  ^[4]

• Search DOE PAGES for author "Labbé, Jessy"
• Search DOE PAGES for ORCID "0000-0003-0368-2054"

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+ Show Author Affiliations

1. Chinese Academy of Forestry, Beijing (China); Chinese Academy of Forestry, Hangzhou (China)
2. Nanjing Agricultural Univ. (China)
3. Chinese Academy of Forestry, Hangzhou (China)
4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Publication Date:

Wed Oct 16 00:00:00 EDT 2019

Research Org.:

Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Biological and Environmental Research (BER); National Natural Science Foundation of China (NSFC); Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP); Coordenaçao de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

OSTI Identifier:

1648877

Alternate Identifier(s):

OSTI ID: 1780043

Grant/Contract Number:  

AC05-00OR22725

Resource Type:

Accepted Manuscript

Journal Name:

Fungal Biology

Additional Journal Information:

Journal Volume: 124; Journal Issue: 5; Conference: 3.International Symposium on Fungal Stress (ISFUS-2019), São José dos Campos, São Paulo (Brazil), 20-23 May 2019; Journal ID: ISSN 1878-6146

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

59 BASIC BIOLOGICAL SCIENCES; Carbon utilization; Dark septate endophytes; Intraspecific polymorphism; Root-fungal mutualism