Format

Send to

Choose Destination
BMC Genomics. 2018 Jun 5;19(1):434. doi: 10.1186/s12864-018-4743-5.

Distinctive characters of Nostoc genomes in cyanolichens.

Author information

1
Faculty of Life and Environmental Sciences, University of Iceland, Sturlugata 7, Reykjavík, 101, Iceland. a.gagunashvili@ucl.ac.uk.
2
Faculty of Life and Environmental Sciences, University of Iceland, Sturlugata 7, Reykjavík, 101, Iceland.

Abstract

BACKGROUND:

Cyanobacteria of the genus Nostoc are capable of forming symbioses with a wide range of organism, including a diverse assemblage of cyanolichens. Only certain lineages of Nostoc appear to be able to form a close, stable symbiosis, raising the question whether symbiotic competence is determined by specific sets of genes and functionalities.

RESULTS:

We present the complete genome sequencing, annotation and analysis of two lichen Nostoc strains. Comparison with other Nostoc genomes allowed identification of genes potentially involved in symbioses with a broad range of partners including lichen mycobionts. The presence of additional genes necessary for symbiotic competence is likely reflected in larger genome sizes of symbiotic Nostoc strains. Some of the identified genes are presumably involved in the initial recognition and establishment of the symbiotic association, while others may confer advantage to cyanobionts during cohabitation with a mycobiont in the lichen symbiosis.

CONCLUSIONS:

Our study presents the first genome sequencing and genome-scale analysis of lichen-associated Nostoc strains. These data provide insight into the molecular nature of the cyanolichen symbiosis and pinpoint candidate genes for further studies aimed at deciphering the genetic mechanisms behind the symbiotic competence of Nostoc. Since many phylogenetic studies have shown that Nostoc is a polyphyletic group that includes several lineages, this work also provides an improved molecular basis for demarcation of a Nostoc clade with symbiotic competence.

KEYWORDS:

Cyanobacteria; Lichen; Nostoc; Symbiosis; Symbiotic competence

PMID:
29866043
PMCID:
PMC5987646
DOI:
10.1186/s12864-018-4743-5
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for BioMed Central Icon for PubMed Central
Loading ...
Support Center