AUTHOR=Arróniz-Crespo María , Bougoure Jeremy , Murphy Daniel V. , Cutler Nick A. , Souza-Egipsy Virginia , Chaput Dominique L. , Jones Davey L. , Ostle Nicholas , Wade Stephen C. , Clode Peta L. , DeLuca Thomas H. 

TITLE=Revealing the transfer pathways of cyanobacterial-fixed N into the boreal forest through the feather-moss microbiome

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1036258

DOI=10.3389/fpls.2022.1036258

ISSN=1664-462X

ABSTRACT=<sec><title>Introduction</title><p>Biological N<sub>2</sub> fixation in feather-mosses is one of the largest inputs of new nitrogen (N) to boreal forest ecosystems; however, revealing the fate of newly fixed N within the bryosphere (i.e. bryophytes and their associated organisms) remains uncertain.</p></sec><sec><title>Methods</title><p>Herein, we combined <sup>15</sup>N tracers, high resolution secondary ion mass-spectrometry (NanoSIMS) and a molecular survey of bacterial, fungal and diazotrophic communities, to determine the origin and transfer pathways of newly fixed N<sub>2</sub> within feather-moss (<italic>Pleurozium schreberi</italic>) and its associated microbiome.</p></sec><sec><title>Results</title><p>NanoSIMS images reveal that newly fixed N<sub>2</sub>, derived from cyanobacteria, is incorporated into moss tissues and associated bacteria, fungi and micro-algae. </p></sec><sec><title>Discussion</title><p>These images demonstrate that previous assumptions that newly fixed N<sub>2</sub> is sequestered into moss tissue and only released by decomposition are not correct. We provide the first empirical evidence of new pathways for N<sub>2</sub> fixed in feather-mosses to enter the boreal forest ecosystem (i.e. through its microbiome) and discuss the implications for wider ecosystem function.</p></sec>