BIBLIOS

Document type
Journal articles

Document subtype
Full paper

Title
The impact of salinity on the symbiosis between Casuarina glauca Sieb. ex Spreng. and N2-fixing Frankia bacteria based on the analysis of Nitrogen and Carbon metabolism

Participants in the publication
Nuno Duro (Author)
Paula Batista-Santos (Author)
Mário da Costa (Author)
Rodrigo Maia (Author)
Isabel V. Castro (Author)
Margarida Ramos (Author)
Dep. Biologia Vegetal
cE3c
José C. Ramalho (Author)
Katharina Pawlowski (Author)
Cristina Máguas (Author)
Dep. Biologia Vegetal
cE3c
Ana Ribeiro-Barros (Author)

Summary
Background and aims\nCasuarina glauca is an actinorhizal plant that establishes root-nodule symbiosis with N2-fixing bacteria of the genus Frankia. This plant is highly recalcitrant to extreme environmental conditions such as salinity and drought. The aim of this study was to evaluate the impact of salt stress on the symbiotic relationship between C. glauca and Frankia Thr, focusing on N and C metabolism.\n\nMethods\nSymbiotic and non-symbiotic plants were exposed to 0, 200, 400 and 600 mM NaCl. The following analyses were performed: stable carbon (δ13C) and nitrogen (δ15N) isotope signature; nitrogenase activity in nodules (acetylene reduction assay); and gene expression of a set of genes involved in nodule infection and N/C metabolism (qRT-PCR). Data were analysed using two-way ANOVA.\n\nResults\nSalt stress induced an enrichment in δ13C and δ15N, reflecting a negative impact of salt in the relative water content and N2 fixation, respectively. Furthermore, nitrogenase activity in nodules was insignificant already at 200 mM NaCl, consistent with the expression patterns of nifH as well as of plant genes involved in nodule induction and metabolism.\n\nConclusions\nThe ability of C. glauca to thrive under highly saline environments is not dependent on the symbiosis with Frankia.


Where published
Plant and Soil

Publication Identifiers
ISSN - 0032-079X

Publisher
Springer Nature



Document Identifiers
URL - http://dx.doi.org/10.1007/s11104-015-2666-3
DOI - https://doi.org/10.1007/s11104-015-2666-3

Rankings
SCOPUS Q1 (2016) - 1.295 - Plant Science
SCIMAGO Q1 (2016) - 1.295 - Plant Science

Keywords
Casuarina glauca Frankia Actinorhizal nodules Salt stress