Hemoglobins in the legume–rhizobium symbiosis

Larrainzar Rodríguez, Estíbaliz; Villar, Irene; Rubio, María Carmen; Pérez Rontomé, Carmen; Huertas, Raúl

Publication:
Hemoglobins in the legume–rhizobium symbiosis

dc.contributor.author	Larrainzar Rodríguez, Estíbaliz
dc.contributor.author	Villar, Irene
dc.contributor.author	Rubio, María Carmen
dc.contributor.author	Pérez Rontomé, Carmen
dc.contributor.author	Huertas, Raúl
dc.contributor.department	Institute for Multidisciplinary Research in Applied Biology - IMAB	en
dc.date.accessioned	2021-02-19T08:12:08Z
dc.date.available	2021-05-13T23:00:12Z
dc.date.issued	2020
dc.description.abstract	Legume nodules have two types of hemoglobins: symbiotic or leghemoglobins (Lbs) and nonsymbiotic or phytoglobins (Glbs). The latter are categorized into three phylogenetic classes differing in heme coordination and O2 affinity. This review is focused on the roles of Lbs and Glbs in the symbiosis of rhizobia with crop legumes and the model legumes for indeterminate (Medicago truncatula) and determinate (Lotus japonicus) nodulation. Only two hemoglobin functions are well established in nodules: Lbs deliver O2 to the bacteroids and act as O2 buffers, preventing nitrogenase inactivation; and Glb1-1 modulates nitric oxide concentration during symbiosis, from the early stage, avoiding the plant’s defense response, to nodule senescence. Here, we critically examine early and recent results, update and correct the information on Lbs and Glbs with the latest genome versions, provide novel expression data and identify targets for future research. Crucial unresolved questions include the expression of multiple Lbs in nodules, their presence in the nuclei and in uninfected nodule cells, and, intriguingly, their expression in nonsymbiotic tissues. RNA-sequencing data analysis shows that Lbs are expressed as early as a few hours after inoculation and that their mRNAs are also detectable in roots and pods, which clearly suggests that these heme proteins play additional roles unrelated to nitrogen fixation. Likewise, issues awaiting investigation are the functions of other Glbs in nodules, the spatiotemporal expression profiles of Lbs and Glbs at the mRNA and protein levels, and the molecular mechanisms underlying their regulation during nodule development and in response to stress and hormones.	en
dc.description.sponsorship	This work has been funded by the Spanish Ministry of Science and Innovation-European Regional Development Fund (grants AGL2017-85775-R and RTI2018-094623-B-C22) and by Government of Aragón, Spain (group A09_17R). EL is a Ramón y Cajal fellow (RYC2018-023867-I) and IV is a Formación de Personal Investigador fellow (BES-2015-073059).	en
dc.embargo.lift	2021-05-13
dc.embargo.terms	2021-05-13
dc.format.extent	32 p.
dc.format.mimetype	application/pdf	en
dc.identifier.doi	10.1111/nph.16673
dc.identifier.issn	1469-8137 (Electronic)
dc.identifier.uri	https://academica-e.unavarra.es/handle/2454/39263
dc.language.iso	eng	en
dc.publisher	Wiley	en
dc.publisher	New Phytologist Trust	en
dc.relation.ispartof	New Phytologist, 2020, 228(2), 472-484	en
dc.relation.projectID	info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/AGL2017-85775-R/ES/	en
dc.relation.publisherversion	https://doi.org/10.1111/nph.16673
dc.rights	© 2020 The Authors. New Phytologist © 2020 New Phytologist Trust	en
dc.rights.accessRights	info:eu-repo/semantics/openAccess
dc.subject	Leghemoglobins	en
dc.subject	Model legumes	en
dc.subject	Nitric oxide	en
dc.subject	Nitrogen ﬁxation	en
dc.subject	Oxygen transport	en
dc.subject	Phytoglobins	en
dc.subject	Rhizobium	en
dc.subject	Symbiosis	en
dc.title	Hemoglobins in the legume–rhizobium symbiosis	en
dc.type	info:eu-repo/semantics/article
dc.type.version	info:eu-repo/semantics/acceptedVersion	en
dc.type.version	Versión aceptada / Onetsi den bertsioa	es
dspace.entity.type	Publication
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relation.isAuthorOfPublication.latestForDiscovery	4c9f12d9-f227-4241-83e9-d27cecd36103