Nitric oxide (NO): a key player in the senescence of Medicago truncatula root nodules
- Others:
- Unité mixte de recherche interactions plantes-microorganismes ; Institut National de la Recherche Agronomique (INRA)-Université Toulouse III - Paul Sabatier (UT3) ; Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)
- UMR 2594 ; Centre National de la Recherche Scientifique (CNRS)
- Institut Sophia Agrobiotech (ISA) ; Institut National de la Recherche Agronomique (INRA)-Université Nice Sophia Antipolis (1965 - 2019) (UNS) ; COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)
- Agence Nationale de la Recherche [BLAN 071_184783]; Laboratoired' Excellence (LABEX) TULIP [ANR-10-LABX-41]; Contrat Jeune Scientifique INRA; National Institute for Applied Sciences (INSA-Toulouse, France)
Description
Nitric oxide (NO) is a signalling and defence molecule involved in diverse plant developmental processes, as well as in the plant response to pathogens. NO has also been detected at different steps of the symbiosis between legumes and rhizobia. NO is required for an optimal establishment of the Medicago truncatulaSinorhizobium meliloti symbiotic interaction, but little is known about the role of NO in mature nodules. Here, we investigate the role of NO in the late steps of symbiosis. Genetic and pharmacological approaches were conducted to modulate the NO level inside root nodules, and their effects on nitrogen fixation and root nodule senescence were monitored. An increase in endogenous NO levels led to a decrease in nitrogen fixation and early nodule senescence, characterized by cytological modifications of the nodule structure and the early expression of a specific senescence marker. By contrast, a decrease in NO levels led to a delay in nodule senescence. Together, our results strongly suggest that NO is a signal in developmental as well as stress-induced nodule senescence. In addition, this work demonstrates the pivotal role of the bacterial NO detoxification response in the prevention of early nodule senescence, and hence the maintenance of efficient symbiosis.
Abstract
International audience
Additional details
- URL
- https://hal.inrae.fr/hal-02650936
- URN
- urn:oai:HAL:hal-02650936v1
- Origin repository
- UNICA