Know more

Our use of cookies

Cookies are a set of data stored on a user’s device when the user browses a web site. The data is in a file containing an ID number, the name of the server which deposited it and, in some cases, an expiry date. We use cookies to record information about your visit, language of preference, and other parameters on the site in order to optimise your next visit and make the site even more useful to you.

To improve your experience, we use cookies to store certain browsing information and provide secure navigation, and to collect statistics with a view to improve the site’s features. For a complete list of the cookies we use, download “Ghostery”, a free plug-in for browsers which can detect, and, in some cases, block cookies.

Ghostery is available here for free: https://www.ghostery.com/fr/products/

You can also visit the CNIL web site for instructions on how to configure your browser to manage cookie storage on your device.

In the case of third-party advertising cookies, you can also visit the following site: http://www.youronlinechoices.com/fr/controler-ses-cookies/, offered by digital advertising professionals within the European Digital Advertising Alliance (EDAA). From the site, you can deny or accept the cookies used by advertising professionals who are members.

It is also possible to block certain third-party cookies directly via publishers:

Cookie type

Means of blocking

Analytical and performance cookies

Realytics
Google Analytics
Spoteffects
Optimizely

Targeted advertising cookies

DoubleClick
Mediarithmics

The following types of cookies may be used on our websites:

Mandatory cookies

Functional cookies

Social media and advertising cookies

These cookies are needed to ensure the proper functioning of the site and cannot be disabled. They help ensure a secure connection and the basic availability of our website.

These cookies allow us to analyse site use in order to measure and optimise performance. They allow us to store your sign-in information and display the different components of our website in a more coherent way.

These cookies are used by advertising agencies such as Google and by social media sites such as LinkedIn and Facebook. Among other things, they allow pages to be shared on social media, the posting of comments, and the publication (on our site or elsewhere) of ads that reflect your centres of interest.

Our EZPublish content management system (CMS) uses CAS and PHP session cookies and the New Relic cookie for monitoring purposes (IP, response times).

These cookies are deleted at the end of the browsing session (when you log off or close your browser window)

Our EZPublish content management system (CMS) uses the XiTi cookie to measure traffic. Our service provider is AT Internet. This company stores data (IPs, date and time of access, length of the visit and pages viewed) for six months.

Our EZPublish content management system (CMS) does not use this type of cookie.

For more information about the cookies we use, contact INRA’s Data Protection Officer by email at cil-dpo@inra.fr or by post at:

INRA
24, chemin de Borde Rouge –Auzeville – CS52627
31326 Castanet Tolosan CEDEX - France

Dernière mise à jour : Mai 2018

Menu LIPM logo INRAE CNRS

Laboratory of Plant-Microbe Interactions - LIPM

Laboratory of Plant-Microbe Interactions

Research themes - Endosymbiotic infection and nodule development

(I) Regulation and dynamics of rhizobial infection

Fig2b-2

Endosymbiotic root entry takes place in most Fabaceae legume species, via de novo constructed tubular structures, called infection threads that guide rhizobia transcellularly towards the nodule primordia. By using molecular genetics, we have identified key ERF transcription regulators that orchestrate infection thread development and progression in Medicago (Andriankaja et al., 2007; Cerri et al., 2012, 2016, 2017; Liu et al., 2019). We now combine comparative transcriptomics, as well as other molecular and genetic approaches to decipher the genetic pathways they regulate. Our team also largely uses live cell imaging approaches to understand the dynamics of infection thread development and associated cellular signaling. In this context, we have developed a series of fluorescence markers (e.g. calcium sensors and symbiotic protein fusions) and discovered specific cellular remodeling responses and a new symbiotic protein complex contributing to infection thread growth in Medicago (Fournier et al., 2015; Kelner et al., 2018; Liu et al., 2019b). We are now combining various strategies (including cell-type specific molecular and cellular approaches) to understand plant-bacterial cross talk and plant cell reprogramming for bacterial infection. Finally, our work has also shown that the host plant promotes the creation of symplastic cellular communications to coordinate nodule development and bacterial colonization (Gaudioso-Pedraza et al., 2018), a process that we are currently studying in a broader context of other root symbioses.

Contact:

Joëlle Fournier (CR CNRS) & Fernanda de Carvalho-Niebel (DR CNRS)

Collaborations:

International: A. Becker (SYNMIKRO, Marburg); E. Larrainzar (University of Navarra, Spain); M. Marín & M. Parniske (LMU, Munich); J. Murray (JIC, UK; Institute of Plant Physiology & Ecology, CAS, Shanghai, China); Y. Benitez-Alfonso (University of Leeds, UK). National: F. Cartieaux & Sergio Svistoonoff (LSTM, Montpellier); P. Frendo & E. Boncompagni (ISA, Sophia-Antipolis); Local: R. Peyraud (iMEAN, Toulouse); N. Frei-Dit-Frey, P-M. Delaux & E. Jamet (LRSV, Toulouse); D. Capela (LIPM, Toulouse).

Funding:

ANR-DFG PRCI Live Switch (2020-2024), INRAE-SPE CREPE (2020-2023); FRAIB-AO-CROSS (2019-2021); ANR-DFG PRCI COME-IN (2015-2019). 

(II) Master regulators of nodule development

Fig3-2

Nodule development in Medicago involves the mitotic activation of root cells following a precise cell division pattern. This gives rise to a nodule structure composed of an apical meristem, enabling nodule growth throughout its lifetime, followed by successive zones of coordinated bacterial and plant cell differentiation, for creating the appropriate microenvironment for symbiotic nitrogen fixation. We study in the team main regulators of these crucial developmental transitions: (i) meristem formation and (ii) nodule differentiation.  

NF-YA1, a CCAAT-box-binding heterotrimeric transcription factor, has been characterized in the team as a main regulator of nodule development in Medicago (Combier et al., 2006; Laloum et al., 2013; Laloum et al.,, 2014; Laporte et al., 2014; Baudin et al., 2015). Besides contributing to early signalling and infection, a nodule fate-map analysis revealed the crucial importance of NF-YA1 for the regulation of nodule meristem formation (Xiao et al., 2014). In order to understand the mode of action of NF-YA1 we are currently identifying and characterising NF-YA1 target genes (Shrestha et al., 2020) as well as protein and epigenetic components of NF-YA1-associated regulatory mechanisms.

By the development of laser capture microdissection (LCM)-RNAseq approaches, the team  generated valuable resources for the scientific community (Jardinaud et al., 2016; Roux et al., 2018), as the first nodule zone-specific plant and rhizobium transcriptome (Roux et al., 2014; https://iant.toulouse.inra.fr/symbimics). This and previous studies enabled to identify key plant regulators of nodule differentiation, including EFD, a crucial ERF transcription factor regulating cytokinin responses via RR4 (Vernié et al., 2008) and new epigenetic mechanisms. Indeed, the team demonstrated a precise spatial-regulation of DNA methylation-associated genes in nodules, the key role of the DNA demethylase DEMETER for nodule differentiation and the preferential clustering of nodule differentiation genes in genomic regions called symbiotic islands, enriched in epigenetic marks (Satgé et al., 2016; Pecrix et al., 2018). The group is currently pursuing the analysis of these important transcription and epigenetic regulators of nodule differentiation.  

Contact:

Pascal Gamas (DR CNRS) & Andreas Niebel (DR CNRS)

Collaborations:

International: F. Ariel (University of Santa Fe, Argentina); F. Blanco & E. Zanetti (University of La Plata, Argentina); E. Larrainzar (University of Navarra, Spain); J. Murray (JIC, UK; Institute of Plant Physiology & Ecology, CAS, Shanghai, China); K. Szczyglowski (University of Western Ontario, Canada); S. Sinharoy (National Institute of Plant Genome Research, New Delhi India). National: M. Benhamed, M. Crespi, F. Frugier (IPS2, Paris-Saclay); P. Frendo (ISA, Sophia-Antipolis). Local: J. Gouzy (LIPM).

Funding:

ANR PioSYM (2019-2024), CNRS-LIA (International associated laboratory) France-Argentina NOCOSYM (2018-2021); ANR EPISYM (2016-2020).