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Institut Sophia Agrobiotech

UMR INRA - Univ. Nice Sophia Antipolis - Cnrs

http://www.paca.inra.fr/institut-sophia-agrobiotech_eng/

KELLER Harald

DR Inra - Senior Scientist

KELLER Harald
© inra
Sensitivity of Arabidopsis to oomycetes

Education

2007

1987-1990 ........

1986-1987

 

Research Supervisor Certificate [Habilitation], University of Nice-Sophia Antipolis.

Ph. D. in Life Sciences [Doktor rer. nat.] of the University of Cologne (Germany). Specialities Biochemistry, Genetics, and Chemistry

Master in Biology[Diplom Biologie] of the University of Cologne (Germany). Specialities Botany, Genetics, and Biochemistry.

Current and previous postions

Since 2006

1999-2006

Senior Scientist [Directeur de Recherche de 2e classe] at INRA.

Junior Scientist [Chargé de Recherche de 1e classe] at INRA Antibes and Sophia Antipolis

1998-1999

Contractual researcher at INRA, Antibes: Crown gall disease of rose trees.

1996-1998

Contractual researcher at INRA, Antibes: Generation and characterzation of transgenic tobacco expressing elicitin genes under the control of a pathogen-inducible promoter.

1994-1996

Post-doc at INRA, Antibes: Defense mechanisms of tobacco induced by elicitins and a phytopathogenic fungus.

1992-1993

Deutsche Forschungsgemeinschaft (DFG) Post-doc at INRA, Antibes: Molecular analysis of systemic acquired resistance in tobacco.

1990-1991

Post-doc at the Max-Planck-Institut für Züchtungsforschung, Cologne, Germany: Functional analysis of an inducible parsley gene (eli5).

1987-1990

Ph. D. thesis at the Max-Planck-Institut für Züchtungsforschung, Cologne: Identification of phenylpropanoid derivatives accumulating in potato during the interaction withPhytophthora infestans.

Main scientific focus

My scientific interest is to identify the molecular mechanisms that underly plant susceptibility to phytopathogenic oomycetes. The laboratory conducts research in the fields of functional genomics, genetics, biochemistry, and molecular and cell biology. The studies focus on two biological systems involving the model plantArabidopsis thalianaas a host, and the oomycete pathogens:

  • Hyaloperonospora arabidopsidis, an obligatory biotrophic oomycete causing mildew disease on leaves. This pathogen is specialised on its host plant Arabidopsis.
  • Phytophthora parasitica, a hemi-biotrophic oomycete, which attacks the roots of Arabidopsis. This pathogen is polyphagous. It initiates infection through a biotrophic phase and subsequently triggers plant cell death.

We perform functional analysis of genes of A. thaliana whose expression levels affect the interaction with H. arabidopsidis. We identified two genes encoding "leucine-rich repeat receptor-like kinases" (LRR-RLKs), a gene encoding a putative negative regulator of cell death, a gene encoding a microtubule-associated protein involved in mitosis, and two genes encoding transferases, an UDP-glucosyltransferase and a methyltransferase involved in the synthesis of monolignols (COMT1).

The model pathosystem between A. thaliana and Phytophthora parasitica was established in our laboratory. This is the first pathosystem involving the model plant and a hemibiotrophic oomycete root pathogen. The compatible interaction is characterized by a prolonged biotrophic phase, which is essential for the life cycle of P. parasitica, but difficult to observe during infection of natural hosts, such as tomato. To describe the transcriptome of infected roots at different stages, from penetration to the outbreak of necrotrophy, we performed extensive µ-array analyses, and initiated the functional analysis of selected candidate genes.

Research projects

  • National Research Agency (ANR) projects: ANR Génoplante AFINDIS  2006-2008, and ANR Génomique SCRIPS 2009-2012. The aim of theses projects was identifying common host targets for three unrelated pathogens (oomycetes, the nematode Meloidogyne incognita, and the bacterium Ralstonia solanacearum.)
  • Valorisation (Génoplante Valor, 2011-2013). An ongoing project aims at showing that the inactivation of a host gene in tomato by TILLING confers broad-spectrum resistance. The gene to be tilled is the ortholog of an Arabidopsis gene that we identified in the course of the above mentioned projects.
  • The analysis of host targets for oomycete pathogens is integrated in the ANR LabEx “Signalife”.

Teaching

Specialized courses and practical training in the frame of the Master program Biology of Adaptation, Module Interactions between Plants and Bioagressors, University of Nice-Sophia Antipolis (since 2004). Frequent invitations from other French Universities for seminars in the frame of Master courses (Toulouse, Rouen).

Expertises

  • Member of National and International grant evaluation panels (ANR France, DFG Germany, NOW The Netherlands, FWF Austria).
  • Member of National panels for the evaluation of Scientists (CSS France), Research Units, and Institutes (AERES France).
  • President of the Scientific Council of the Labex (Laboratory of Excellence) Signalife.
  • Referee of scientific journals such asPlant Journal, Plant Physiology, Mol. Plant Microbe Interact., etc.
  • Organisation of three workshops in the frame of theFOR666 Annual Meetings on Compatibility Mechanisms(2006, 2009, and 2011 in Sophia Antipolis.
  • Member of the Scientific Council of the conference cycle (every two years)Journées Jean Chevaugeon: Rencontres de Mycologie-Phytopathologie(since 2011).

Laboratory members

  • Agnès Attard, Junior Scientist (CR1) INRA
  • Jo-Yanne LeBerre, Engineer (IE) INRA
  • Valerie Allasia, Technician (TR) INRA
  • Master and PhD students

Recent and significant publications/patents

  • Hanemian M, Barlet X, Sorin C, Yadeta K, Keller H, Favery B, Simon R, Thomma B, Hartmann C, Crespi M, Marco Y Trémousaygue D, Deslandes L (2016). Arabidopsis CLAVATA1 and CLAVATA2 receptors contribute to Ralstonia solanacearum pathogenicity through a miR169-dependent pathway. New Phytol., in press.
  • Quentin M, Baurès I, Hoefle C, Caillaud MC, Allasia V, Panabières F, Abad P, Hückelhoven R, Keller H, Favery B (2016).  The Arabidopsis microtubule-associated protein MAP65-3 supports infection by filamentous biotrophic pathogens by down-regulating salicylic acid-dependent defenses.  J Exp Bot., PMID: 26798028.
  • Keller H, Boyer L, Abad P (2016). Disease susceptibiliy in the zig-zag model of host-microbe Interactions: Only a consequence of immune suppression? Mol Plant Pathol., PMID: 26788791
  • Rodiuc N, Barlet X, Hok S, Perfus-Barbeoch L, Allasia V, Engler G, Séassau A, Marteu, N, de Almeida-Engler J, Panabières F, Abad P, Kemmerling B, Marco Y, Favery B, Keller H (2015). Evolutionarily distant pathogens require the Arabidopsis phytosulfokine signalling pathway to establish disease.  Plant Cell Environ., PMID: 26290138.
  • Naessens E, Dubreuil G, Giordanengo P, Baron OL, Minet-Kebdani N, Keller H, et Coustau C (2015). A secreted MIF cytokine enables aphid feeding and represses plant immune responses. Curr. Biol. 25, 1898-1903.
  • Hok S, Allasia V, Andrio E, Naessens E, Ribes E, Panabières F, Attard A, Clément M, Barlet X, Marco Y, Grill E, Eichmann R, Weis C, Hückelhoven R, Ammon A, Ludwig-Müller J, Voll LM, Keller H (2014). The receptor kinase Impaired Oomycete Susceptibility 1 attenuates abscisic acid responses in Arabidopsis. Plant Physiol. 166, 1506-1518.
  • Koch A, Kumar N, Weber L, Keller H, Imani J, Kogel KH (2013). Host-induced gene silencing of cytochrome P450 lanosterol C14α-demethylase-encoding genes confers strong resistance to Fusarium species. Proc. Natl. Acad. Sci. U S A 110, 19324-19329.
  • Mosher S, Seybold H, Rodriguez P, Stahl M, Davies KA, Dayaratne S, Morillo S, Wierzba M, Favery B, Keller H, Tax FE, Kemmerling B (2012). The Tyrosine-sulfated peptide receptors PSKR1 and PSY1R modify Arabidopsis immunity to biotrophic and necrotrophic pathogens in an antagonistic manner. Plant J. 73, 469-482.
  • Rodiuc N, Marco Y, Favery B, et Keller H (2012). Plants resistant to pathogens and methods for production thereof. Brevet WO/2012/017067.
  • Hok S, Danchin EG, Allasia V, Panabières F, Attard A, et Keller H (2011). An Arabidopsis (malectin-like) leucine-rich repeat receptor-like kinase contributes to downy mildew disease. Plant Cell Environ.34, 1944-1957.
  • Attard A, Gourgues M, Callemeyn-Torre N, et Keller H (2010). The immediate activation of defense responses in Arabidopsis roots is not sufficient to prevent Phytophthora parasitica infection. New Phytol.187, 449-460.
  • Hok S, Attard A, et Keller H (2010). Getting the most from the host: how pathogens force plants to cooperate in disease. Mol. Plant-Microbe Interact.23, 1253–1259.
  • Engelhardt S, Lee J, Gäbler Y, Kemmerling B, Haapalainen ML, Li CM, Wei Z, Keller H, Joosten M, Taira S, et Nürnberger T (2009). Separable roles of the Pseudomonas syringae pv.phaseolicola accessory protein HrpZ1 in ion-conducting pore formation and activation of plant immunity.Plant J.57, 706-717.
  • Quentin M, Allasia V, Pegard A, Allais F, Ducrot PH, Favery B, Levis C, Martinet S, Masur C, Ponchet M, Roby D, Schlaich NL, Jouanin L, et Keller H (2009). Imbalanced lignin biosynthesis promotes the sexual reproduction of homothallic oomycete pathogens. PLoS Pathog.5, e1000264.
  • Attard A, Gourgues M, Galiana E, Panabières F, Ponchet M, et Keller H (2008). Strategies of attack and defense in plant-oomycete interactions, accentuated for Phytophthora parasitica Dastur (syn.P. nicotianaeBreda de Haan). J. Plant Physiol.165, 83-94.
  • Hernández-Blanco C, Feng DX, Hu J, Sánchez-Vallet A, Deslandes L, Llorente F, Berrocal-Lobo M, Keller H, Barlet X, Sánchez-Rodríguez C, Anderson LK, Somerville S, Marco Y, et Molina A (2007). Impairment of cellulose synthases required for Arabidopsis secondary cell wall formation enhances disease resistance. Plant Cell 19, 890-903.
  • Racapé J, Belbahri L, Engelhardt S, Lacombe B, Lee J, Lochman J, Marais A, Nicole M, Nürnberger T, Parlange F, Puverel S, et Keller H (2005). Ca2+-dependent lipid binding and membrane integration of PopA, a harpin-like elicitor of the hypersensitive response in tobacco.Mol. Microbiol.58, 1406–1420.
  • Belbahri L, Boucher C, Candresse T, Nicole M, Ricci P, et Keller H (2001). A local accumulation of theRalstonia solanacearumPopA protein in transgenic tobacco renders a compatible plant-pathogen interaction incompatible. Plant J.28, 419-430.
  • Keller H, Pamboukdjian N, Ponchet M, Poupet A, Delon R, Verrier JL, Roby D, et Ricci P (1999). Pathogen-induced elicitin production in transgenic tobacco generates a hypersensitive response and nonspecific disease resistance. Plant Cell11, 223-236.

Email : Harald.Keller@sophia.inra.fr