Heribert Hirt

  Professor, Bioscience                                                                                                                  Director, Center for Desert Agriculture

  Office Location: Ibn Al Haytham (Building 2) · Level 3 · Room 3235
  Email: heribert.hirt@kaust.edu.sa
  Faculty lab website: http://www.heribert-hirt.info


Research Keywords
Plant Chromatin Biology, Signal Transduction, Plant Microbe Interaction, Rhizosphere Microbes, MAP Kinase


Research Interests
Prof. Hirt’s research is focused on how plants can survive under abiotic or biotic stress conditions. The main interest lies in how protein kinases can reprogram gene expression. At KAUST, Prof. Hirt is establishing two research groups. One research group focuses on how MAP kinases target chromatin to prime stress tolerance at both the genetic and the epigenetic level. The other research group searches for rhizosphere microbes of desert plants and investigates their potential and mechanisms to induce stress tolerance in plants. Although the major part of these two projects is carried out in Arabidopsis, the generated knowledge will be applied to crop plants with the aim to provide sustainable solutions to reestablish agriculture in arid regions or under extreme environmental conditions.

Stress chromatin biology 
So far, plant breeding was mostly based on genetically modifying crop species, but epigenetic approaches for obtaining long term adaptation and transgenerational stress tolerance are emerging concepts that receive increased attention. It is well-known that plants can be primed by biotic and abiotic factors for improved pathogen resistance, stress tolerance and yield and it is conceivable that the priming responses are dependent on long term somatic memory. Although priming has been associated with modifications at both the protein level of signaling factors and histones as well as at the DNA level by methylation, the molecular mechanisms underlying priming of epigenetic stress tolerance are still poorly understood. Using a novel chromatin purification protocol and high resolution mass spectrometry proteomics, we have identified a large number of chromatin proteins that become rapidly phosphorylated by stress-induced protein kinases in Arabidopsis thaliana. In the context of this project, we now aim to unravel the role of the modification of these chromatin factors in priming stress tolerance. We expect that this knowledge will strongly contribute to a new concept in future crop breeding for stress tolerance.     

Desert rhizosphere microbes 
All plants have evolved mechanisms to respond to changing environmental conditions, but the ability of a variety of plants to adapt to extreme stress conditions also depends on the association with specific rhizosphere microbes. Therefore, our project aims are to identify the rhizosphere microbes that are associated with plants growing in extreme heat, drought and salt conditions. Then, we want to identify the molecular mechanisms that enable plants to adapt to extreme environmental conditions induced by the microbial association and finally, use the appropriate rhizosphere partners to enhance plant stress tolerance and help increase crop food production in a sustainable way.


Main Techniques
The techniques used in the laboratory range from standard microbiology and plant biology techniques for cultivation and propagation of microbes and plants to specific techniques in genetics (forward and reverse genetics, mutagenesis and overexpression), molecular biology (cloning, mutagenesis, yeast 2 hybrid, bifluorescent complementation), biochemistry (protein expression, purification, co-immunoprecipitation, kinase assays, Western blotting) as well as transcriptomics and proteomics techniques including their bioinformatic analysis.


Members of the Lab
Feras Lafi: Senior Researcher in microbiology. Feras focuses on the isolation and characterization of rhizosphere microbes from endogenous plants of the Arab Peninsula.
Feras obtained his PhD from the University of Queensland, working on bacterial metagenomics. 

Naganand Rayapuram: Senior Researcher in molecular biology, biochemistry and proteomics. Naganand studies the post-translational modification of chromatin associated proteins in response to stress.
Naganand obtained his PhD form Universite de Strasbourg, (formerly Universite Louis Pasteur) France, working on the biogenesis of c-type cytochromes in plant mitochondria.
 
Maged Saad: Senior Researcher in plant-microbe interaction. Maged works on the molecular mechanism of the communication between plants and rhizosphere microbes. 
Maged obtained his PhD from Faculty of Sciences, Geneva University, Switzerland, working on the role of type three secretion systems (T3SS) proteins in the legume- rhizobium interaction. 

Axel de Zelicourt: Post-doc in molecular biology. Axel focuses on the plant stress physiology and tolerance mechanisms under the influence of beneficial rhizosphere microbes and environmental stresses.
Axel obtained his PhD from Nantes University in 2008 where he studied sunflower resistance mechanism to the root parasitic plants Orobanche cumana.

Ronny Voelz: Post-doc in plant development. Ronny studies the biological functions of particular MAPK targets during stress and development.
Ronny obtained his PhD from the Univ. of Tuebingen, Germany, working on flower and embryo development in Arabidopsis.

Juan Ramirez Prado: Master student in Biosciences. Juan isolates and characterizes rhizosphere microbes from endemic plants of the Arab Peninsula. Juan obtained his B.Sc. at los Andes Univ., Colombia.


Selected Publications
Montillet, J.-L., Leonhardt, N., Mondy, S., Tranchimand, S., Rumeau, D., Boudsocq, M., Garcia, A.V., Douki, T., Bigeard, J., Laurière, C., Chevalier, A., Castresana, C.,  Hirt, H. (2013) An ABA-independent oxylipin pathway controls stomatal closure and immune defense in Arabidopsis. PLoS Biol. (in press).

Schikora A, Garcia AV, Hirt H.(2012) Plants as alternative hosts for Salmonella. Trends Plant Sci. 17:245-9. 

Berriri S, Garcia AV, Frei Dit Frey N, Rozhon W, Pateyron S, Leonhardt N, Montillet JL, Leung J, Hirt H, Colcombet J. (2012) Constitutively Active Mitogen-Activated Protein Kinase Versions Reveal Functions of Arabidopsis MPK4 in Pathogen Defense Signaling. Plant Cell 24, :4281-93.

Pitzschke A, Hirt H.(2010) New insights into an old story: Agrobacterium-induced tumour formation in plants by plant transformation. EMBO J. 29:1021-32.

Pitzschke, A., Djamei, A., Teige, M., Hirt, H. (2009) VIP1 response elements mediate mitogen-activated protein kinase 3-induced stress gene expression. Proc. Natl. Acad. Sci. USA, 106:18414-9.

Djamei, A., Pitzschke, A., Nakagami, H., Rajh, I., and Hirt, H. (2007) Trojan horse strategy in Agrobacterium transformation by abusing MAPK defence signalling. Science, 318, 453-456.