Prof. Nir Ohad

Molecular Biology Ecology of Plants
Faculty of Life Sciences
ביולוגיה מול.ואקול.צמחים סגל אקדמי בכיר
Prof. Nir Ohad
Phone: 03-6407641
Another phone: 03-6407642
Fax: 03-6407642
Office: Britannia-Porter, 406


Prof. Nir Ohad received his B.Sc. in Biology and Earth sciences and his M.Sc. and Ph.D. in Genetics from Hebrew University.  Since 1998, Prof. Ohad has been a member of The School of Plant Sciences and Food Security at Tel-Aviv University.

 Prof. Ohad is studying the role of DNA and Histone methylation as part of epigenetic regulation during plant reproduction and development. His findings were published in leading scientific journals. He is also an author and editor of the Book, “Epigenetics Memory and Control in Plants”. Prof. Ohad together with his colleague Prof. Yalosvky were among the first to adopt the Bimolecular fluorescence complementation assay (BiFC), to study protein-protein interactions in plants. Prof. Ohad teaches introductory class on plant biology as well as advanced classes on epigenetics and genetics of plant reproduction and development.


The Manna Center Program for Food safty and Security (

Prof. Nir Ohad was appointed on 2014 as the head of The Manna Center Program for Food Safety and Security (MCPFSS) at Tel Aviv University.

The Manna Center Program was established to realize Tel Aviv University’s (TAU’s) vision of leveraging its expertise as a leader in scientific and technological innovation toward solving some of the most pressing issues affecting both the local and global needs for sufficient and nutritious food. In view of the expected need to feed over 10 billion by 2050, we will need to ensure a secure supply of nutritional and healthy food in a sustainable manner. Long-term solutions require advances in the biological sciences and agriculture, as well as a top-to-bottom re-evaluation of food policies as they relates to economic, law and business practices. Interdisciplinary and international cooperation is essential for successfully tackling these complex issues.

The Manna Center Program operates to achieve the above goals, employing Research, Education and Outreach programs. To this end, the Program brings together scholars and scientists from TAU and around the world, to prepare the next generation of scientists and policymakers to guide global food security issues in the years to come.



Period Degree Institute Faculty/Department
1992-1997 Post-Doctoral Fellow University of California at Berkeley Department of Plant Biology
1997-1992 Ph.D. Hebrew University Molecular Biology & Genetics
1985-1987 M.Sc. Hebrew University Molecular Biology & Genetics
1982-1985 B.Sc. Hebrew University Biology & Earth Sciences


Academic Appointments and Awards

Year Award/Appointment
1993 EMBO Postdoctoral Long-term Fellowship
1994 Human Frontier Science Program (HFSP) Postdoctoral Fellowship
1998-present Faculty Member; Department of Molecular Biology & Ecology of Plants, Tel Aviv University
Summer 2006 Visiting Professors at NYBG, NY USA. Pfizer Plant Research Laboratory
2010-2014 External Research Fellow at the Freiburg Institute for Advanced Studies(FRIAS), Germany
2014 TAU Rector Awarded for Outstanding teacher
2014-present Head of The Manna Center Program for Food Safety and Security, Tel-Aviv University

Research Interests

Prof. Ohad research aimed at understanding the role of epigenetic mechanisms, including Histone and DNA methylation in regulating plant reproduction and development. To this end we are using the model organisms Arabidopsis as a representative of flowering plants and the moss Physcomitrella patens, a representative of early terrestrial plants, to understand how such mechanisms function and how they have evolved during land plant evolution. 


Specific topics:  Elucidate the mechanism and function of histone and DNA methylation. We study the mechanisms allowing for the onset of de-Novo methylation, maintenance, and de-methylation and the way they affect plant development, and response to the environment, using genetic, molecular, biochemical and genomic tools.

Selected Publications

Eyal Zinger, Ariel Gueijman, Uri Obolski, Yoav Ram, Eliya Ruby, Mor Binder, Nivi Yechieli, Nir Ohad*, Lilach Hadany*, The plant and the ant: less fit Lamium plants produce more dispersible seeds. Scientific Reports. 2019, 9: 6299 


Rafael Yaari, Aviva Katz, Katherine Domb, Keith D. Harris, Assaf Zemach*, N. Ohad*. RdDM-independent de novo and heterochromatin 1 DNA methylation by plant CMT and DNMT3 orthologs. Nature Communication. Nat Commun. 2019; 10: 1613


Oliva M, Butenko Y, Hsieh TF, Hakim O, Katz A, Smorodinsky NI, Michaeli D, Fischer RL, Ohad N. FIE, a nuclear PRC2 protein, forms cytoplasmic complexes in Arabidopsis thaliana. J Exp Bot. 2016, 67(21):6111-6123.


I. Pereman, A. Mosquna, A. Katz, G. Wiedemann, D. Lang, E. L. Decker, Y. Tamada, T. Ishikawa, T. Nishiyama, M. Hasebe, R. Reski and N. Ohad. The Polycomb group protein CLF emerges as a specific tri-methylase of H3K27 regulating gene expression and development in Physcomitrella patens. Biochimica et Biophysica Acta (BBA) - Gene Regulatory Mechanisms  Vol. 1859 (7), 2016, (pp 860-870) 


N.A. Horst, A. Katz, I. Pereman, E.L. Decker, N. Ohad* and R. Reski*. Expression of a single homeobox gene induces phase transition and asexual reproduction in moss. Nature plants 2016,


R. Yaari, C. N.-Malka,G. Wiedemann, N. A. Gershovitz , R. Reski, A. Katz and

N. Ohad.  DNA METHYLTRANSFERASE 1 is involved in mCG and mCCG DNA methylation and is essential for sporophyte development in Physcomitrella patens. Plant Molecular Biology Vol. 88. (5), 2015, (pp 387-400).


C. N. Malka, R. Yaari, R. Itzhak, A. Mosquna, N. Aurbach, A. Katz and N. Ohad.

A single CMT methyltransferase homolog is involved in CHG DNA methylation and development of Physcomitrella patens. Plant Molecular Biology Vol. 84. (6), 2014, (pp 719-735).


Y. Butenko and N. Ohad.  Polycomb-group mediated epigenetic mechanisms through plant evolution. Biochimica et Biophysica Acta. Vol. 1809 (8), 2011 (pp. 395–406).


A. Mosquna, A. Katz, E. L. Decker, S. A Rensing,R. Reski and N. Ohad .Regulation of stem cell maintenance by the Polycomb protein FIE has been conserved during land plant evolution. Development Vol. 136(14) 2009 (pp. 2433-2444).


P. Jullien, A. Mosquna, M. Ingouff, T. Sakata, N. Ohad and F. Berger. Retinoblastoma and its binding partner MSI1 Control imprinting in Arabidopsis. PLoS Biol. Vol. 8(6), 2008 (pp. 1693-1705)


N. Ohad, K. Shichrur and S. Yalovsky.  The analysis of protein-protein interactions in plants by Bimolecular Fluorescence Complementation (BiFC). Plant Physiol, Vol. 145, 2007 (pp. 1090–1099).


N. Ohad. Plant Development: Parental conflict overcome. Nature Vol. 447, 2007 (pp. 275-276). 


K. Aviezer-Hagai, J. Skovorodnikova, M. Galigniana, O. Farchi-Pisanty, E. Maayan, S. Bocovza, Y. Efrat, P. Doring, N. Ohad andA. Breiman.Arabidopsis immunophilins ROF1 (AtFKBP62) and ROF2 (AtFKBP65) exhibit tissue specificity, are heat-stress induced, and bind HSP9. Plant Mol. Biol Vol. 63(2), 2007 (pp. 237-55).


P. Jullien, T. Kinoshita, N. Ohad, and F. Berger. Maintenance of DNA methylation during the Arabidopsis life cycle is essential for parental imprinting. Plant Cell. Vol. 18, 2006 (pp. 1360-1372).


P. Jullien, A. Katz, M. Oliva, N. Ohad* and F. Berger*. Polycomb group complexes self-regulate imprinting of the Polycomb group gene MEDEA in Arabidopsis.

Current Biology Vol. 16, 2006, (pp. 486–492).


A. Zemach, Y. Li, M. Oliva, A. Mosquna, H. Ben-Meir, Y. Avivi, N. Ohad, and G. Grafi. Different Domains Control the Localization and Mobility of LIKE HETEROCHROMATIN PROTEIN1 in Arabidopsis Nuclei. Plant Cell. Vol. 18, 2006, (pp. 133-145)


A. Eshel, A. Katz, Y. Waisel, N. Ohad. Roots of tomato respond to mechanical stimulation by induction of touch genes. Plant Biosystems Vol. 139/2, 2005, (pp. 209-213).


K. Bracha-Drori, K. Shichrur, A. Katz, M. Oliva, R. Angelovici, S. Yalovsky and N. Ohad. Detection of protein-protein interactions in plants by YFP fluorescence complementation. The Plant Journal Vol. 40, 2004 (pp. 4).


A. Mosquna, A. Katz, S. Shochat, G. Grafi and N. Ohad. Interaction of FIE a polycomb protein with pRb:possible mechanism regulating endosperm development. Mol Genet Genomics.Vol. 271, 2004 (pp. 651-657).


A. Katz, M. Oliva, A. Mosquna, O. Hakim, and. N. Ohad. FIE and CURLY LEAF polycomb proteins interact in the regulation of homeobox gene expression during sporophyte development. The Plant Journal Vol. 37, 2004 (pp. 707-719).


T-F. Hsieh, O. Hakim, N. Ohad and R. Fischer. From flour to flower: how polycomb group proteins influence multiple aspects of plant development. Trends Plant Sci. Vol. 9, 2003 (pp. 439-445).


R. Yadegari, T. Kinoshita, O. Lotan, G. Cohen, A.Katz, Y. Choi, A. Katz, K. Nakashima, J.J. Harada, R.B. Goldberg, R.L. Fischer, and N. Ohad. Mutations in the FIE and MEA genes that encode interacting polycomb proteins cause parent-of-origin effects on seed development by distinct mechanisms. The Plant Cell, Vol. 12, 2000 (pp. 2367-2382).


T. Kiyosue, N. Ohad, R.Yadegari , M. Hannon,J. Dinneny, D. Wells,A. Katz, L. Margossian, J.J. Harada, R.B. Goldberg,and R.L. Fischer.Control of fertilization-independent endosperm development by the MEDEA polycomb gene in Arabidopsis. Proc. Natl. Acad. Sci. USA, Vol.96, 1999 (pp. 4186-4191).


N. Ohad, R. Yadegari, L. Margossian, M. Hannon, J. J. Harada, R. B. Goldberg, and R.L. Fischer.  Mutation in FIE, a WD polycomb-group gene, allow endosperm development without fertilization.  The Plant Cell, Vol. 11, 1999 (pp. 407-415).


L. Reiser, Z. Modrusan, L. Margossian, A. Samach, N. Ohad, G. Haughn and R.L. Fischer. The BELL1 gene encodes a homeodomain protein involved in pattern formation in the Arabidopsis ovule primordium.  Cell, Vol. 83, 1995 (pp.753-742).


N. Ohad, L. Margossian, Y. Hsu, C. Williams and R. L. Fischer.  A mutation that allows endosperm development without fertilization. Proc. Natl. Acad. Sci. USA, Vol. 93, 1996 (pp.  5319-5324).


N. Ohad and J. Hirschberg.  Mutations in the D1 subunit of photosystem II distinguish between the Quinone and herbicide-binding sites. The Plant Cell. Vol. 4, 1992 (pp. 273 282).


N. Ohad, D. Amir-Shapira, H. Koike, Y. Inoue, I. Ohad, and J. Hirschberg.  Amino acid substitutions in the D1 protein of photosystem II affect QB- stabilization and accelerate turnover of D1.  Z. Naturforsch, Vol. 45C, 1990 (pp. 402-408).


N. Ohad and J. Hirschberg.  A similar structure of the herbicide binding site in photosystem II of plants and cyanobacteria is demonstrated by site-specific mutagenesis of psbA. Photosynthesis Res., Vol. 23, 1990 (pp.  73-79).

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