Prof. Nir Ohad

ביולוגיה מול.ואקול.צמחים סגל אקדמי בכיר
Prof. Nir Ohad
Phone: 03-6407641
Another phone: 03-6407642
External phone: 03-6407641
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.




Post-Doctoral Fellow; Department of Plant Biology, University of California at Berkeley

1997-1992 Ph.D.; Molecular Biology & Genetics, Hebrew University
1985-1987 M.Sc.; Molecular Biology & Genetics, Hebrew University
1982-1985 B.Sc; Biology & Earth Sciences, Hebrew Univesity


Academic Appointments:

1998-present Faculty Member; Department of Molecular Biology & Ecology of Plants, Tel Aviv University
2014-present Head of The Manna Center Program for Food Safety and Security, Tel-Aviv University


Research Interests

Our research is 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.  


Recent Publications

E. Zinger, A. Gueijman, U. Obolski, Y. Ram, E. Ruby, M. Binder, N. Yechieli, N. Ohad*, L. Hadany*, The plant and the ant: less fit Lamium plants produce more dispersible seeds. (Pending after revisions, 2019)


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. (In press 2019).


Avni R, Nave M, Barad O, Baruch K, Twardziok SO, Gundlach H, Hale I, Mascher M, Spannagl M, Wiebe K, Jordan KW, Golan G, Deek J, Ben-Zvi B, Ben-Zvi G, Himmelbach A, MacLachlan RP, Sharpe AG, Fritz A, Ben-David R, Budak H, Fahima T, Korol A, Faris JD, Hernandez A, Mikel MA, Levy AA, Steffenson B, Maccaferri M, Tuberosa R, Cattivelli L, Faccioli P, Ceriotti A, Kashkush K, Pourkheirandish M, Komatsuda T, Eilam T, Sela H, Sharon A, Ohad N, Chamovitz DA, Mayer KFX, Stein N, Ronen G, Peleg Z, Pozniak CJ, Akhunov ED, Distelfeld A.

Wild emmer genome architecture and diversity elucidate wheat evolution and domestication. Science. 2017, 7; 357(6346):93-97.


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.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 andN. 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).


A. Yano, Y. Kodama, A. Koike, T. Shinya, H. Kim, M. Matsumoto, S. Ogita, Y. Wada, N. Ohad and H. Sano.Interaction between Methyl CpG-Binding protein and Ran GTPase during Cell Division in Tobacco Cultured Cells. Annals of Botany Vol. 98, 2006 (pp. 1179- 1187).


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 andN. 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).


E. Marco, N. Ohad, R, Schwartz, J. Lieman-Hurwitz, C. Gabay, and A. Kaplan.

High COconcentration alleviates the block in photosynthetic electron transport in an NDHB inactivated mutant of Synechococcus sp. PCC 7942. Plant. Physiol., Vol. 101, 1993 (pp. 1047-1053).


J. Cao, N. Ohad, J. Hirschberg, J. Xiong, and Govindjee.Binding affinity of bicarbonate and formate in herbicide-resistant D1 mutants of Synechococcus PCC7942. Photosynth. Res., Vol. 34, 1992 (pp. 397-408).


H.M. Gleiter, N. Ohad, H. Koike, J. Hirschberg, G. Renger, Y. Inoue. Thermoluminescence and flash-induced oxygen yield in herbicide resistant mutants of the D1 protein in Synechococcus PCC7942.Biochim. Biophys. Acta., Vol.1440, 1992 (pp. 135-143).


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).


H.M. Gleiter, N. Ohad, J. Hirschberg, R. Fromme, G. Renger, H. Koike, and Y. Inoue.An application of thermoluminescence to herbicide studies.Z. Naturforsch, Vol. 45C, 1990 (pp. 353-358).


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).


Horovitz, N. Ohad, and J. Hirschberg.Predicted effects on herbicide binding of amino acid substitutions in the D1 protein of photosystem II. FEBS Lett., Vol. 234, 1989 (pp. 161-164).


J. Hirschberg, N. Ohad, I. Pecker, and A. Rahat.Isolation and characterization of herbicide resistant mutants in the cyanobacterium Synechococcus R2. Z. Naturforsch, Vol. 42c, 1987 (pp. 758-761).

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