פרופ' ניר אוהד

סגל אקדמי בכיר בביה"ס למדעי הצמח ואבטחת מזון

ביה"ס למדעי הצמח ואבטחת מזון סגל אקדמי בכיר

דואר אלקטרוני: niro@tauex.tau.ac.il

טלפון פנימי: 03-6407641

טלפון נוסף: 03-6407642

פקס: 03-6407642

לפרופיל האישי שלי במערכת CRIS

אתר אישי

משרד: בריטניה, 406

Biography

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 (https://foodsecurity.tau.ac.il).

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.

CV

Education

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
2024	Chair of the TAU/TiET Food Security Center of Excellence at TiET, Patiala, India

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

Joanna Rojek* and Nir Ohad*. The phenomenon of autonomous endosperm in sexual and apomictic plants. Journal of Experimental Botany 74, (15) ,4324–4348(2023).

Ofir Griess, Aviva Katz, Katherine Domb, Keith D. Harris, Karina G. Heskiau, Nir Ohad*, and Assaf Zemach*. Knockout of DDM1 in Physcomitrella patens disrupts DNA methylation with a minute effect on transposon regulation and development. Plos one 18 (3), e0279688,( 2023).

Nguyen, Dat; Trac, Quang Thinh; Nguyen, Ha-Nam; Ohad, Nir; Pawitan, Yudi; Vu, Trung Nghia. Circall: fast and accurate methodology for discovery of circular RNAs from paired-end RNA-sequencing data. BMC Bioinformatics 22, 495 (2021)

Katherine Domba, Aviva Katz, Keith D. Harris, Rafael Yaari, Efrat Kaisler, Vu H. Nguyen, Uyen V. T. Hong, Ofir Griess, Karina G. Heskiaua, Nir Ohad*, and Assaf Zemach*. DNA methylation mutants in Physcomitrella patens elucidate individual roles of CG and non-CG methylation in genome regulation. PNAS 2020 117, 33700-33710

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).