Prof. Adi Avni
Ph.D.: The Weizmann Institute of Science, Rehovot, Israel, 1990
Phone: (Office) +972-3-640-9840
(Fax) +972-3-6410195
(Lab) +972-3-640-5323
(Home) +972-4-6288957
E-mail: lpavni@post.tau.ac.il
Room#: Britania 628
Member's portrait

Research Interests

 

Plant resistance against disease involves inducible defense mechanisms. One aspect of the plant defense response is the induction of programmed cell death known as hypersensitive response (HR). Our research focuses on understanding the signal transduction pathway by which a fungal protein elicitor induces ethylene biosynthesis, programmed cell death and other plant defense responses. We address this question from several angles: We use genetic approach to isolate the plant gene controlling the plant response to the fungal protein by positional cloning (map based cloning) and microarray (chip technology). We identified of a novel gene family from tomato. These genes show homology to the Ve resistance genes and Cf resistance genes. Using silencing and complementation techniques in intransgenic plants we showed that both genes are capable of binding the fungal effector independently. However, only Eix2 is capable of transmitting the signal to induce the hypersensitive response.

The fungal elicitor EIX (ethylene-inducing xylanase) triggers a defense response via the LeEix2 receptor, in an endocytosis-dependent process. We study the signal transduction pathways that lead to the induction of defense responses using molecular genetic tools.
We demonstrated that the EIX elicitor triggers internalization of the LeEix2 receptor. Treatment with endocytosis, actin or microtubule inhibitors greatly reduced the internalization of LeEix2.

Endocytosis is an essential process by which the eukaryotic cell internalizes exogenous material. Studies in mammalian cells have revealed that endocytosis is a complex molecular process depending on regulated interactions between a variety of proteins and lipids through specific modules. One such module is the Eps15 homology (EH) domain, a conserved modular protein-interaction domain found in several endocytic proteins. We isolated and characterized two plant EH-domain-containing proteins (AtEHD1 and AtEHD2). We show that the two proteins are involved in endocytosis in plant systems and demonstrated that the Arabidopsis EHD proteins function similarly to previously identified mammalian EHDs. Our laboratory study the involvement of the plant EHD proteins in the signaling pathway involved in the induction of plant defense responses. We found that AtEHD2 interact with the cytoplasmic domain of LeEix2 in planta in the BiFC system and its over-expression inhibits the induction of plant defense responses. Additionally, we demonstrated that plant EHD2 binds to LeEix2 and is an important factor in its internalization and in regulation of the induction of defense responses in the case of LeEix2, Cf4 and Cf9, but does not appear to be involved in the FLS2 system. Our results suggest that various endocytosis pathways are involved in the induction of plant defense responses.

Our long-term goals are to generate plants that show high resistance to pathogens using biotechnological tools.

 

 

Selected Publications
  1. Hanania U., Furman-Matarasso N., Ron M. and Avni A.(1999) Isolation of a novel SUMO protein from tomato that suppresses cell death in plants. Plant J. 19:. 533-541
  2. Elbaz M, Avni A and Weil M.(2002) Constitutive caspase-like machinery executes programmed cell death in plant cells Cell Death Diff 9: 726-733
  3. Ron M. and Avni A. (2004)  The receptor for the fungal elicitor Ethylene-Inducing Xylanase is a member of a resistance-like gene family in tomato. Plant Cell 16: 1604-1615

  4. Matarasso N, Schuster S, Avni A. (2005) A novel plant cysteine protease moonlights as a regulator of ACC synthase gene expression. Plant Cell 17:1205-1216

  5. Bar, M. and A. Avni, (2009) EHD2 inhibits ligand-induced endocytosis and signaling of the leucine-rich repeat receptor-like protein LeEix2. Plant J . 59: 600-611
  6. Bar, M., Sharfman, M., Ron M. and Avni A. (2010). BAK1 is required for the attenuation of Eix-induced defense responses by the decoy receptor LeEix1. Plant J.63: 791-800
  7. Sharfman M, Bar M, Ehrlich M, Schuster S, Melech-Bonfil S, Ezer R, Sessa G, Avni A. (2011) Endosomal signaling of the tomato leucine-rich repeat receptor-like protein LeEix2. Plant J 68, 413–423

Students and Lab Members

Who's in the lab

Lab Photos

Slide 2

Slide 3

Slide 4

Slide 5

Slide 6

Slide 7

Slide 8

Courses
  • Introduction of Plant Physiology and Biotechnology (compulsory undergraduate course)
  • New frontiers in biology (undergraduate course)
    Communication between genomes in eukaryotes (undergraduate course with Prof A. Breiman and Prof H. Fromm)
  • Current topics in plant biotechnology (undergraduate course with Prof  A. Zilberstein and Prof  A. Sharon)

Full Publications
  1. Soreq H., Zevin-Sonkin D., Avni A., Hall L. and Spierer P. A human acetylcholinesterase gene identified by homology to the Drosophila gene. Proc. Natl. Acad. Sci. USA 82,1985 (pp. 1827-1831).
  2. Zakut H., Matzkel A., Schechter E., Avni A. and Soreq H. Polymorphorism of acetylcholinesterase in discrete regions of the developing fetal human brain. J. Neurochem. 45,1985 (pp. 382-389).
  3. Zevin-Sonkin D., Avni A., Zisling R., Koch R. and Soreq H. Expression of acetylcholinesterase gene(s) in the human brain: Molecular cloning evidence for cross-homologous sequences. J. Physiol. (Paris) 80,1985 (pp. 221-228).
  4. Avni A., Edelman M., Rachailovich I., Aviv D. and Fluhr R. A point mutation in the gene for the large subunit of ribulose 1,5-bisphosphate carboxylase/oxygenase affects holoenzyme assembly in Nicotiana tabacum. Embo J. 8, 1989 (pp. 1915-1918).
  5. Avni A. and Edelman M. Direct selection of paternal inheritance of chloroplast in sexual progeny of Nicotiana . Mol. Gen. Genet 225, 1991 (pp. 273-277).
  6. Avni A., Avital S. and Gromet-Elhanan Z. Reactivation of the chloroplast CF1-ATPase ? by trace amount of CF1 ? subunit suggest a chaperonin-like activity for CF1 ?. J. Biol. Chem. 266, 1991 (pp. 7317-7320).
  7. Avni A, Mehta R.A., Mattoo A.K., Greenberg B.M., Chattoo B.B, Heller D. and Edelman M. Nucleotide sequence of the Spirodela oligorrhiza chloroplast psbA gene coding for the D1 (32 kDa) photosystem II protein. Plant Mol. Biol. 17, 1991 (pp. 919-921).
  8. Avni A., Anderson J.D., Holland N., Rochaix J-D., Gromet-Elhanan Z. and Edelman M. Tentoxin sensitivity of chloroplasts is determined by codon 83 of ?-subunit of proton-ATPase. Science 257, 1992 (pp.1245-1247).
  9. Bailey B.A., Avni A., Ning L., Mattoo A.K. and Anderson J.D. Nucleotide sequence of Nicotiana tabacum var. Xanthi gene coding for 1-Aminocyclopropane-1-carboxylate synthase. Plant Physiol. 100, 1992 (pp.1615-1616).
  10. Avni A., Bailey B.A., Mattoo A.K. and Anderson J.D. Induction of ethylene biosynthesis in Nicotiana tabacum by a Trichoderma viride Xylanase is correlated to the accumulation of ACC synthase and ACC oxidase. Plant Physiol. 106, 1994 (pp. 1049-1055).
  11. Acher A.J., Hapeman C.J., Shelton D.R., Muldoon M.T., Lusby W.R., Avni A. and Waters R. Comparison of formation and biodegradation of Bromacil oxidation products in aqueous solutions. J. Agric. Food Chem. 42, 1994 (pp. 2040-2047).
  12. Bailey B.A., Avni A. and Anderson J.D. The influence of ethylene and tissue age on the sensitivity of Xanthi tobacco leaves to a Trichoderma viride xylanase Plant Cell Physiol. 36, 1995 (pp.1669-1676).
  13. Hanania U. and Avni A. High Affinity Binding Site for Ethylene Inducing Xylanase Elicitor on Nicotiana tabacum Membranes. Plant J. 12, 1997 (pp. 113-120)
  14. Garty J., Kloog N., Wolfson R., Cohen Y., Karnieli A. and Avni A. The influence of air pollution on the concentration of mineral elements, on the reflectance response and on the production of stress-ethylene in the lichen Ramalina duriaei (De Not.) Bagl. New Phytol., 137, 1997 (pp. 587-597).
  15. Aloni R., Wolf A., Feigenbaum P., Avni A. and Klee H.J. The Never Ripe mutant provides evidence that tumor-induced ethylene controls the morphogenesis of Agrobacterium tumefaciens-induced crown galls on tomato shoots. Plant Physiol. 117, 1997 (pp. 841-849).
  16. Furman-Matarasso N., Cohen E., Du Q., Chejanovsky N., Hanania U. and Avni A. A Point Mutation in the Ethylene Inducing Xylanase Elicitor Inhibits the β-1-4-Endoxylanase Activity But Not the Elicitation Activity. Plant Physiol. 121, 1999 (pp. 345-351).
  17. Hanania U., Furman-Matarasso N., Ron M. and Avni A. Isolation of a novel SUMO protein from tomato that suppresses cell death in plants. Plant J. 19, 1999 (pp. 533-541)
  18. Ron M., Kantety R., Martin G.B., Avidan N., Eshed Y., Zamir D. and Avni A. High-resolution linkage analysis and physical characterization of the EIX-responding locus in tomato. Theor. Appl. Genet. 100, 2000 (pp. 184-189)
  19. Elbaz M, Avni A and Weil M. Constitutive caspase-like machinery executes programmed cell death in plant cells Cell Death Diff 9, 2002 (pp. 726-733)
  20. Sobolev V., Niztaev A., Pick U., Avni A. and Edelman M. A case study in applying docking predictions: modelling the tentoxin binding sites of chloroplast F1-ATPase. Current Science, 83, 2002 (pp. 1-11)
  21. Rotblat B., Enshel-Seijffers E., Gershoni J.M., Schuster S. and Avni A. Identification of an essential component of the elicitation active site of the EIX protein elicitor. Plant J. 32, 2002 (pp. 1049-1055
  22. Ron M. and Avni A. 

    23. The receptor for the fungal elicitor Ethylene-Inducing Xylanase is a member of a resistance-like gene family in tomato. Plant Cell 16, 2004 (pp. 1604-1615)

  23. Bonshtien A, Lev A, Gibly A, Debbie P, Avni A, Sessa S. Molecular properties of the Xanthomonas AvrRxv effector and   global transcriptional changes determined by its expression in resistant   tomato plants. Mol Plant-Microbe Int 18 , 2005 (pp. 300-310).
  24. Matarasso N, Schuster S, Avni A. 2005. A novel plant cysteine protease moonlights as a regulator of ACC synthase gene expression. Plant Cell 17, 2005 (pp. 1205-1216).
  25. Steindler, L., D. Huchon, A. Avni, and M. Ilan, 16S rRNA phylogeny of sponge-associated cyanobacteria. Applied and Environmental Microbiology, 2005. 71(7): p. 4127-4131.
  26. Magiri, E.N., O. Farchi-Pisanty, A. Avni, and A. Breiman, The expression of the large rice FK506 binding proteins (FKBPs) demonstrate tissue specificity and heat stress responsiveness. Plant Science, 2006. 170(4): p. 695-704.
  27. Steindler, L., S. Schuster, M. Ilan, A. Avni, C. Cerrano, and S. Beer, Differential gene expression in a marine sponge in relation to its symbiotic state. Marine Biotechnology, 2007. 9(5): p. 543-549.
  28. Bar, M., M. Aharon, S. Benjamin, B. Rotblat, M. Horowitz, and A. Avni, AtEHDs, novel Arabidopsis EH-domain-containing proteins involved in endocytosis. Plant Journal, 2008. 55(6): p. 1025-1038.
  29. Bar, M., S. Benjamin, M. Horowitz, and A. Avni, AtEHDs in endocytosis. Plant Signaling & Behavior, 2008. 3: p. 1008-1010.
  30. Bar, M. and A. Avni, EHD2 inhibits ligand-induced endocytosis and signaling of the leucine-rich repeat receptor-like protein LeEix2. Plant J, 2009.
  31. Bar, M. and A. Avni, EHD2 inhibits signaling of Leucine rich repeat receptor-like proteins. Plant Signaling & Behavior, 2009. 4
  32. Bar, M., and Avni, A. (2009b). EHD2 inhibits signaling of leucine rich repeat receptor-like proteins. Plant Signaling & Behavior 4, 1-3.
  33. Bar, M., Sharfman, M., Schuster, S., and Avni, A. (2009). The coiled-coil domain of EHD2 mediates inhibition of LeEix2 endocytosis and signaling. PLos One 4, e7973.
  34. Meiri, D., Tazat, K., Cohen-Peer, R., Farchi-Pisanty, O., Aviezer-Hagai, K., Avni, A., and Breiman, A. (2009). Involvement of Arabidopsis ROF2 (FKBP65) in thermotolerance. Plant Mol Biol 72, 191-203
  35. Dayan, J., Schwarzkopf, M., Avni, A., and Aloni, R. (2010). Enhancing plant growth and fiber production by silencing GA 2-Oxidase. Plant Biotechnology Journal 8, 1-11.
  36. Cohen-Peer, R., Schuster, S., Meiri, D., Breiman, A. and Avni A. (2010). SUMOylation of Arabidopsis heat shock factor A2 (HsfA2) modifies its activity during acquired thermotholerance. Plant Mol Biol doi:10.1007/s11103-010-9652-1
  37. Bar, M., Sharfman, M., Ron M. and Avni A. (2010). BAK1 is required for the attenuation of Eix-induced defense responses by the decoy receptor LeEix1. Plant Journal 63, 791-800.
  38. Bar, M., Sharfman, M. and Avni A. (2011) LeEix1 functions as a decoy receptor to attenuate LeEix2 signaling
    Plant Signaling & Behavior 6:455-457.
  39. Avni A. and Bla´zquez M. (2011) Can plant biotechnology help in solving our food and energy shortage in the future?
    Current Opinion in Biotechnology 22, 220-223
  40. Sharfman M, Bar M, Ehrlich M, Schuster S, Melech-Bonfil S, Ezer R, Sessa G, Avni A. (2011) Endosomal signaling of the tomato leucine-rich repeat receptor-like protein LeEix2. Plant J. 68, 387-399 .
Enter here specific template content