Research Interests

The general interest of the research group is to identify and characterize useful genetic variability within the Lycopersicon spp., Cucumis melo and Cucurbita spp. for its use in breeding for tomatoes, melons and pumpkins with improved fruit quality. The group has a special interest in understanding the molecular control of the evolution of quality traits under domestication.

We carry out research projects on sugar, starch and organic acid metabolism in order to determine rate limiting steps in accumulation of quality components. We have recently concluded the cloning of the genes encoding for the complete metabolic pathways of sugar and acid metabolism in melon fruit.

We've also developed, in a joint research and development program with the Gedera Seed Co., tomato hybrids with modified sugar content based on introgressions from the wild species L. hirsutum and we are studying the genetic-molecular control of these variations. Cultivars of tomatoes with a unique trait of fruit dehydration while still attached to the vine have been developed in conjunction with the Tomaisin Corp. The gene controlling the trait has been cloned using a map-based cloning strategy.

The research group is also part of the Center for the Genetic Improvement of Cucurbit Fruit Quality, an ad hoc organization of research groups with multidisciplinary expertise in germplasm, genetics, genomics and biochemistry of the major fruit quality components of the cucurbits. The Center's activities are being carried out with support from The Ministry of Industry and Commerce Bio-Tov project, The Ministry of Science, The Chief Scientist of the Ministry of Agriculture, EU Meta-Phor project, BARD and industry grants.

Current Projects

• Biochemistry and genetic control of sugar accumulation in tomato fruit
• Molecular biology of carbohydrate metabolism in melon fruit
• Development of Raisin tomatoes (Tomaisins)
• Genetic control of starch metabolism and accumulation in tomatoes and squash
• Development of melons with increased acid levels

Research Group

Staff

Marina Petreikov, Ph.D.                                                  
Yelena Yeselson, Ph.D.
Shmuel Shen
Michal Moi

Doctoral Students:

Shahar Cohen
Arik Shamai
Noam Chehanovsky

Past Doctoral Students:

Dr. Dafna Miron
Dr. Yosi Burger
Dr. Ran Hovav
Dr. Marina Petreikov

Past PostDocs:

Dr. Rivka Hadas
Dr. Gao Zhifang
Dr. Genfa Zhang
Dr. Nir Carmi
Dr. Nir Dai

                                      Recent Publications

Quick, P. and Schaffer, A.A. 1996. "Sucrose Metabolism in Sources and Sinks". Ch. 6, In: Photoassimilate Distribution in Plants and Crops: Source-Sink Relationships, E. Zamski and A.A. Schaffer, eds Marcel Dekker, Inc., N.Y., pp. 115-156

Schaffer, A.A., Pharr, D.M. and M. Madore. 1996. "Cucurbits". Ch. 29, In: Photoassimilate Distribution in Plants and Crops: Source-Sink Relationships, E. Zamski and A.A. Schaffer, eds Marcel Dekker, Inc., N.Y., pp. 729-757

Schaffer, A.A. and Petreikov, M. 1997a. Sucrose to Starch Metabolism in Tomato Fruit Undergoing Transient Starch Accumulation. Plant Physiology 113:739-746

Kanayama, Y., Dai, N., Granot, D., Petreikov, M., Schaffer, A., Bennett, A.B. 1997. Divergent Fructokinase Genes are Differentially Expressed in Tomato. Plant Physiology 113:1379-1384

Aloni, B., Karni, L., Zaidman, Z., Schaffer, A.A. 1997. The Relationship Between Sucrose Supply, Sucrose-Cleaving Enzymes and Flower Abortion in Pepper. Ann. Bot. 79: 601-605

Dai, N., Schaffer A., Petreikov M. and Granot D. 1997. Potato (Solanum tuberosum L.) fructokinase expressed in yeast exhibits inhibition by fructose of both in vitro enzyme activity and rate of cell proliferation. Plant Science 128:191-197

Kanayama Y., Granot D., Dai N., Petriekov M., Schaffer A., Powell A. and Bennett A. B. 1997. Tomato fructokinases exhibit differential expression and substrate regulation. Plant Physiology 117:85-90

Schaffer, A.A. and Petreikov, M. 1997. Inhibition of fructokinase and sucrose synthase by cytosolic levels of fructose in young tomato fruit undegoing transient starch synthesis. Physiologia Plantarum 101:808-816.

Gao, Z. and Schaffer, A.A. 1999. A novel alkaline alpha-galactosidase from melon fruit with substrate preference for raffinose. Plant Physiology 119:979-988

Gao, Z. Zamski, E., Petreikov, M. and Schaffer, A.A. 1999. Carbohydrate metabolism during early fruit development of sweet melon (Cucumis melo). Physiologia Plantarum 106:1-8.

Dai N., Schaffer A., Petreikov M., Shahak Y., Giller Y., Ratner K., Levine A. and Granot D. 1999. Overexpression of Arabidopsis hexokinase in tomato plants inhibits growth, reduces photosynthesis and induces rapid senescence. Plant Cell 11:1253-1266

Schaffer A., Petreikov M., Miron D., Fogelman M., Spiegelman M., Bnei-Moshe Z., Shen S., Granot D., Hadas R., Dai N., Levine I., Bar M., Friedman M., Pilowsky M., Gilboa N. and Chen L. 1999. Modification of carbohydrate content in developing tomato fruit (colloquium paper). Hortscience 34:12-15

Stepansky, A. Kovalski, I., Schaffer, A. and Perl-Treves. R. 1999. Variation in sugar levels and invertase activity in mature representing a broad spectrum of Cucumis melo genotypes. Genetic Res. Crop Evolution. 46:53-62

Cohen, S., Schaffer, A.A., Shen, S., Spiegelman, M., Bnei-Moshe, Z., Cohen, S. and Sagi, M. 2000. Light distribution and canopy structure in greenhouse muskmelon. Acta Horticulturae 507:17-24

Levin, I., Gilboa, N., Yeselson, E., Shen, S., Schaffer, A.A. 2000. Fgr, a major locus that modulates the fructose to glucose ratio in mature tomato fruits. Theoretical Applied Genetics 100:256-262

Schaffer, A.A., Levin, I., Oguz, I., Petreikov, M., Cincarevsky, F., Yeselson, L., Shen, S., Gilboa, N., Bar, M. 2000. ADPglucose pyrophosphorylase activity and starch accumulation in immature tomato fruit: the effect of a Lycopersicon hirsutum-derived introgression encoding for the large subunit. Plant Science 152:135-144

Menu, T, Rothan, C., Dai, N., Petreikov, M., Etienne, C., Destrac-Irvine, D., Schaffer, A., Granot, D., Ricard, B. 2001. Cloning and characterization of a cDNA encoding hexokinase from tomato. Plant Science 160:209-218

Miron, D., Petreikov, M., Carmi, N., Shen, S., Levin, I., Granot, D., Zamski, E., Schaffer, A.A. 2001. Invertase localization, gene expresion, and sucrose uptake in developing fruit of L. esculentum and in the sucrose-accumulating L. hirsutum. Physiologia Plantarum 115:35-47

Petreikov, M, Dai, N., Granot, D. and Schaffer, A.A. 2001. Fructokinase isozymes in developing tomato fruit pericarp. Phytochemistry 58:841-847

Dai, N., German, M., Matsevitz, T., Hanael, R., Swartzberg, D., Yeselson, Y., Petreikov, M., Schaffer, A.A., Granot, D. 2001. LeFRK2, the gene encoding the major fructokinase in tomato fruits, is not required for starch biosynthesis in developing fruits. Plant Science 162:423-430

Burger, Y. Yeselson, L, Sahar, U., Paris, H., Katzir, N., Levin, I., Schaffer, A.A. 2002. A single recessive gene for sucrose accumulation in Cucumis melo fruit. Journal Amer. Soc. Hort. Sci. 127:938-943

Dai, N., Kandel, M., Petreikov, M., Hanael, R., Levine, I., Ricard, B., Rothan, C., Schaffer, A.A., Granot, D. 2002. Cloning, mapping, characterization and expression analysis of tomato hexokinase LeHXK1 Plant Science 163:581-590

Davash, L., Dag, A., Kammer, Y., Afik, O., Kelev, H., Shafir, S., Schaffer, A., Yeselson, Y., Efrat, H., Slavetzki, Y., Noy, M., Kalif, L. Landau, J. 2002. Determination by near-infrared spectroscopy of perseitol used as a marker for the botanical origin of avocado (Persea americana Mill.) honey. Journal of Agriculture and Food Chemistry 50:5283-5287

German M.A., Dai N., Chmelnitsky I., Sobolev I., Salts Y., Barg R., Schaffer A.A. and Granot D. 2002. LEFRK4, a novel tomato (Lycopersicon esculentum Mill.) fructokinase specifically expressed in stamens. Plant Science 163:607-613

Carmi N, Zhang G., Petreikov M., Gao Z., Eyal Y., Granot D., and Schaffer, A.A. 2003. Cloning and functional expression of alkaline β-galactosidase from melon fruit: similarity to plant SIP proteins uncovers a novel family of plant glycosyl hydrolases. Plant Journal: 33:87-96

Schaffer, A.A. and H.S. Paris. 2003. Melons, squashes and gourds. In: Encyclopedia of Food Sciences and Nutrition, B. Caballero et al., eds, Academic Press, N.Y.

German MA, Dai N, Matsevitz T, Hanael R, Petreikov M, Bernstein N, Ioffe M, Shahak Y, Schaffer AA, Granot D. 2003. Suppression of fructokinase encoded by LeFRK2 in tomato stem inhibits growth and causes wilting of young leaves. Plant Journal 34:837-46.

Burger, Y., Sa'ar, U., Distelfeld, A., Katzir, N., Yeselson, Y, Shen, S. and Schaffer, A.A. 2003. Developing of sweet melon (Cucumis melo) genotypes combinig high sucrose and organic acid content. Journal Amer. Soc. Hort. Sci. 128: 537-540.

Levin, I., Lalazar, A., Bar, M. and Schaffer, A.A. 2004. Non GMO fruit factories. Modulating metabolic pathways in the tomato fruit. J. of Industrial Crops and Products, 20: 29-36.        

Gao, Z., Petreikov, M., Burger, Y., Shen, S. and Schaffer, A.A. 2004. Stachyose to sucrose metabolism in sweet melon (Cucumis melo) fruit mesocarp during the sucrose accumulation stage. Proc. Cucurbitaceae 2004 (ed. A. Lebeda and H.S. Paris). Progress in Cucurbit Genetic and Breeding. Pp. 471-475.

German, MA, Asher, I, Petreikov, M, Dai, N, Schaffer AA, Granot, D. 2004. Cloning, expression and characterization of LeFRK3, the fourth tomato (Lycopersicon esculentum Mill.) gene encoding fructokinase. Plant Science 166: 285-291.

Burger, Y., Yeselson, Y., Saar, U., Paris, H.S., Katzir, N., Tadmor, Y. and Schaffer, A.A. (2004). Screening of melon (Cucumis melo) germplasm for consistently high sucrose content and for high ascorbic acid content.  Proc. Cucurbitaceae 2004 (ed. A. Lebeda and H.S. Paris). Progress in Cucurbit Genetic and Breeding. pp 151-155.

Yariv, Y., Portnoy, V., Burger,Y., Benyamini, Y., Lewinsohn, E., Tadmor, Y., Ravid, U., White, R., Giovannoni, J., Schaffer, A.A. and Katzir, N. (2004).Isolation and characterization of fruit-related genes in melons (Cucumis melo) using SSH and macroarray techniques. Proc. Cucurbitaceae 2004 (ed. A. Lebeda and H.S. Paris). Progress in Cucurbit Genetic and Breeding., pp. 491-497.

Tadmor, T., Paris, H.S., Meir, A., Schaffer, A.A and Lewinsohn, E. 2005. The dual role of the pigmentation gene B in affecting carotenoid and Vitamin E content in pumpkin (Cucurbita pepo) mesocarp.  J. Agric. Food Chem. 53: 9759-9763.

Dag, A., Afik, O., Yeselson, Y., Schaffer, A. And Shafir, S. 2005. Physical, chemical and palynological characterization of avocado (Persea americana Mill) honey in Israel. Int. J. Food. Sci. Tech. 40: 1-8.

Ibdah, M., Azulay, Y., Portnoy, V., Wasserman, B., Bar, E., Meir, A., Burger, Y., Hirschberg, J., Schaffer, A.A., Katzir, N., Tadmor, Y., and Lewinsohn, E. 2006. Functional characterization of CmCCD1, a carotenoid cleavage dioxygenase from melon. Phytochemistry 67: 1579-1589.

Dai N., Petreikov M., Portnoy V., Katzir, N., Pharr D. M., Schaffer A. A. 2006. Cloning and expression analysis of a UDPgalactose/glucose pyrophosphorylase from melon fruit provides evidence for the major metabolic pathway of galactose metabolism in raffinose oligosaccharide metabolizing plants. Plant Physiol. 142:294-304.

Petreikov M., Shen S., Yeselson Y., Levin I., Bar M., Schaffer AA. 2006. Temporally extended gene expression of the ADPglucose pyrophosphorylase large subunit (AGPase-LS1) leads to increased enzyme activity in developing tomato fruit. Planta 224:1465-1479.

Paris, H. S. Burger Y. and Schaffer A. A. 2006.Genetic variability and introgression of horticulturally valuable traits in squash and pumpkins of Cucurbita pepo. Israel Journal of Plant Sciences 54: 243-249.

Levin, I., Gilboa, N., Cincarevsky, F., Oguz, I., Petreikov, M., Yeselson, Y., Shen, S., Bar M. and Schaffer A.A. 2007. Epistatic interaction between the Fgr and FK2 genes determines the fructose to glucose ratio in mature tomato fruit. Israel Journal of Plant Sciences 54:

Burger, Y., Sa'ar, U., Paris, H. S., Lewinsohn, E., Katzir, N., Tadmor Y. and. Schaffer A. A 2007. Genetic variability as a source of new valuable fruit quality traits in Cucumis melo. Israel Journal of Plant Sciences 54: 233-242.

Burger, Y. and Schaffer, A.A. 2007. The contribution of sucrose metabolism enzymes to sucrose accumulation in Cucumis. Journal Amer. Soc. Hort. Sci. 132:704-712.

Hovav R, Chechanovsky N, Moi M, Jetter R, Schaffer AA. 2007. The expression of a single gene (Cwp), silenced during Solanum evolution, causes fruit cuticle microfissuring and dehydration in tomato Plant Journal 52:627-639.

Portnoy, V., Benyamini, Y., Bar, E., Harel-Beja, R., Gepstein, S., Giovannoni, J.J. Schaffer, A.A., Burger, J., Tadmor, Y.,  Lewinsohn, E. and Katzir, N.  2008. The molecular and biochemical basis for varietal variation in sesquiterpene content in melon (Cucumis melo L.) rinds. Plant Molecular Biology 66:647-661.

Tadmor, Y., Katzir, N., Meir, A., Yaniv-Yaakov, A., Sa'ar, A., Baumkoler, F., Lavee, T., Lewinsohn, E., Schaffer, A.A. and Burger, J. 2008. Induced mutagenesis to augment the natural genetic variability of melon (Cucumis melo L.). Israel Journal of Plant Sciences (In Press(

Lewinsohn, E.,  Portnoy, V., Benyamini, Y., Bar, E., Harel-Beza, R., Gepstein, S., Giovannoni, J.J, Schaffer, A.A., Burger, J., Tadmor, Y., and Katzir, N. 2008. Sesquiterpene aroma biosynthesis in melon (Cucumis melo) rinds. Proceedings of the 9th EUCARPIA meeting ‘Cucurbitaceae 2008', Avignon, France.

Katzir, N., Harel-Beja, R., Portnoy, V., Tzuri, G., Koren, E., Lev, S., Bar, E., Paris, H., Tadmor, Y. Burger, J., Lewinsohn, E., Fei, Z., Giovannoni, J.J, and Schaffer, A.A., (2008). Melon fruit quality: a genomic approach. Proceedings of the 9th EUCARPIA meeting ‘Cucurbitaceae 2008', Avignon, France.

Burger, Y., Paris, H. S., Cohen, R., Katzir, N. and Schaffer, A.A. 2008. Genetic diversity of Cucumis melo. Hort. Rev. (in press).

Publications in the field of Judaica- Botanical history

Schaffer, A.A.. 1981. The History of Horseradish as the Bitter Herb of Passover. Gesher 8: 217-237. (pdf)

Schaffer, A.A. 1982. The Agricultural and Ecological Symbolism of the Four Species of Sukkot. Tradition 20(2): 128-140. (pdf)

 Maror- its history and taste physiology. Powerpoint presentation, yeshivat Har Etzion, April 7, 2011 (link)