1

YARON SITRIT 10-01-2004

CURRICULUM VITAE

Personal details

Name: Yaron Sitrit

Date and place of birth:October 25, 1956, Tel Aviv, Israel.

Regular militaryservice: 1975-1978.

Address & telephone at work:The Institutes for Applied Research,

Ben-Gurion University of the Negev, Hashalom St. 1,

POB 653, Beer-Sheva, 84105, Israel

Tel: 972-8-6472705, Fax: 972-8-6472984

E-mail:

Address & telephone at home: Salit 38, Lehavim, Israel. Tel: 08-6512980.

Education

B.Sc.-1978-1981-The Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot.

M.Sc.-1982-1984- The Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot.

Under the supervision of Prof. Joseph Riov and Dr. Amos Blumenfeld.

Thesis: Regulation of ethylene biosynthesis during avocado fruit ripening. Thesis with distinction.

Ph.D.-1988-1993-The Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot.

Under the supervision of Prof. Ilan Chet and Prof. Amos Oppenheim.

Thesis: Molecular studies for improving biological control of soil-borne plant pathogenic fungi.

Employment History

1999-presentScientist Rank ‘C’ at the Institutes for Applied Research.

1997-1999 Post-doctoral fellow at the Department of Plant Genetics, Weizmann Institute of Science, Rehovot, Israel. Research Advisor: Prof. Avraham Levy.

1995-1997Post-Doctoral fellow at the Department of Vegetable crops, Mann Lab, University of California, Davis. Research Advisor: Prof. Alan B. Bennett.

1993-1994Post-doctoral fellow at the Department of Plant Genetics, Weizmann Institute of Science, Rehovot, Israel. Research Advisor: Prof. Avraham Levy.

1986-1987Research Assistant in the laboratory of Dr. A. Blumenfeld, at A.R.O

Professional Activities

2000-2003 Member of the “New Crops Committee” appointed by the chief scientist of the Israeli Ministry of Agriculture.

2003- Organizer of the first conference of C. peruvianus cactus growers and exporters in Israel.

Membership in professional/scientific societies

1996-2003 American Society of Plant Biologists

1994-2003 International Society of Plant Molecular Biology

1994-2003 The Israeli Society of Plant Sciences

Educational Activities

a. Current courses taught

Molecular Regulation of Fruit Ripening, graduate course, Department of life sciences.

b. Research students

  1. Racheli Ninio, M.Sc., 2002, Department of life sciences, co-supervisors: Prof Y. Mizrahi, Dr. E. Lewinsohn, A.R.O.
  2. Rachel Davidovitch, M.Sc., 2003, Department of life sciences, co-supervisors: Prof Y. Mizrahi.
  3. Edna Bahalul, M.Sc. Department of life sciences, co-supervisors: Dr. A Bustan, Dr. M Zaccai.
  4. Guy Hermosa, M.Sc., 2003, Department of life sciences, co-supervisors: Prof Y. Mizrahi and Dr. A. Nerd.
  5. Eylam Oron, M.Sc. Department of life sciences, co-supervisors: Prof Y. Mizrahi.
  6. Einat Vinter, M.Sc. Department of life sciences, co-supervisors: Prof Y. Mizrahi.
  7. Einav Golan, M.Sc. Faculty of Agriculture, co-supervisors: Dr. E. Lewinsohn, A.R.O.
  8. Li Young-Fang, PhD. Department of life sciences, co-supervisors: Dr. A Bustan, Dr. M

Zaccai.

  1. Anna Haimov, PhD. Department of life sciences, co-supervisors: Prof Y. Mizrahi.
  2. Marina Barski, PhD. Department of life sciences, co-supervisors: Prof Y. Mizrahi.
  3. Rachel Davidovitch, PhD. Department of life sciences, co-supervisors: Prof Y. Mizrahi and Dr. E. Lewinsohn, A.R.O.

Awards and Fellowships

a. Awards

1982-1984Fruit Board of Israel.

1988-2002Baron DeHirsh, Hebrew University, Graduate fellowship.

b. Fellowships

1993-1994Eshkol Fund, Fienberg School, Weizmann Institute of Science, Postdoctoral fellowship.

1995-1997BARD A.R.O, Postdoctoral Research Fellowship.

Scientific Publications

a. Refereed articles

1. Sitrit, Y., Riov, J. and Blumenfeld, A. (1986). Regulation of ethylene biosynthesis in avocado fruit during ripening. Plant Physiol. 81:130-135.

2. Sitrit, Y., Riov, J. and Blumenfeld, A. (1987). Ethylene biosynthesis in tissues of young and mature avocado fruits. Physiol. Plant. 69:505-510.

3. Sitrit, Y., Riov, J. and Blumenfeld, A. (1988). Interference of phenolic compounds with the 1-aminocyclopropane-1-carboxylic acid assay. Plant Physiol. 86:13-15.

4. Kless, H., Sitrit, Y., Chet, I. and Oppenheim, A.B. (1989). Cloning of the gene coding for chitobiase of Serratia marcescens. Mol. Gen. Genet. 217:471-473.

5. Sitrit, Y., Barak, Z., Kapulnik, Y., Oppenheim, A.B. and Chet, I. (1993). Expression of Serratia

marcescens chitinase gene in Rhizobium meliloti during symbiosis on alfalfa roots. Mol. Plant Micro. Inter. 6:293-298.

6. Sitrit, Y., Vorgias, C.E., Chet, I. and Oppenheim, A.B. (1995). Cloning and primary structure of the chiA gene from Aeromonas caviae. J. Bacteriol. 177:4187-4189.

7. Levy A.A., Fridlender M., Hanania U., Rubin E. and Sitrit Y. (1996). Binding of Nicotiana nuclear proteins to the subterminal regions of the Ac transposable element. Mol. Gen. Genet. 251:436-441.

8. Sitrit, Y. and Bennett A.B. (1998). Regulation of tomato fruit polygalacturonase mRNA accumulation by ethylene: A re-examination. Plant Physiol. 116:1145-1150.

9. Fridlender, M., Sitrit, Y., Gileadi, O., Shaul, O. and Levy, A. A. (1998). Analysis of the Ac promoter: structure and regulation. Mol. Gen. Genet. 258:306-314

10. Shalev, G., Sitrit, Y., Avivi-Ragolski, N., Lichtestein, C. and Levy, A. A. (1999). Stimulation of homologous recombination in plants by expression of the bacterial resolvase RuvC. Proc. Natl. Acad. Sci. USA 96:7398-7402.

11. Sitrit, Y., Bennett, A.B., Bradford, K. J. and Downie, B.A. (1999). Expression of a polygalacturonase associated with tomato seed germination. Plant Physiol. 121:419-428.

*12. Pelah, D., Kaushik, R. M., Mizrahi, Y., and Sitrit, Y. (2002). Organogenesis in the vine cactus Selenicereus megalanthus (yellowpitaya) using thidiazuron. Plan. Cell, Tiss. Orga. Cult. 71:81-84.

*13. Nerd, A., Sitrit, Y., Kaushik, R. A., and Mizrahi, Y. (2002). High summer temperatures inhibit flowering in vine pitaya crops (Hylocereus spp.). Scien. Hort. 1829:1-8.

*14. Ninio, R., Lewinsohn, E., Mizrahi, Y., and Sitrit Y. (2003). Changes in sugars, acids, and volatiles during ripening of koubo [Cereus peruvianus (L.) Miller] fruits. J. Agric. Food Chem. 51:797-801.

*15. Sitrit, Y., Stephnie, L., Ninio, R., Dishon, E., Bar, E., Lewinsohn, E., and Mizrahi, Y. (2003). Characterization of monkey orange (Strychnos spinosa Lam.), a potential new crop for arid regions. J. Agric. Food Chem. 51:6256-6260.

*16. Ninio, R., Lewinsohn, E., Mizrahi,Y., and Sitrit Y. (2003). Quality attributes of stored koubo [Cereus peruvianus (L.) Miller] fruit. Postharvest Biol. Technol. 30:273-280.

*17. Mizrahi, Y., Mouyal, J., Nerd,A., and Sitrit, Y. (2003). Metaxenia in the Vine Cacti Hylocereuspolyrhizus and Selenicereus spp. Annals Bot. In Press.

*Since last promotion

b. Chapters in Books

  1. Mizrahi, Y., Nerd, A., and Sitrit, Y. (2002). New fruits for arid climates. In: New Crops and New Uses: Strength in Diversity, the Proceedings of the Fifth National New Crops Symposium. Janick, J. Ed. ASHS Press, Alexandria, VA. Pp 378-384.

c. Unrefereed professional articles and publications

  1. Blumenfeld, A. and Sitrit, Y. (1986). Avocado fruit ripening and ethylene biosynthesis. Acta Hort., 179:787-791.

d. Published Scientific Reports and Technical Papers

  1. Mizrahi Y., Nerd A., and Sitrit Y. (2000) Market derivedR&D in Pitaya. A report submitted to the Chief Scientist, MOAG.
  2. Mizrahi Y., Nerd A., and Sitrit Y. (2000)Possible solution to marketing problem posed by concentrated fruit ripening in Hylocereus species. Report to: Ben Geffen Family Fund
  3. Mizrahi Y., Sitrit Y., and Nerd A. (2001) Solutions to marketing problems imposed by concentrated ripening of Hylocereus fruits. Submitted to Harry Stern Fund (BGUN-ARI-18-2001).
  4. Mizrahi Y., Nerd A., and Sitrit Y. (2001) Market derivedR&D in Pitaya. A report submitted to the Chief Scientist, MOAG.
  5. Nerd A., Sitrit Y., and Mizrahi Y. (2001) Adaptation of two vine cacti crops (red pitayas) to different regions of Israel. Richard and Ronnie Siedenberg Fund (BGUN-ARI—21-2001).
  6. Nerd A., Sitrit Y., and Mizrahi Y. (2001) Expanding the fruit period of red and yellow pitayas-new vine cactus crops for export. Submitted to Mr. Ben and Mrs. Arline Guefen Foundation (BGUN-ARI-36-2001).
  7. Sitrit Y., and Nerd A. (2002) Development of seed less cactus pear for export.A report submitted to the Chief Scientist, MOAG.
  8. Ben-Asher J., Sitrit Y., Sintov A., and Mizrahi Y. (2002) Use of Nopalea cochenillifera as a hypoglycemic product to control diabetes mellitus. A report submitted to Ministry of Science MOP.
  9. Mizrahi Y., Nerd A., and Sitrit Y. (2002) Market derivedR&D in Pitaya. A report submitted to the Chief Scientist, MOAG.
  10. Bustan A., Sitrit Y., and Zaccai M. (2002) Isolation and characterization of a genefamily encoding for Na+/H+ antiporters from the roots of the halophyte Distichlis spicata. A report submitted to the Chief Scientist, MOAG.
  11. Bustan A., Sitrit Y., and Zaccai M. (2002)Isolation and characterization of a genefamily encoding for Na+/H+ antiporters from the roots of the halophyte Distichlis spicata. A report submitted to the Vice President of BGU (BGUN-ARI-24-2002).
  12. Zaccai M., Shillo R., Bustan A., Sitrit Y., and Cohen A. (2002) Improving the performance of flowering bulbs (geophytes) by introducing genes that regulate plant resistance to heat, drought and salinity stress. Report submitted to the Joint Korean-Israeli Grant in the Field of Biotechnology.
  13. Sitrit Y., and Nerd A. (2003) Development of seed less cactus pear for export.A report submitted to the Chief Scientist, MOAG.
  14. Ben-Asher J., Sitrit Y., Sintov A., and Mizrahi Y. (2003) Use of Nopalea cochenillifera as a hypoglycemic product to control diabetes mellitus. A report submitted to Ministry of Science MOP.
  15. Mizrahi Y., Nerd A., and Sitrit Y. (2003) Market derivedR&D in Pitaya. A report submitted to the Chief Scientist, MOAG.

Lectures and Presentations at Meetings

Lectures

1.Sitrit, Y., Chet, I., Barak, Z. and Oppenheim, A.B. (1991). Genetic engineering of Rhizobia sp. for serving as biocontrol agents. Abstract In: Proceedings of the International Symbiosis Congress, November 17-22, 1991, Jerusalem, Israel.

  1. Sitrit, Y., Fridlender, M., Gileadi, O., Shaul, O. and Levy, A. A. (1998). Analysis of the Ac promoter: structure and regulation. Annual Meeting of The Israeli Plant Sciences Society, Volcani, ARO.
  2. Sitrit, Y., Lewinsohn, E., Ninio, R., and Mizrahi,Y. (2003). Storage improves the quality of Cereus peruvianus fruit. Abstract In: APEC Symposium on Postharvest Handling Systems, September 1-3, 2003, Bangkok, Thailand. O-01.
Posters

1.Sitrit, Y., Barak, Z., Oppenheim, A., Kapulnik, Y. and Chet, I. (1993). International Conference on Mechanisms of Plant Defense Responses, Strasbourg, France.

Cloning, expression and antifungal activity of Serratia marcescens chitinase gene in Rhizobium meliloti. p. 454. In: Developments in Plant Pathology, Mechanisms of Plant Defense Responses (B. Fritig and M. Legrand, eds.). Kluwer Academic Press, pp. 480

  1. Sitrit Y., Downie, B., Bennett, A.B. and Bradford, K.J. (1996). A novel exo-polygalacturonase is associated with radicle protrusion in tomato (Lycopersicon esculentum) seeds. Plant physiol. abs. 1996 ASPP Annual Meeting.
  2. Shalev, G., Sitrit, Y., Avivi-Ragolski, N., Lichtestein, C. and Levy, A. A. (1999). Over-expression of RuvC in plants is associated with an increased frequency of homologous recombination. IX international congress on plant tissue and cell culture. Jerusalem, Israel.
  3. Nerd, A., Sitrit, Y., and Mizrahi, Y. (2000). Harvest and storage conditions for fruits of pitayas. In the abstracts of Postharvest 2000. Jerusalem, March 26-31, page 55.
  4. Ninio R., Sitrit Y., Lewinsohn E., and Mizrahi Y. (2001). Accumulation and formation of flavor compounds in Cereus peruvianus fruit during ripening. Annual meeting of The Israeli Society of Plant Sciences P-28.
  5. Sitrit, Y., Ninio, R., Mizrahi, Y., and Lewinsohn, E. (2001). Formation and changes in flavor compounds in fruits of apple cactus (Cereus peruvianus) during ripening. 24th international symposium on natural products chemistry: current trends in natural products. Mexico city, November 04-10, Revista Latinoamerica De Quimica supl. BT-21, pp 100.
  6. Zaretsky, M., Sitrit, Y., Mills, D., Kagan-Zur, V. and Roth-Bejerano N. (2003). Gene expression during establishment of mycorrhizal association between Cistus hairy roots and Terfezia boudieri isolates. Abstract In: The Fourth International Conference on Micorrhizae. ICOM4, August, 10-15, Montreal, Canada. 279, page 313.
  7. Lewinsohn, E., Sitrit, Y., Stephnie, L., Ninio, R., Dishon, E., Bar, E., and Mizrahi, Y. (2003). Flavor determinants of Monkey orange fruits (Strychnos spinosa Lam.) during storage. Abstract In: APEC Symposium on Postharvest Handling Systems, September 1-3, 2003, Bangkok, Thailand. P-03.
Research Grants

1.1999-2004, financed by the Chief Scientist of Ministry of Agriculture. PI Y. Mizrahi, CO A. Nerd, Y. Sitrit. Pitaya Fruits R&D Activity Dictated by Export Market Needs. For 5 years. 1999-2000 $73,000, 2000-2001 $60,000, 2003-2005 $108,000. Total- $241,000.

  1. 2000-20002, Joint Korean-Israeli Research Grant in the field of plant biotechnology. PI M. Zaccai, CO A. Bustan, Y. Sitrit. Improving the performance of flowering bulbs (geophytes) by introducing genes that regulate plant resistance to heat, drought and salinity stress. For 2 years $24,000/Year-Total-$48,000.
  2. 2001, Internal BGU grant upon excellent review by GIF fund. PI A. Bustan, CO M. Zaccai, Y. Sitrit. Cloning of antiporter gene from saltgrass to improve salt tolerance. Only 1 year $10,000.
  3. 2000-2003, Ministry of Agriculture, PI Y.Sitrit CO A. Nerd, Parthenocarpy in prickly pear. For 3 years $18,600/Year. Total-$56,000.
  4. 2002-2005, Ministry of Agriculture. PI A. Bustan, CO M. Zaccai, Y. Sitrit. Cloning of antiporter gene from saltgrass to improve salt tolerance. For 3 years $35,000/year. Total- $105,000.
  5. 2002-2005, Ministry of Science PI Y. Ben-Asher, CO Y. Mizrahi, A. Sintov, Y. Sitrit. Use of Nopalea cochenillifera as a natural hypoglycemic product to control diabetes mellitus. For 3 years $22,000/year. Total- $66,000.

Synopsis of Research

Our research concerns the introduction of rare and wild fruit trees as new crops and the possibilities of developing a wide range of products from the new crops. On the basis of ethno-botanical knowledge, we are screening these newly introduced plants to identify bioactive compounds towards the development of new therapeutic agents and food supplements from natural sources. The research includes studies of secondary metabolites (in particular the development of aroma compounds during fruit ripening) and of compounds with therapeutic activities. My current activities focus on:

Development of seedless prickly pear fruits;

Study of valuable secondary metabolites in cactus plants: including determination of aroma volatiles in different fruits and investigation of hypoglycemic activity to control diabetes and of other pharmaceutical activities;

Development of argan (Argania spinosa) tree as an oil crop;

Development of C. peruvianus cactus tree as an export crop;

Molecular regulation of non-climacteric fruit ripening in cacti plants;

Development of molecular tools for cactus breeding, including RNA and DNA extraction, and transformation protocols;

Isolation of genes encoding for salt tolerance from Distichlis spicata (in collaboration with Dr. A. Bustan and Dr. M. Zaccai);

Studying the molecular basis of water stress tolerance in cactus plants and the isolation of a gene family encoding for aquaporin water channels.

Some subjects with applied potential are presented in greater detail below.

  • Development of molecular tools for cacti study. In general, molecular tools and working methodologies are under-developed in cacti plants. To develop such tools I started an on going project to develop transformation protocols in cacti and the first step of tissue culture regeneration protocols in Selenicereus megalanthus were carried and published Plan. Cell, Tiss. Orga. Cult. 71:81-84. Working at the molecular level requires employment of non-trivial methods in order to successfully extract nucleic acids from tissues which are highly reach in polysaccharides. Currently, we adopted protocols for developing AFLP markers and using this method successfully both at the DNA and RNA levels financed by the Ministry of Agriculture (seedless prickly pear). This breakthrough enabled us to clone a gene family encoding for water channels in Opuntia ficus-indica. Also protocols for extracting plant hormones including ABA and IAA were adopted and employed routinely in the lab.
  • Drought response of O. ficus-indica: changes in ABA levels and expression of aquaporins gene family. Opuntia ficus-indica is a succulent cactus plant that can survive prolonged drought mainly by the utilisation of the water conserving Crassulacean Acid Metabolism (CAM) photosynthetic pathway. During drought, water is preferentially lost from the water-storage parenchyma rather than from the photosynthetic chlorenchyma. Anatomical cross-sections show that most of the vascular system is located along the border of the chlorenchyma and parenchyma, indicating that most of the radial water transport is exerted through symplastic, apoplastic and transmembranal pathways. Transmembrane water movement in plants is a fundamental process carried out by water channel proteins, aquaporins (AQP). In this work we characterised the physiological, hormonal and aquaporins genes expression changes in Opuntia ficus-indica during exposure to drought stress. Small decrease of about 5% in the relative water content (RWC) of the chlorenchyma was found only after 30 days of drought, in contrast to the parenchyma, in which the RWC decreased gradually by 30%. Abscisic acid (ABA) content increased gradually in both tissues, with levels tripled in the chlorenchyma and quadrupled in the parenchyma. ABA content was also examined during the diurnal course of watered plants, as some evidence indicate diurnal changes in ABA content. Diurnal changes in abscisic acid content were found in the parenchyma, chlorenchyma and in the epidermis of watered plants. Abscisic acid content increased two hours before stomatal closure in the morning, stayed at high levels during the day and dropped in the late afternoon, towards stomatal opening. These results suggest that abscisic acid may have a role in the regulation of the diurnal activity of the plant, especially the course of stomatal closure and opening. Eeight genes of AQPs were isolated and partially sequenced. Sequence homology and phylogenetic relationships between Opuntia ficus-indicacDNA clonesand other plant MIP proteins showed that the eight genes belong to the MIP family. All genes showed high homology (82-95% identity) to aquaporines isolated from the CAM facultative plant- M. crystallinum. The expression of four genes was studied in the parenchyma, chlorenchyma and roots. The results indicate that during drought water is transported from the water storage parenchyma to the metabolically active chlorenchyma and that this process requires an increase in aquaporin content especially in the tonoplast. The rise in the abscisic acid content implies that the increase in gene expression may be regulated by the abscisic acid.
  • Ripening characteristics of argan fruits. Argan trees, which are native to Morocco, grow in the wild in the arid parts of that country. The fruits are used for animal feed, and the stony seeds are collected for oil extraction. With the aim of establishing a new crop tree in Israel, the species was introduced some years ago and planted in a variety of eco-zones. Previous studies in our lab addressed the growth and reproductive biology of argan trees, oil production and vitamin E content in the oil. Ripening of argan fruit is characterized by climacteric production of ethylene. Aroma develops at the onset of ripening, the main aroma substances being lactones. Currently, we are characterizing the aroma volatiles and the biosynthetic pathways involved in aroma production (in collaboration with Prof. Y. Mizrahi and Dr E. Lewinsohn).
  • Ripening of koubo. During ripening, koubo (Cereus peruvianus) fruits develop a distinct aroma. The profile of the aroma volatiles is currently being determined. Preliminary results indicate that the major constituent is linalool and that linalool synthase activity is found in ripening fruit. The alterations in sugar and acid compositions during ripening are also under characterization (in collaboration with Prof. Y. Mizrahi and Dr E. Lewinsohn). Published in J. Agric. Food Chem. 51:797-801 and Postharvest Biol. Technol. 30:273-280.
  • Hypoglycemic activity in stem preparations from nopalito species. The hypoglycemic activity of preparations from Opuntia species and from Nopalea cochenillifera was determined in a model rat system. Acetone extracts of cactus stems, partially purified by means of a number of chromatographic methods, were administered intraperitoneally to streptozotocin-induced diabetic rats. A significant reduction in blood glucose levels was evident within 8 h. Currently; we are attempting to further purify the active component in order to identify its chemical structure (in collaboration with Dr. A. Sintov Dr. S. Ben-Shabat, and Prof. Y. Mizrahi). Financed by the Ministry of Science.

Present Academic Activity

Articles to be published

a. In preparation

1. Sitrit Y., Ninio R., Bar E., Golan E., Larkov O., Ravid U., and Lewinsohn E. (2004) S-Linalool synthase activity in the fruit of the columnar cactus koubo [Cereus peruvianus (L.) Miller].

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