Arthur A. Schaffer Ph.D.

Research Interests

The general strategy 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., Syngenta and BreedX, 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. Among these varieties are the Nebula variety which is characterized by an unusually high ratio of fructose to glucose, based on the introgression of a wild allele for a sugar transporter. 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.

More recently the research group has uncovered the metabolic pathway of mogroside biosynthesis in the Chinese plant Siraitia grosvenorii (monk fruit). Mogrosides are natural non-sugar sweeteners and the identification of the novel genes involved in its unique metabolic pathway has led to the founding of an Israeli Agbiotech Start Up,  NatureSweet, dedicated to producing the sweetener commercially .

Current Projects

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

Research Group

Staff

Dr. Marina Petreikov, Ph.D.  retired volunteer                                                
Dr. Yelena Yeselson, Ph.D.

Dr. Umar Gani, visiting postdoc

Past Doctoral Students:

Dr. Shahar Cohen
Dr. Arik Shamai
Dr. Noam Chehanovsky

Dr. Dafna Miron
Dr. Yosi Burger

Dr. Michal Moi

Dr. Ran Hovav

Dr. Marina Petreikov

Past PostDocs:

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

Dr. Michal Moi

Dr. Shahar Cohen

Dr. Max Itkin

Dr. Guy Polturak

Past staff:

Shmuel Shen

Zecharia Bnei Moshe

Miriam Fogelman

Dvir Cohen