CHARACTERIZATION OF RAFFINOSE AND STACHYOSE SYNTHASE GENES BY USING TILLING BY SEQUENCING+

Author

Erdem Anil, Southern Illinois University CarbondaleFollow

Date of Award

12-1-2024

Degree Name

Master of Science

Department

Plant, Soil, and Agricultural Systems

First Advisor

Meksem, Khalid

Abstract

Soybean (Glycine max) is one of the most widely grown crops in the world. Soybeans are used as food and feed products due to their high protein, oil, and carbohydrate seed contents. Soybeans are one of the most important protein sources presenting several benefits for human and animal consumption. Moreover, the carbohydrate content of soybean is important since it contributes to the taste of soyfood such as tofu, soymilk, natto, and livestock. Sucrose is the predominant carbohydrate found in soybeans which is followed by other raffinose family oligosaccharides (RFOs) such as raffinose and stachyose. Higher sucrose contents contribute to improving the digestibility of products. However, higher raffinose and stachyose contents make soymeal indigestible and can cause undesirable flatulence in humans and animals. When these RFOs are consumed by animals they cannot be hydrolyzed in monogastric animals due to the absence of alpha-galactosidase activity in their body. Therefore, it would be desirable to reduce these polysaccharides in seeds for easier consumption, while also investigating the impact of oligosaccharide content changes on seed germination and vigor. TILLING has proven to be effective on different agronomic crops such as soybean, maize, rice, wheat, etc. TILLING mutants carrying mutations at the raffinose and stachyose synthase genes may reduce their activity which may impact sucrose content in the seeds without causing unwanted poor agronomic features. Hence, developing high sucrose lines with reduced RFOs for commercial usage will be useful for developing better cross lines for the future and will be healthier and desirable for human and animal consumption. In the current study, we developed an EMS soybean mutagenized population and then TILLING by sequencing was used to study the function of previously discovered raffinose synthase and stachyose synthase genes in the isolated soybean mutants.