Effect of a mutation in Raffinose Synthase 2 (GmRS2 ) on soybean quality traits

Abstract

The presence of stachyose and raffinose is considered an antinutritional factor for humans and monogastric animals, leading to limitations on soybean consumption as a protein source. In the present study, the effect of a mutation in the raffinose synthase 2 gene was measured on soybean quality traits. We used an F 2 population with 168 soybean individuals developed by crossing four soybean lines and evaluated oil, protein, sucrose, raffinose, stachyose and fatty acid contents and their relationships. The mutation explained 69.61%, 51.81% and 31.96% of stachyose, raffinose and sucrose variation, respectively, and we were able to produce soybean with average stachyose of 0.18%. The low coefficients of determination for protein and oil indicate that the mutation can be used to increase sucrose and reduce raffinose and stachyose content without major changes in oil and protein.

Characterization of raffinose metabolism genes uncovers a wild Arachis galactinol synthase conferring tolerance to abiotic stresses

“…It is worth noting, however, that the natural accumulation of RFOs in mature seeds to protect the embryo from desiccation is considered an antinutritional factor for many grain legumes 13 , 17 . Thus, the reduction of RFO content, or even their removal, to improve digestibility and nutritional quality of seeds, has been the focus of many legume breeding programs 16 . It includes the development of transgenic plants by the antisense/RNAi suppression of RFO-synthesizing genes or by the overexpression of RFO-degrading genes 69 .…”

“…Whilst RFOs are major soluble sugars that are second only to sucrose in abundance in mature legume seeds 13 , very little is known about the genes involved in raffinose metabolism in Fabaceae species, with few examples described in Cicer arietinum and Glycine max 14 , 15 . RFOs are indeed antinutritional and undesirable compounds of legume seeds and the development of cultivars with reduced levels of raffinose and stachyose has been the focus of breeding programs for improving nutritional quality in many grain legumes 13 , 16 , 17 . In peanut ( Arachis hypogaea ), the second most cultivated grain legume in the world after soybean, seeds also accumulate high amounts of indigestible RFOs, which limits its consumption 13 , 17 .…”