Assessment of seed storage protein composition of six Iranian adoptedsoybean cultivars [Glycine max (L.) Merrill.]

Seed protein quality is an important topic in the production of soybean. The quality of soybean proteins islimited by anti-nutrient proteins and low levels of essential sulfur amino acids. In this study, protein contentand solubility of six cultivars were evaluated and seed storage proteins were analyzed using SDS-PAGE andscanning densitometry. The results showed that seed storage protein bands were similar among soybeancultivars. However, concentration of β-conglycinin (7S), glycinin (11S) proteins and related subunits werestatistically different among the soybean cultivars. According to the results of this study, 033 and DPXcultivars were characterized by high levels of protein content (42.45 %) and protein solubility (76.58 mg g-1)respectively. Two cultivars DPX and JK were also identified by high 11S/7S ratio (1.39 and 1.43 %respectively). Besides, the JK was considered by the lowest concentration of 7S protein (20.35 %). The resultsshowed that a significant negative correlation existed between protein content and solubility (r= -0.66). Asignificant and moderate positive correlation was found between acidic and basic subunits with 11S protein(r= 0.72 and 0.47 respectively). The 11S and 7S proteins also showed positive and negative correlation with11S/7S ratio (r= 0.70 and -0.85 respectively). On the other hand, acidic subunits were characterized bysignificant positive and negative relationship with 11S/7S ratio and some anti-nutrients protein respectively.Thereupon, these results suggested that the development of new genotypes of soybean with high level ofacidic subunits of 11S protein can be notable in increasing seed storage protein quality in soybean breedingprograms.

Keywords:

Soybean , Seed storage proteins , β-conglycinin , Glycinin , Anti-nutrient proteins