Identification and validation of functional markers for the superoxide dismutase gene TaSOD-B2 in common wheat

Superoxide dismutase (SOD) is a significant metalloenzyme that affects the colour and rheological properties of wheat flour. It also enhances the stability of proteins playing a key role in coping with environmental stresses such as high temperatures, drought and salinity. Although SOD plays a crucial role in plant stress tolerance, its molecular mechanisms under various growth environments have not been fully elucidated. In addition, several SOD genes exist in wheat, but the current lack of corresponding molecular markers makes it difficult to effectively select varieties with excellent stress tolerance during breeding. Therefore, in this study, SOD activity in 273 grain sampies from different wheat regions was measured using the nitroblue tetrazolium (NBT) photoreduction assay, and genetic variation at the TaSOD-B2 locus was associated with two co-dominant functional markers .

There were differences in SOD activity in different wheat regions, with the highest activity in the Southwest winter wheat region, followed by the Northern winter wheat region, the Huanghuai winter wheat region, Foreign varieties, and the Middle and lower reaches of the Yangtze River winter wheat region. In the Foreign varieties and the Huanghuai winter wheat region, the SOD activities of materials containing TaSOD-B2b allelic variants were significantly higher than those of materials containing TaSOD-B2a allelic variants, indicating that TaSOD-B2b is the superior allelic variant type.

The functional marker SOD2B1/SOD2B2 was effective in distinguishing varieties with different SOD activity levels. Therefore, SOD2B1/SOD2B2 can be applied to molecular marker-assisted breeding in wheat.