Seed priming with selenite enhances germination and seedling growth of Sorghum [Sorghum bicolor (L.) Moench] under salt stress

Justify that the use of selenium has been shown to promote seed germination and seedling growth of some crops under salt stress but the physiological mechanisms in sorghum remain poorly understood. Herein, grain sorghum [Sorghum bicolor (L.) Moench] variety Jinza 2002 was used to explore the effects and mechanisms of seed priming with 25 μmol/L sodium selenite [Se(IV)] on seed germination, seedling growth, antioxidant enzyme activity and osmotic regulatory substances under 120 mmol/L NaCl. The results showed that soaking sorghum seeds in Se(IV) effectively alleviated the harm of salt stress. Compared with the Na group, Se(IV) application increased germination percentage (by 23.8%), while facilitating the elongation of radicles (by 4.2%) and plumules (by 18.4%) under salt stress. Salt-stressed seedlings showed increased levels of leaf chlorophyll, soluble sugar, soluble protein and proline contents, and antioxidant enzyme activities, as well as root activity, and total biomass following Se(IV) application, along with decreased relative electrical conductivity and malondialdehyde content in the leaves. Findings of this study indicate that seed priming with Se(IV) facilitates sorghum seed germination and seedling growth under salt stress by improving root activity, enhancing leaf photosynthesis and antioxidant responses, and reducing cell membrane damage.