To provide a theoretical basis for the breeding of salt-tolerant germplasm resources in Bothriochloa ischaemum， this experiment investigated the effects of ascorbic acid （AsA） priming on the AsA-GSH cycle in the embryonic mitochondria of B. ischaemum under salt stress. Seeds of ‘Taihang’ B. ischaemum were used as experimental materials， and were primed with 0.1 mmol·L^-1 AsA solution for 12 h， then were germinated in NaCl and Na₂SO₄ solutions containing 30 mmol·L^-1 Na⁺. The changes in AsA-GSH cycle enzymes activities and lipid peroxidation levels in their mitochondria of radicle and plumule were analyzed. The results showed that the activities of catalase （CAT）， glutathione transferase （GST）， dehydroascorbate reductase （DHAR） and monodehydroascorbate reductase （MDHAR） in the mitochondria of radicle and plumule of B. ischaemum were increased significantly after AsA priming （P<0.05）， while the activities of superoxide dismutase （SOD）， ascorbate peroxidase （APX） and glutathione peroxidases （GPX）， as well as the contents of malondialdehyde （MDA） and H₂O₂， were decreased significantly （P<0.05）. Under salt stress， APX and GPX were the key enzymes regulating salt tolerance of embryonic mitochondria in B. ischaemum， but CAT， MDHAR and DHAR were served as the core regulatory enzymes after AsA priming. The membership function analysis indicated that priming with 0.1 mmol·L^-1 AsA had the best effect on enhancing the activities of mitochondrial AsA-GSH cycle enzymes in the radicle of B. ischaemum under 30 mmol·L^-1 NaCl stress.

Bothriochloa ischaemum  /  Saline stress  /  Ascorbic acid priming  /  Mitochondria  /  AsA-GSH cycle