Physiological Changes,Protein And Related Antioxidant Gene Expression Responses Of Avena Sativa L.Seed Under Different Aging Treatment

To explore the key factors of seed deterioration, understand the deterioration process and the deterioration mechanism, Oat seeds were stored under different moisture content in room tempreture and4℃for6to18months and45℃,48h. We measured the germination rate, malondialdehyde, superoxide anion production rate, catalase, superoxide dismutase, ascorbate peroxidase activity and other physiological, protein and antioxidant gene expression, those were important theoretical significance to provide the high vigor seeds for the actual production and enhance the storage of seeds. The main results as follow:Oat seeds could maintain high vigor at4%and10%moisture content when they were stored at room temperature less than6months or at low temperature at least18months. Oat seeds could maintain high vigor at16%and22%moisture content when they were stored less than6months at low and room temperature.At4%～16%moisture content, the superoxide anion production rate was lower at low temperature than at room temperature, but it was higher at low temperature than at room temperature at22%and28%moisture content. Hydrogen peroxide content was higher at low temperature than at room temperature at4%～16%moisture content, it was lower at low temperature than at room temperature at22%and28%. It indicated that ROS exist in different forms at different temperature, it was a turning point at16%moisture content.In oat seed storage, proline played the main role in adaptation to oxidative stress in seeds with higher moisture content, while antioxidant enzymes (SOD, CAT, and APX) played the main roles in seeds with lower moisture content at low temperature. There was different changing tendency between CAT and APX activity with moisture content increasing and storage duration prolonged. CAT activity was more responsive to the variation in higher moisture content compared to APX, APX was more responsive than CAT to oxidative damage as the storage duration extended. These two enzymes may have complementary or interactin roles.In oat seed aging treatment, SOD1was not the main enzyme contributing to total SOD activity, but APX1and CAT1were consistent with APX and CAT activities. When oat seeds are moderate aging, P5CS1and PDH1can adjust the proline content to combat aging and promote the SOD1, CAT1and APX1expression. PDH1reduce to protect the seeds.After LC-MS/MS, at28%moisture content,22polypeptides had identification at70KDa, these proteins including in energy metabolism, amino acid metabolism and translation;5polypeptides had identification at35KDa, these proteins including in energy metabolism, redox and translation;6polypeptides had identification at25KDa, these proteins including1up-regulated and5down-regulated protein.At28%moisture content, MDA content increased and BADH down-regulated, it showed BADH was consistent with MDA;7proteins changes in TCA cycle was consistent with RGT, OMR and IMT changes in respiration.