Effects of Abscisic Acid and Its Biosynthesis Inhibitor on the Activities of Antioxidant System of Sugarcanes Treated by Cold Stress

The sugarcane variety GT28 was employed as materials in this experiment. The young seedlings were sprayed with abscisic acid (ABA) and its biosynthesis inhibitor, sodium tungstate, before 12 h of cold treatment. Leaf +1 and tender root samples were taken at different stages of cold treatment. Malondialdehyde (MDA) contents, active oxygen species (ROS) levels and the activities of antioxidant enzymes were determined during cold stress. The results showed that the activities of antioxidant enzymes increased under cold stress. After ABA application, the content of ABA and the activities of superoxide dismutase (SOD), ascorbic peroxidase (APX), catalase (CAT), peroxidase (POD) and glutathione reductase (GR) increased, while the contents of superoxide anion (O₂^-·), H₂O₂ and MDA decreased in sugarcane seedlings. But when treated by sodium tungstate application, the results were quite the contrary. It can be concluded that ABA and its biosynthesis inhibitor have an important regulatory role in the antioxidant protection system in sugarcane seedlings under cold stress. The cold resistance in sugarcane enhanced by ABA application under cold stress may be associated with the induction of antioxidant protection system.