Auxin Participates in the Regulation of the Antioxidant System in Malus baccata Borkh. Roots under Sub-Low Temperature by Exogenous Sucrose Application

Malus baccata Borkh., an apple rootstock, is found to be damaged by oxidation at sub-low root-zone temperature. In previous studies, we have that exogenous sucrose could alleviate oxidative damage and increase the indole acetic acid (IAA) in roots under temperature (L). However, role of IAA sucrose-induced tolerance L remains unclear. A pot experiment was conducted evaluate effects synthesis/transport inhibitors (2,3,5-triiodobenzoic acid, TIBA; 4-biphenylboronic BBo) on growth, levels, sugars, antioxidant system M. L. The results showed treatment decreased contents 23.69% (48 h) induced significant increases root malondialdehyde (MDA) reactive oxygen (ROS), along with increasing catalase (CAT), ascorbate peroxidase (APX), glucose-6-phosphate dehydrogenase (G6PDH) activities, while superoxide dismutase (SOD) monodehydroascorbate reductase (MDHAR) activities first increased (24 then h), glutathione (GR) (POD) significantly decreased. also ascorbate/oxidized (AsA/DHA), glutathione/oxidized (GSH/GSSG), coenzyme II/oxidized II (NADPH/NADP+) ratios. Furthermore, sucrose, fructose, glucose sorbitol suppressed plant growth. Sucrose pretreatment (12.42%, 24 h 14.44%, 48 MDA ROS contents, which improved enzymes other than APX AsA, GSH, NADPH, promoted + TIBA or BBo treatments attenuated almost abolished positive Our findings indicate involved regulation provided theoretical references for further study adaptability low