Arbuscular mycorrhiza fungus improved growth, antioxidant defense, and endogenous hormones in tall fescue under low-light stress

Abstract Low light is one of the most common stress factors affecting turfgrass growth. In this study, we investigated the effects of arbuscular mycorrhizal fungus (AMF) on oxidative damage caused by low-light (LL) stress in tall fescue (Festuca arundinacea Schreb.). Plant growth was inhibited by LL due to the accumulation of reactive oxygen species (ROS), including superoxide anions and hydrogen peroxide, which led to lipid peroxidation of membranes. However, AMF inoculation significantly improved the growth of tall fescue. This can be attributed to the high activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX), as well as the high proline content. In addition, AMF inoculated plants had a high chlorophyll content and high H+-ATPase activity. Moreover, AMF inoculated plants showed high levels of gibberellic acid (GA) and abscisic acid (ABA). These results suggested that AMF could develop LL stress tolerance through enzymatic antioxidants and improve plant growth due to high H+-ATPase activity and high GA and ABA levels.