Overexpression of NtIPMS reduces tobacco seed germination under cold stress by influencing amino acids and reactive oxygen species

Cold tolerance at the seed germination stage is a critical trait for tobacco production. However, the mechanism of seed germination under cold stress is largely unknown in tobacco. In this study, we revealed that tobacco isopropylmalate synthase gene NtIPMS negatively regulates seed germination under cold stress. Compared with wild-type (WT) of tobacco, the seed germination and seedling establishment were significantly reduced in overexpressing NtIPMS lines under cold stress. Physiological assays showed that NtIPMS regulates seed germination by influencing the levels of amino acids and reactive oxygen species (ROS) under cold stress. The lower accumulation of stress-associated amino acids and ROS were observed in overexpression NtIPMS line compared with WT under cold stress. The exogenous application of amino acids and hydrogen peroxide (H2O2) may be an effective way to enhance seed germination under cold stress in tobacco.