Waterlogging severely restricts wheat seed germination and seedling growth, but the underlying tolerance mechanisms remain poorly understood. Using two tolerant (T1, T2) and two sensitive (S1, S2) wheat genotypes, we analyzed phenotypic, physiological, metabolic and transcriptional responses to waterlogging stress. Tolerant genotypes maintained high seed viability and germination rate and showed accelerated seedling growth after waterlogging, whereas sensitive genotypes suffered severe germination inhibition and loss of embryo viability. Tolerant genotypes exhibited more stable antioxidant enzyme activities and glutathione content, which alleviated hypoxia-induced oxidative damage. Integrated omics revealed tissue-specific adaptive strategies: shoots activated glutathione metabolism and primary carbon metabolism to maintain redox balance and energy supply, whereas roots enhanced secondary metabolism, such as flavonoid biosynthesis, for stress defense. Conserved pathways, including lysine degradation and phenylpropanoid metabolism, contributed to antioxidant capacity, cell wall reinforcement and immune priming. Stress memory also promoted rapid recovery during reoxygenation. In contrast, sensitive genotypes lacked such coordinated responses and suffered irreversible damage. This study clarifies the multi-level mechanisms of waterlogging tolerance and provides potential targets for breeding waterlogging-resistant wheat.
Zheng Wang, Yuling Zheng, Ling-Zhen Ye et al.· Plant physiology and biochem...· 0 citations
Waterlogging is a major abiotic stress that restricts global wheat production. Although adventitious root formation and aerenchyma development are key adaptive strategies to waterlogging, the spatial mechanisms underlying root adaptation remain unclear. Here, we systematically analyzed the anatomical, physiological, and metabolic responses in the basal (RB), middle (RM), and tip (RT) regions of wheat adventitious roots under different waterlogging durations. Aerenchyma formation was most pronounced in the root middle, which also exhibited the highest levels of reactive oxygen species (ROS) and antioxidant enzyme activities. Phytohormone profiling revealed distinct spatial regulation: ethylene levels increased steadily and localized mainly in the root tip, while abscisic acid, gibberellins, and jasmonic acid accumulated predominantly in the basal and middle, peaking at 24 h of waterlogging. Metabolomic and spatial imaging analyses revealed that prolonged waterlogging induced increases in metabolites related to carbon/energy metabolism and antioxidant defense, and promoted the tissue-specific accumulation of non-enzymatic antioxidants (e.g., glutathione and ascorbate) around the endodermis region and root tip. In conclusion, these findings revealed that wheat adventitious roots employ a coordinated, region-specific strategy of integrating enzymatic antioxidant defense, aerenchyma development, hormonal signaling, and spatially compartmentalized metabolites to develop waterlogging tolerance.
Yu-Mei Wu, Ya-Nan Niu, Danyin Huang et al.· Plant physiology and biochem...· 0 citations
