Unravelling the long-term beneficial effects of stress priming-induced tolerance to waterlogging stress in wheat

This study aimed to explore the effects of waterlogging priming during the seedling stage on waterlogging tolerance in wheat at the booting stage. Greenhouse pot experiments were conducted for two consecutive years on two wheat cultivars with different response types to waterlogging priming throughout their entire growth period using four treatments: no priming and no waterlogging stress (NC), priming and no waterlogging stress (PC), no priming with waterlogging stress (NW), and priming with waterlogging stress (PW). Through an investigation of the yield, biomass, aboveground photosynthesis, root morphological structure and physiological indices, we confirmed that the effectiveness of waterlogging priming varied by cultivars. For Zhenmai10, seedling-stage waterlogging priming significantly alleviated the yield loss caused by waterlogging at the booting stage. The aboveground photosynthetic efficiency and root growth were maintained. Antioxidant system was further activated to regulate reactive oxygen species homeostasis. The anaerobic respiration process and aerenchyma formation were promoted to improve oxygen supply capacity. However, all these effects appeared to be weak in Yangmai22. Generally, we offered a new perspective on physiological mechanisms of the long-term effects of waterlogging priming from two aspects: enhancing waterlogging tolerance of plants and accelerating the physiological response of roots to waterlogging stress.