Pyropia yezoensis (P. yezoensis) is an intertidal alga that periodically experiences environmental stress with turning tides. Both the antioxidases and the antioxidants are involved in the acclimation to the extremely variable intertidal environments. Here, mild (50‰), moderate (90‰), and severe (120‰) high-salinity stress treatments were designed to investigate protective mechanisms against reactive oxygen species (ROS). Results showed that hydrogen peroxide (H₂O₂) content in high-salinity stressed samples was maintained at levels similar to or lower than that of the control. Superoxide dismutase (SOD) activity was up-regulated in samples treated with severe high-salinity and sustained stress with moderate high-salinity. Catalase (CAT) activity increased at the start of the experiment but decreased after 2 h of stress treatment. Reduced ascorbate (AsA) was up-regulated under high-salinity conditions, and AsA-dependent antioxidant enzymes played a more important role in the mild and moderate high-salinity stress treatments. While, reduced glutathione (GSH)-mediated antioxidant reactions became the most important as salinity increased to 120‰. Moreover, the rapid glutathione up-regulation during the initial stage of stress treatments demonstrated that GSH is essential in the scavenging of instantaneous ROS bursts. GSH was also suggested to be a central intermediate molecule involved in multiple oxidative stress response pathways. The results obtained here will do benefits to the breeding of P. yezoensis.

yezoensis（P. yezoensis）是一种潮间带藻类，在潮汐作用下会周期性地遭受环境压力。抗氧化酶和抗氧化剂都参与了潮间变化很大的环境的适应。在此，设计了轻度（50‰），中度（90‰）和重度（120‰）高盐度胁迫处理，以研究针对活性氧（ROS）的保护机制。结果表明，过氧化氢（H ₂ O ₂高盐度胁迫样品中的含量保持在与对照相似或更低的水平。在严重的高盐度和持续的压力以及中等的高盐度下处理的样品中，超氧化物歧化酶（SOD）活性上调。过氧化氢酶（CAT）活性在实验开始时增加，但在应激处理2小时后下降。在高盐度条件下，减少的抗坏血酸（AsA）上调，而AsA依赖性抗氧化酶在轻度和中度高盐度胁迫治疗中起着更重要的作用。同时，随着盐度增加到120‰，还原型谷胱甘肽（GSH）介导的抗氧化剂反应变得最重要。此外，应激治疗初期谷胱甘肽快速上调表明，GSH在清除瞬时ROS爆发中至关重要。GSH还被认为是参与多个氧化应激反应途径的中央中间分子。这里获得的结果将有利于玉米的育种条斑紫菜。