热锻炼对龙须菜高温胁迫响应的影响

夏季高温是限制龙须菜(Gracilariopsis lemaneiformis)生长和发育的一个主要问题。本研究以野生龙须菜作为材料,经过28℃的热锻炼预处理72 h,再分别置于32、36、40℃高温胁迫24 h,并测定了高温胁迫条件下龙须菜的丙二醛(MDA)、过氧化氢(H2O2)和可溶性蛋白质的含量,以及超氧化物歧化酶(SOD)活性和抗坏血酸(AsA)水平等生理指标,研究了龙须菜对高温胁迫的响应。结果表明:热锻炼能维持藻体较低的MDA含量,降低H2O2的产生速率,缓解藻体的膜脂过氧化伤害;同时热锻炼缓解了可溶性蛋白质的降解,增加了SOD酶的比活力,缓解了AsA的下降速率,说明热锻炼能缓解高温胁迫对藻体的伤害,有效地提高了龙须菜对高温胁迫响应的能力。

Effects of heat acclimation on high temperature stress response of Gracilariopsis lemaneiformis

High temperatures in summer are a major problem in the growth and development of Gracilariopsis lemaneiformis. In this study, the wild-type G. lemaneiformis was used as material. After heat acclimation pretreatment at 28°C for 72 h, the algae were placed under conditions of high temperature stress of 32, 36, and 40°C for 24 h. The physiological indices such as MDA, hydrogen peroxide (H₂O₂) and soluble protein content, superoxide dismutase (SOD) activity, and ascorbic acid (ASA) content in G. lemaneiformis were measured under conditions of high temperature stress to assess the effects of high-temperature stress response of G. lemaneiformis. The results revealed that heat acclimation can maintain low MDA levels, reduce the production rate of active oxygen species (H₂O₂), and alleviate the damage of cell membrane lipid peroxidation. Furthermore, heat acclimation alleviated the degradation of soluble proteins, improved the specific activity of SOD, and relieved the declining AsA rate, indicating that heat acclimation can amend the harm of high temperatures in the algae and can improve the capacity of G. lemaneiformis to respond to high temperature stress.