不同海带品系抗氧化系统活性与耐热性的相关性研究

以山东沿海广泛培育的两个海带品系耐高温海带901(简称901)和热敏感海带荣成1号(简称RC)为实验材料,研究不同温度条件下其抗氧化系统活性与耐热性状的相关性.结果表明,常温条件下(10℃)901与RC抗氧化系统的基础活性与耐热性状间无显著相关.高温胁迫条件下(18℃)RC体内的活性氧(reactive oxygen species,ROS)含量快速升高,而901的ROS在整个胁迫过程中变化不大,说明ROS可能对高温氧化胁迫具有重要意义.RC的抗氧化系统对高温胁迫比901敏感,表现为出现活性有效抑制的时间和幅度都强于901.超氧化物歧化酶、谷胱甘肽过氧化物酶和抗坏血酸和维生素E可能在保护海带细胞免受高温胁迫方面具有重要作用.901的叶绿素对高温胁迫的响应明显滞后于RC,叶绿素含量的半伤害时间可作为判定幼苗期901和RC耐热性的灵敏指标.导致不同品系海带耐热性差异的并非其抗氧化系统基础活性的高低,而是该系统对高温胁迫的应激性和敏感性差异.

Relationships between antioxidant activities and heat-resistant features of two Laminaria japonica strains

The study on the relationships between antioxidant activities and heat-resistant features of two Laminaria japonica gametophyte mutants Kelp 901(abbreviated as 901)and Rongcheng No.1(abbreviated as RC)under different temperature conditions showed that under normal temperature condition(10 ),there were no positive relationships between the basal antioxidant activities and heat-resistant features of 901 and RC,while under heat stress(18 ),the reactive oxygen species(ROS)contents kept constant in 901,but accumulated rapidly in RC,suggesting that ROS played an essential role in oxidative stress.The enzyme activities in RC were more vulnerable to high temperature,and its antioxidant enzyme activities decreased more sharply under heat stress.Ascorbic acid(ASA),vitamin E,superoxide dismutase(SOD)and glutathione peroxidase(Gpx)might play important roles in kelp's heat-resistance.Chlorophyll a was sensitive to heat stress,and its 50% nocuity time could be used as an indicator to distinguish kelp strains with different heat-resistance.It was suggested that the antioxidant system's responses to heat stress instead of its basic activities accounted for the kelp's heat-resistance.