【摘要】 以海带为材料,研究了活性氧(ROS)在褐藻酸降解菌感染中的产生及其作用。结果表明:①褐藻酸降解菌感染引起海带活性氧的大量产生,且海带No.1活性氧的产生速率始终明显大于海带901(P<0.05)。②在褐藻酸降解菌感染的早期阶段,海带维持着较高的抗氧化能力和对褐藻酸降解菌感染较高的抗性,而且海带的抗感染能力与活性氧产生速率呈一定的正相关性;2个品系相比,海带No.1的抗性又明显大于海带901(P<0.01)。③在褐藻酸降解菌感染的后期,海带的抗氧化能力显著降低,膜脂过氧化和脱酯化伤害作用加剧,同时对褐藻酸降解菌感染的抗性显著降低,海带的抗感染能力与活性氧产生速率呈一定的负相关性,其中海带No.1活性氧的产生速率、膜脂过氧化作用和脱酯化作用都远远高于海带901;相反,海带No.1对褐藻酸降解菌的抗性明显低于海带901(P<0.05)。指示在感染的早期阶段,活性氧的产生在海带抵抗褐藻酸降解菌的感染中起着重要作用;而在后期阶段,活性氧的产生又大大降低了海带对褐藻酸降解菌感染的抗性。海带在感染的早期维持较高水平的抗氧化能力,而在感染的后期抗氧化能力显著下降是活性氧表现出双重作用的重要原因之一。更多还原

【Abstract】 Some of the metabolism production of oxygen and oxygen derivative are converted directly or undirectly by oxygen. Because they all contain oxygen atom and are more lively than oxygen, these compounds are generally called reactive oxygen species. Reactive oxygen species includes free radicals which have oxygen atoms or not. The mechanism of the reaction of reactive oxygen species against infection on higher plant has been studied deeply. According to the research, when the plant was infected by pathogen, it could produce amounts of reactive oxygen to resist the invasion of the pathogen. On the other hand, there were other researches indicating that reactive oxygen could do great harm on plant with the presence of the adverse circumstance stress(high salinity ,disease, low temperature and pollution,et al). As a result, the ability of the anti-infection of the plant decreased and disease appeared because of the invasion of germ. However, these researches on low-grade plant ,such as large algae,has not been reported so far. Our research used the more reactive alginic acid decomposing bacteria, provided by Ecological Laboratory of the Ocean University of China. The original sources of the two Laminaria japonic strains—Seaweed 901 and Rongcheng No.1 (for short: Seaweed No.1) were from seaweed culture factory of Yantai and seaweed culture factory of Rongcheng respectively. Both of them were used in the infective experiments. Every two or three days during the process of infection, biochemistry and physiology indexes were used to analysize the samples and compare the difference of the two Laminaria japonic strains. The experiment was repeated with one test. Dates were the average of the four results. The production and its reaction of reactive oxygen species (ROS) in Laminaria japonica against infection of alginic acid decomposing bacteria were investigated. The results showed as follows: (1) The infection of alginic acid decomposing bacteria resulted in massive production of reactive oxygen species. And the creation velocity of reactive oxygen in Seaweed No.1 was obviously larger than that in Seaweed 901 all the time (P<(0.05).) (2) At early stage of infection by alginic acid decomposing bacteria, the Laminaria japonica showed higher antioxidantive activity and higher resistance against infection, and its resistance against infection had positive relationship with productive rate of reactive oxygen species. The comparison between the two strains showed the resistance of Seaweed No.1 was obviously higher than Seaweed 901(P<0.01). (3) At the later stage of infection by alginic acid decomposing bacteria, the antioxidative activity decreased obviously, and the damage of membrane lipid peroxidation and esterification intensified in Laminaria japonica. Meanwhile, the resistance of Laminaria japonica against infection by alginic acid decomposing bacteria notably declined, and its resistance against infection had negative relationship with productive rate of reactive oxygen species. In Seaweed No.1,the creation velocity of reactive oxygen, peroxidation of membrane grease and de-esterification were much more active than these in Seaweed 901. On the contrary, the Seaweed No.1 had lower anti-infection against alginic acid decomposing bacteria than that of Seaweed 901.更多还原