不同环境胁迫因子对藻类分子生物学特性的影响研究进展

Research Progress about the Effects of Different Environmental Stress Factors on Algae in Molecular Biology

藻类是水生态系统稳定和生物多样性维持的重要因素,其在生长过程中会受到多种环境因子的胁迫,从而影响正常生命活动。针对不同的藻种(蓝藻、绿藻、硅藻、褐藻等),分析了气象因子(包括UV-B、干旱、高温等)、污染物(重金属、纳米材料、有机污染物、稀土元素等)、水体共存物(水体颗粒物、超标营养盐、H2O2等)3类环境胁迫因子对不同藻种生命活动的影响,并从藻类的抗氧化酶活性变化、细胞超微结构改变、DNA损伤等方面系统综述了不同环境胁迫因子对藻类分子生物学特性的影响。研究表明:藻细胞生长过程中,会形成一套清除ROS的抗氧化防御系统,它可以在藻体受到活性氧攻击时,减轻机体损伤,但当活性氧的产生速度超出抗氧化防御系统的清除能力时,过量的活性氧会对藻体造成氧化胁迫,导致藻细胞蛋白质功能丧失、超微结构受损、DNA损伤与突变,严重时会引起细胞代谢紊乱等,最终抑制藻体的生长发育。研究成果可为进一步系统探究逆境胁迫下藻类的生长状况及其分子生物学特性的变化提供依据。

Algae always plays a key role in stabilizing the balance and the biodiversity of aquatic ecosystem.However,during the growth of algae,the normal life activities are always susceptible to various environmental factors.In this paper,we analyzed the effects of three types of environmental stress factors including meteorological factors(UV-B,drought,high temperature,and etc.),pollutants(heavy metals,nanomaterials,organic pollutants,rare earth elements,and etc.),and water body coexisting matter(water particles,excessive nutrients,H2O2,and etc.)on the life activities of different algae species(Cyanophyta,Chlorophyta,Bacillariophyta and Phaeophyta).The effects of different environmental stress factors on the biological characteristics of algae were systematically reviewed from the changes of antioxidant enzyme activities,cell ultrastructural changes and DNA damage in algae.Results demonstrated that during the growth of algal cells,a set of ROS scavenging antioxidant defense system was formed,which reduced the body damage of algal when attacked by reactive oxygen species;nevertheless,when the production speed of reactive oxygen species exceeded the scavenging ability of antioxidant defense system,excessive reactive oxygen species would cause oxidative stress to the algal body,resulting in the loss of protein function,ultrastructural damage,DNA damage and mutation,and in particular when serious,would cause cell metabolism disorder,and ultimately inhibit the growth and development of algae.The results offer a basis for further study on the growth of algae and the changes of its molecular biological characteristics under stress.