重金属污染影响植食性昆虫的研究进展

重金属污染是世界各国面临的最为棘手的问题之一,对生态系统和食品安全构成了严重威胁。作为生态系统中食物链和食物网的重要环节,植食性昆虫是环境中重金属迁移、积累的重要媒介,其因重金属污染而受到的影响引起了大家的关注。本文综述了从2007至2018年重金属污染对植食性昆虫影响的研究进展。昆虫受重金属胁迫的研究途径有人工饲料添加、野外田间暴露、“土壤-植物-昆虫”食物链传递以及体外注射等。积累在植食性昆虫体内的过量重金属可导致其存活率、繁殖力和种群增长率降低,生长发育迟缓。重金属污染对植食性昆虫的生理生化毒性包括细胞超微结构破坏和DNA损伤,体内能量物质含量降低,酶活性、基因表达改变等。植食性昆虫会通过重金属硫蛋白、解毒酶活性的诱导等机制抵御重金属的毒害,从而对低浓度、长期重金属暴露产生生态适应性,甚至提高对其他逆境(如农药等)的耐受性。

Review on the effects of heavy metal pollution on herbivorous insects

Heavy metal pollution is one of the thorniest issues in the world, which is a serious threat to ecosystems and food security. As an important link of food chain and food web in the ecosystem, herbivorous insects play important role in the transfer and accumulation of heavy metals. Consequently, more and more attentions have been paid on the potential effects of heavy metal pollution on herbivorous insects. Here, we reviewed the effects of heavy metal pollution on herbivorous insects with literature publshied during 2007 to 2018. Herbivorous insects were exposed to heavy metals pollution via four ways, including insect diets or food added with inorganic heavy metals, field exposure with heavy metals, “soil/substrate-plants-herbivorous insect” food chain and in vitro injection. Excessive accumulation of heavy metals in insect body results in decreased survival rate, reproductive capacity and population growth, the retarded growth and development. Physiological and biochemical toxicity of heavy metal pollution to herbivorous insects included cell ultra-structure destruction and DNA damage, decreased amount of energy materials, and changes in enzymes acti-vity and gene expression levels. However, herbivorous insects can resist heavy metal stress by producing metallothionein and enhancing activity of detoxification enzymes etc., which probably results in their adaptive evolution to heavy metal stress at low intensity or long-term and even improve their tolerance to other stresses (e.g., pesticides).