CAJ | 학술논문

重金属污染是全球面临的亟待解决的生态问题.利用植物对重金属的富集作用来清除环境重金属污染即植物修复已成为重要的环境生物技术之一.这一技术的长远发展有赖于在重金属富集或耐受中起关键作用的基因的克隆和应用.植物络合素是植物体内一类重要的对重金属起螯合作用的多肽,其合成受植物络合素合酶的催化.该文取得了如下研究结果:1)通过原子吸收测定表明,在大蒜(Allium sativum)的根部可以积累3 000mg·kg-1的重金属镉;2)将克隆的大蒜植物络合素合酶基因(AsPCS)置于酵母表达启动子之下,构建酵母表达载体,并将其分别转入了因CUP1和acr3基因缺失而对重金属镉和砷敏感的酵母突变体菌株后,发现来自大蒜的AsPCS基因的表达使酵母CUP1缺失菌株对镉的耐受性提高了4倍,acr3缺失菌株对砷的耐受性提高了两倍;3)表达AsPCS基因酵母的生长模式证实了AsPCS基因的表达是酵母对重金属耐受性提高的原因.这些结果暗示,大蒜植物络合素合酶基因在大蒜对重金属的抗性及大蒜根部对镉的积累中起关键作用,可作为重要的基因元件应用到修复污染的植物基因工程中.
중금속오염시전구면림적극대해결적생태문제.이용식물대중금속적부집작용래청제배경중금속오염즉식물수복이성위중요적배경생물기술지일.저일기술적장원발전유뢰우재중금속부집혹내수중기관건작용적기인적극륭화응용.식물락합소시식물체내일류중요적대중금속기오합작용적다태,기합성수식물락합소합매적최화.해문취득료여하연구결과:1)통과원자흡수측정표명,재대산(Allium sativum)적근부가이적루3 000mg·kg-1적중금속력;2)장극륭적대산식물락합소합매기인(AsPCS)치우효모표체계동자지하,구건효모표체재체,병장기분별전입료인CUP1화acr3기인결실이대중금속력화신민감적효모돌변체균주후,발현래자대산적AsPCS기인적표체사효모CUP1결실균주대력적내수성제고료4배,acr3결실균주대신적내수성제고료량배;3)표체AsPCS기인효모적생장모식증실료AsPCS기인적표체시효모대중금속내수성제고적원인.저사결과암시,대산식물락합소합매기인재대산대중금속적항성급대산근부대력적적루중기관건작용,가작위중요적기인원건응용도수복오염적식물기인공정중.
Remediation of soils contaminated by heavy metals is one of the most pressing environmental prob-lems facing the biosphere. Phytoremediation is a new biotechnique to clean environmental pollutants by plants,including heavy metals. In the long term, major improvements in phytoremediation will rely on the isolationand application of the genes from various plant, bacteria, and animal sources that can enhance metal accumu-lation. Phytochelatin is a type of polypeptide that combines heavy metals in plants, and its synthesis is regulat-ed by phytochelatin synthesase (PC synthase). In this study, we determined that the roots of garlic (Alliumgarlic (AsPCS) was constructed and transferred into heavy metal sensitive yeast mutant cells. The resultsshowed that the expression of AsPCS was improved by 4 folds in yeast cells with cadmium tolerance and a 2folds increase was observed in arsenate tolerant cells as compared to the control cells. Further study about thegrowth patterns of AsPCS-expressed yeast indicated that the expression of AsPCS was critical for yeast heavymetal tolerance. As an important role in the garlic' s response to heavy metal, AsPCS can work as a significantgene tool in the phytoremediation of heavy metal pollution.