镉胁迫对酵母细胞质膜功能和细胞壁结构的影响  

Effects of cadmium on plasma membrane function and cell wall structure of yeast Saccharomyces cerevisiae

作　　者：孙艳颖 刘瑶 沈裕虎[2] 王桥 黄志伟[1] SUN Yanying;LIU Yao;SHEN Yuhu;WANG Qiao;HUANG Zhiwei(College of Chemical Engineering and Biotechnology,Donghua University,Shanghai,China;Northwest Institute of Plateau Biology,Chinese Academy of Sciences,Qinghai,Xining,China)

机构地区：[1]东华大学生物与医学工程学院,上海 [2]中国科学院西北高原生物研究所,西宁

出　　处：《东华大学学报（自然科学版）》2024年第5期78-84,共7页Journal of Donghua University(Natural Science)

基　　金：国家自然科学基金(32171958);青海省重点研发与转化计划-科技成果转化专项(2023-NK-101)

摘　　要：为了探究重金属镉(Cd)污染的细胞毒性及Cd超富集微生物的选育,以最常用的模式生物酿酒酵母为研究对象,探索了Cd胁迫细胞毒害的靶点及相关基因过表达对细胞抗性的影响。通过基因突变菌株对Cd胁迫生长抑制分析,细胞内活性氧(ROS)和脂质过氧化(MDA)水平的生化检测,探究Cd毒的机制;采用ICP-AES、GC-MS和扫描电子显微镜检测Cd胁迫对细胞内Na/K离子平衡、膜脂组成、细胞壁结构的影响。影响膜脂合成和细胞壁完整性的基因MGA2、PAH1和CHS1突变对Cd敏感,细胞内ROS和MDA水平随Cd处理浓度升高而提高;Cd胁迫破坏细胞Na/K离子平衡,影响细胞脂质代谢,棕榈酸升高、油酸降低;细胞壁的破损率增加,过表达几丁质合成关键基因CHS2有利于维护细胞壁的完整性、提高细胞对Cd的抗性。细胞质膜和细胞壁是Cd胁迫最重要的靶点,为Cd污染的生物治理提供理论基础。To explore the cytotoxicity of heavy metal cadmium(Cd)pollution and the breeding of Cd hyperaccumulation microorganisms,the model organism Saccharomyces cerevisiae was used as the cell model to investigate the target of cytotoxicity caused by Cd stress and the effect of overexpression of related genes on cell resistance.The mechanism of Cd toxicity was explored by analyzing the growth inhibition of mutant strains,the measurement of intracellular reactive oxygen species(ROS),and lipid peroxidation(MDA)levels under Cd stress.The effects of Cd on intracellular Na/K ion balance,membrane lipid composition,and cell wall structure were detected using ICP-AES,GC-MS,and scanning electron microscopy.The mutations in genes MGA2,PAH1,and CHS1 that affect membrane lipid synthesis and cell wall integrity were sensitive to Cd,and the levels of intracellular ROS and MDA increased with the increase of Cd concentration.Cd stress disrupted cell Na/K ion balance,affected cell lipid metabolism,increased palmitic acid and decreased oleic acid,and raised the rate of cell wall damage.Overexpression of the critical gene CHS2 for chitin synthesis was beneficial for maintaining the integrity of the cell wall,thus improving cell resistance to Cd.The plasma membrane and cell wall are the most crucial targets of Cd stress.The results provide a theoretical basis for the biological management of Cd pollution.

关 键 词：镉胁迫 重金属污染 酿酒酵母 细胞膜 细胞壁 

分 类 号：R34[医药卫生—基础医学]