小球藻(Chlorella vulgaris)对泰乐菌素的胁迫响应与耐受性  

Stress response and tolerance of Chlorella vulgaris to tylosin

作　　者：聂红丽 成琪璐 孙万春[2] 马进川 林辉[2] 马军伟[2] NIE Hongli;CHENG Qilu;SUN Wanchun;MA Jinchuan;LIN Hui;MA Junwei(School of Environment and Resources,Zhejiang A&F University,Hangzhou 311300,China;State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products,Institute of Environment,Resources,Soil and Fertilizer,Zhejiang Academy of Agricultural Sciences,Hangzhou 310021,China)

机构地区：[1]浙江农林大学环境与资源学院,浙江杭州311300 [2]浙江省农业科学院省部共建农产品质量安全危害因子与风险防控国家重点实验室,环境资源与土壤肥料研究所,浙江杭州310021

出　　处：《浙江农业学报》2024年第10期2316-2327,共12页Acta Agriculturae Zhejiangensis

基　　金：国家自然科学基金(42207285);浙江省科技创新领军人才项目(2021R52045)。

摘　　要：抗生素是一类典型的新兴污染物,对水生生物有较高的生态风险。微藻作为自然水体的初级生产者,极易受到环境变化尤其是污染物暴露的影响。但是目前关于微藻对泰乐菌素(tylosin, TYN)胁迫的响应研究还十分有限。本研究选用模式藻种小球藻(Chlorella vulgaris)为试验材料,从细胞生长、生理、代谢、基因表达等层面研究TYN处理下微藻的胁迫耐受性。结果表明,TYN对C.vulgaris的生长呈典型的hormesis效应:即低质量浓度(≤0.5 mg·L^(-1))促进藻的生长;随着TYN处理浓度的升高,其对C.vulgaris生长的抑制作用越明显,并导致细胞形态改变、质壁分离、类囊体降解等不同程度的氧化损伤。转录组测序发现,高质量浓度TYN处理8 d后,C.vulgaris中光合作用、核糖体生物合成、抗氧化等相关的基因表达水平显著下调,进一步表明高质量浓度TYN对微藻细胞有抑制效应。值得注意的是,C.vulgaris可通过增加胞外多糖和蛋白质含量提高TYN与胞外聚合物中-OH、-COOH、-NH等官能团的结合水平,以应对高质量浓度TYN对细胞的胁迫效应。研究系统揭示了C.vulgaris对TYN的胁迫响应与耐受性,相关结果可以为抗生素的水体生态风险评估提供参考依据。Antibiotics are typical emerging pollutants with high ecological risk to aquatic organisms.As the primary producers of natural water,microalgae are highly susceptible to environmental changes,especially exposure to pollutants.However,the studies on the response of microalgae to tylosin(TYN)stress are still limited.In this study,Chlorella vulgaris,a model algae species,was selected as the experimental material to investigate the stress tolerance of microalgae exposed to TYN from the aspects of microalgal growth,physiology,metabolism,and gene expression.The results showed that TYN had a typical hormesis effect on the growth of C.vulgaris.Microalgal growth was promoted by low concentration of TYN(≤0.5 mg·L^(-1)),with the increase of TYN exposure concentration,its inhibitory effect on the growth of C.vulgaris was more obvious,and it led to different degrees of oxidative damage such as cell morphological changes,plasmolysis,and thylakoid degradation.Transcriptome sequencing showed that the expression levels of genes related to photosynthesis,ribosome biosynthesis,and antioxidant in C.vulgaris were significantly down-regulated after 8 days of high-concentration TYN treatment,further indicating that high-concentration TYN had an inhibitory effect on C.vulgaris cells.It was worth noting that C.vulgaris could improve the binding level of TYN to functional groups such as—OH,—COOH and—NH in extracellular polymeric substance by increasing the content of extracellular polysaccharides and proteins,so as to cope with the stress effect of high concentration TYN on cells.This study systematically revealed the stress responses and tolerance of C.vulgaris to TYN,and the relevant results provided a reference for the ecological risk assessment of antibiotics in water.

关 键 词：新兴污染物 微藻 胁迫响应 转录组学分析 胞外聚合物 逆境耐受 

分 类 号：S184[农业科学—农业基础科学]