当前位置: X-MOL 学术Aquat. Toxicol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Functional and mechanistic insights into the differential effect of the toxicant ‘Se(IV)’ in the cyanobacterium Anabaena PCC 7120
Aquatic Toxicology ( IF 4.5 ) Pub Date : 2021-04-18 , DOI: 10.1016/j.aquatox.2021.105839
Manisha Banerjee 1 , Prakash Kalwani 1 , Dhiman Chakravarty 1 , Beena Singh 2 , Anand Ballal 1
Affiliation  

Selenium, an essential trace element for animals, poses a threat to all forms of life above a threshold concentration. The ubiquitously present cyanobacteria, a major photosynthetic biotic component of aquatic and other ecosystems, are excellent systems to study the effects of environmental toxicants. The molecular changes that led to beneficial or detrimental effects in response to different doses of selenium oxyanion Se(IV) were analyzed in the filamentous cyanobacterium Anabaena PCC 7120. This organism showed no inhibition in growth up to 15 mg/L sodium selenite, but above this dose i.e. 20–100 mg/L of Se(IV), both growth and photosynthesis were substantially inhibited. Along with the increased accumulation of non-protein thiols, a consistent reduction in levels of ROS was observed at 10 mg/mL dose of Se(IV). High dose of Se(IV) (above 20 mg/L) enhanced endogenous reactive oxygen species (ROS)/lipid peroxidation, and decreased photosynthetic capability. Treatment with 100 mg/L Se(IV) downregulated transcription of several photosynthesis pathways-related genes such as those encoding photosystem I and II proteins, phycobilisome rod-core linker protein, phycocyanobilin, phycoerythrocyanin-associated proteins etc. Interestingly, at a dose range of 10-15 mg/L Se(IV), Anabaena showed an increase in PSII photosynthetic yield and electron transport rate (at PSII), suggesting improved photosynthesis. Se was incorporated into the Anabaena cells, and Se-enriched thylakoid membranes showed higher redox conductivity than the thylakoid membranes from untreated cells. Overall, the data supports that modulation of photosynthetic machinery is one of the crucial mechanisms responsible for the dose-dependent contrasting effect of Se(IV) observed in Anabaena.



中文翻译:

从功能和机理上了解毒物“ Se(IV)”在蓝细菌鱼腥藻PCC 7120中的差异作用

硒是动物必需的微量元素,它对超过阈值浓度的所有生命形式都构成威胁。普遍存在的蓝细菌是水生和其他生态系统的主要光合作用生物成分,是研究环境毒物影响的出色系统。在丝状蓝细菌鱼腥藻中分析了响应于不同剂量的硒氧阴离子Se(IV)导致有益或有害作用的分子变化。PCC7120。高达15 mg / L的亚硒酸钠对这种生物没有生长抑制作用,但高于此剂量,即20-100 mg / L的Se(IV),则生长和光合作用都受到了抑制。随着非蛋白质硫醇积累的增加,在10 mg / mL的Se(IV)剂量下观察到ROS水平的持续降低。高剂量的Se(IV)(高于20 mg / L)可增强内源性活性氧(ROS)/脂质过氧化作用,并降低光合能力。用100 mg / L Se(IV)处理可下调几种与光合作用相关的基因的转录,例如编码光系统I和II蛋白,藻胆杆核心接头蛋白,藻蓝蛋白,藻红蛋白相关蛋白等的基因。有趣的是,在一定剂量范围内10-15 mg / L Se(IV),鱼腥藻表明PSII的光合产量和电子传输速率增加(在PSII处),表明光合作用得到改善。硒被整合到Anabaena细胞中,富硒类囊体膜的氧化还原电导率高于未处理细胞的类囊体膜。总体而言,数据支持光合作用机制的调节是导致在鱼腥藻中观察到的Se(IV)剂量依赖性对比作用的关键机制之一。

更新日期:2021-05-18
down
wechat
bug