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Wang C, Zhang H, Wang J, Sprecher B, Lin S. Glyphosate (Roundup) as phosphorus nutrient enhances carbon and nitrogen accumulation and up-regulates phosphorus metabolisms in the haptophyte Isochrysis galbana. Sci Total Environ 2024; 913:169715. [PMID: 38160825 DOI: 10.1016/j.scitotenv.2023.169715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 12/24/2023] [Accepted: 12/25/2023] [Indexed: 01/03/2024]
Abstract
Inorganic phosphate limitation for phytoplankton may be intensified with water stratification by global warming, and with the increasing nitrogen: phosphorus (N:P) ratio in coastal zones resulting from continuous anthropogenic N overloading. Under these circumstances, phytoplankton's ability to use dissolved organic phosphorus (DOP) will give species a competitive advantage. In our previous study, we have shown that the haptophyte Isochrysis galbana can use glyphosate (Roundup) as a P nutrient source to support growth, but the mechanism of how remains unexplored. Here, we show that three genes encoding PhnC (IgPhnCs), which exhibit up-regulated expression in glyphosate-grown cultures, are probably responsible for glyphosate uptake, while homologs of PhnK and PhnL (IgPhnK and IgPhnL) probably provide auxiliary support for the intracellular degradation of glyphosate. Meanwhile, we found the use efficiency of glyphosate was low compared with phosphate, probably because glyphosate uptake and hydrolysis cost energy and because glyphosate induces oxidative stress in I. galbana. Meanwhile, genes encoding 5-enolpyruvylshikimate 3-phosphate (EPSP) synthase, the target of the herbicide, were up-regulated in glyphosate cultures. Furthermore, our data showed the up-regulation of P metabolisms (transcription) in glyphosate-grown cultures, which further induced the up-regulation of nitrate/nitrite transport and biosynthesis of some amino acids. Meanwhile, glyphosate-grown cells accumulated more C and N, resulting in remarkably high C:N:P ratio, and this, along with the up-regulated P metabolisms, was under transcriptional and epigenetic regulation. This study sheds lights on the mechanism of glyphosate utilization as a source of P nutrient by I. galbana, and these findings have biogeochemical implications.
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Affiliation(s)
- Cong Wang
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Huan Zhang
- Department of Marine Sciences, University of Connecticut, Groton, CT, United States of America
| | - Jingtian Wang
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Brittany Sprecher
- Department of Marine Sciences, University of Connecticut, Groton, CT, United States of America
| | - Senjie Lin
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China; Department of Marine Sciences, University of Connecticut, Groton, CT, United States of America.
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Zhang H, Zheng Y, Wang XC, Wang Y, Dzakpasu M. Characterization and biogeochemical implications of dissolved organic matter in aquatic environments. J Environ Manage 2021; 294:113041. [PMID: 34126535 DOI: 10.1016/j.jenvman.2021.113041] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 05/12/2021] [Accepted: 06/06/2021] [Indexed: 06/12/2023]
Abstract
Dissolved organic matter (DOM) is viewed as one of the most chemically active organic substances on earth. It plays vital roles in the fate, bioavailability and toxicity of aquatic exogenous chemical species (e.g., heavy metals, organic pollutants, and nanomaterials). The characteristics of DOM such low concentrations, salt interference and complexity in aquatic environments and limitations of pretreatment for sample preparation and application of characterization techniques severely limit understanding of its nature and environmental roles. This review provides a characterization continuum of aquatic DOM, and demonstrate its biogeochemical implications, enabling in-depth insight into its nature and environmental roles. A synthesis of the effective DOM pretreatment strategies, comprising extraction and fractionation methods, and characterization techniques is presented. Additionally, the biogeochemical dynamics of aquatic DOM and its environmental implications are discussed. The findings indicate the collection of representative DOM samples from water as the first and critical step for characterizing its properties, dynamics, and environmental implications. However, various pretreatment procedures may alter DOM composition and structure, producing highly variable recoveries and even influencing its subsequent characterization. Therefore, complimentary use of various characterization techniques is highly recommended to obtain as much information on DOM as possible, as each characterization technique exhibits various advantages and limitations. Moreover, DOM could markedly change the physical and chemical properties of exogenous chemical species, influencing their transformation and mobility, and finally altering their potential bioavailability and toxicity. Several research gaps to be addressed include the impact of pretreatment on the composition and structure of aquatic DOM, molecular-level structural elucidation for DOM, and assessment of the effects of DOM dynamics on the fate, bioavailability and toxicity of exogenous chemical species.
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Affiliation(s)
- Hengfeng Zhang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China; International Science & Technology Cooperation Center for Urban Alternative Water Resources Development, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China
| | - Yucong Zheng
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China; International Science & Technology Cooperation Center for Urban Alternative Water Resources Development, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China
| | - Xiaochang C Wang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China; International Science & Technology Cooperation Center for Urban Alternative Water Resources Development, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China
| | - Yongkun Wang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China; International Science & Technology Cooperation Center for Urban Alternative Water Resources Development, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China
| | - Mawuli Dzakpasu
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China; International Science & Technology Cooperation Center for Urban Alternative Water Resources Development, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China.
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