Phenotypic and transcriptomic acclimation of the green microalga Raphidocelis subcapitata to high environmental levels of the herbicide diflufenican
Journal article, 2023

Herbicide pollution poses a worldwide threat to plants and freshwater ecosystems. However, the understanding of how organisms develop tolerance to these chemicals and the associated trade-off expenses are largely unknown. This study aims to investigate the physiological and transcriptional mechanisms underlying the acclimation of the green microalgal model species Raphidocelis subcapitata (Selenastraceae) towards the herbicide diflufenican, and the fitness costs associated with tolerance development. Algae were exposed for 12 weeks (corresponding to 100 generations) to diflufenican at the two environmental concentrations 10 and 310 ng/L. The monitoring of growth, pigment composition, and photosynthetic performance throughout the experiment revealed an initial dose-dependent stress phase (week 1) with an EC50 of 397 ng/L, followed by a time-dependent recovery phase during weeks 2 to 4. After week 4, R. subcapitata was acclimated to diflufenican exposure with a similar growth rate, content of carotenoids, and photosynthetic performance as the unexposed control algae. This acclimation state of the algae was explored in terms of tolerance acquisition, changes in the fatty acids composition, diflufenican removal rate, cell size, and changes in mRNA gene expression profile, revealing potential fitness costs associated with acclimation, such as up-regulation of genes related to cell division, structure, morphology, and reduction of cell size. Overall, this study demonstrates that R. subcapitata can quickly acclimate to environmental but toxic levels of diflufenican; however, the acclimation is associated with trade-off expenses that result in smaller cell size.

Diflufenican

Carotenoids

Acclimation

Microalgae

Transcriptomics

Author

Daniela Gómez-Martínez

University of Gothenburg

Johanna Bengtson

University of Gothenburg

Anders K. Nilsson

University of Gothenburg

Adrian K. Clarke

University of Gothenburg

R. Henrik Nilsson

University of Gothenburg

Erik Kristiansson

Chalmers, Mathematical Sciences, Applied Mathematics and Statistics

Natàlia Corcoll

University of Gothenburg

Science of the Total Environment

0048-9697 (ISSN) 1879-1026 (eISSN)

Vol. 875 162604

Subject Categories

Botany

Developmental Biology

Other Biological Topics

DOI

10.1016/j.scitotenv.2023.162604

PubMed

36878298

More information

Latest update

3/27/2023