Redox status upon herbicides application in the control of Lolium multiflorum (2n and 4n) as weed

Abstract

Lolium multiflorum Lam. is a winter weed of difficult control found as diploid (2n) and tetraploid plants (4n). Our study aimed to evaluate the responses of antioxidant enzymes and lipid peroxidation, in both diploid and tetraploid ryegrass varieties. Treatments consisted of control plants (without any herbicide application), and four herbicides with different mechanisms of action. Leaf material was collected 36 h after treatment imposition to determine the lipid peroxidation by ferrous oxidation-xylenol (FOX) content, and the activity of the enzymes superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPX), glutathione-S-transferase (GST), and δ-aminolevulinic acid dehydratase (ALAD). Both ryegrass varieties showed oxidative stress mainly due to a downregulated decreased (>31%) in SOD activity and an increase (>32%) in lipid peroxidation (FOX), mainly in ryegrass genotypes exposed to haloxyfop, glyphosate, and iodosulfuron. On the other hand, clethodim-treated plants had an increase in SOD and APX activities, associated with a reduced ALAD activity in both 2n (32%) and 4n (11%) genotypes. In general, the 2n genotype was more affected than the 4n genotype.

Keywords:

• Antioxidant enzymes
• resistance
• oxidative stress
• weed
• ryegrass

Ethical approval

The research article ensures objectivity and transparency in research and secures that accepted principles of ethical and professional conduct have been followed. This original research article does not contain any studies with human participants and animals performed by any of the authors.

Author contributions

RR Kaiser and L Galon designed the study. R Baldessari conducted the experiments. WA Tamagno, NT Sutorillo, and C Alves performed the biochemical analysis. WA Tamagno performed the statistical analyses. WA Tamagno analyzed and discussed the data. WA Tamagno and C Müller wrote the manuscript with contributions from other authors. All authors read and approved the manuscript.

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

The authors thank the National Council for Scientific and Technological Development (CNPq), the Research Support Foundation of the State of Rio Grande do Sul (FAPERGS), the Sertão Federal Institute of Rio Grande do Sul – Campus Sertão (IFRS) and the Federal University of Fronteira Sul – campus Erechim, for providing financial support. L Galon is grateful to the CNPq [PQ, no. 306927/2019-5], and C Müller to the Coordination for the Improvement of Higher Education Personnel [CAPES/PNPD, no. 88887.352933/2019-00] for their fellowships.