6PPD and 6PPD-Q Inhibit Macrophyte Photosynthesis by Targeting Photosynthetic Antenna: Multiomics and Computational...

Area of Science:

• Environmental toxicology
• Plant physiology
• Aquatic ecology

Background:

• N-(1,3-dimethylbutyl)-N '-phenyl-p-phenylenediamine (6PPD) and its derivative 6PPD-quinone (6PPD-Q) are emerging contaminants.
• Their photosynthetic toxicity mechanisms in aquatic macrophytes are not well understood.

Purpose of the Study:

• To elucidate the precise inhibitory mechanisms and toxic targets of 6PPD and 6PPD-Q in the photosynthetic pathways of Ceratophyllum demersum L. (C. demersum).
• To investigate the comparative toxicity of 6PPD and 6PPD-Q.

Main Methods:

• Combined physio-biochemical indicators, multiomics analysis (transcriptomics, metabolomics), and molecular docking simulations.
• Investigated effects on Ceratophyllum demersum L. (C. demersum).

Main Results:

• Photosynthetic antenna proteins identified as primary molecular targets for both 6PPD and 6PPD-Q.
• Disruption of photosynthetic electron transport efficiency and carbohydrate metabolism, indicating compromised carbon fixation.
• 6PPD-Q exhibited potentially greater toxicity due to enhanced binding with antenna proteins.

Conclusions:

• 6PPD and 6PPD-Q disrupt photosynthesis by targeting antenna proteins and impairing electron transport and carbon fixation.
• 6PPD-Q may be more toxic than 6PPD.
• These contaminants pose a risk to aquatic ecosystem productivity and stability.