Coding and non-coding transcripts modulated by transparent and blue PET micro-nanoplastics in Arabidopsis thaliana

Area of Science:

• Plant biology
• Environmental toxicology
• Molecular genetics

Background:

• Micro- and nanoplastics (MNPs) are emerging environmental contaminants.
• Understanding MNP effects on plants is crucial for ecological risk assessment.
• Polyethylene terephthalate (PET) is a common plastic pollutant.

Purpose of the Study:

• To investigate the molecular responses of *Arabidopsis thaliana* to different colored PET micro- and nanoplastics.
• To elucidate the role of long non-coding RNAs (lncRNAs) in plant gene expression regulation after MNP exposure.

Main Methods:

• Hydroponic cultivation of *Arabidopsis thaliana*.
• Exposure to transparent (Tr-PET) and blue (Bl-PET) micro- and nanoplastics at environmentally relevant concentrations.
• Analysis of root length, rosette area, oxidative stress markers, and gene expression (including lncRNAs) using transcriptomic profiling.

Main Results:

• Both Tr-PET and Bl-PET reduced root length; Bl-PET also reduced rosette area.
• MNPs induced oxidative stress markers.
• Tr-PET upregulated xenobiotic signaling genes, while Bl-PET induced abiotic stress genes.
• ABA response genes were repressed, and brassinosteroid genes were differentially regulated.
• Tr-PET significantly altered lncRNA expression (80 lncRNAs) compared to Bl-PET (11 lncRNAs).
• Regulated lncRNAs potentially interact with protein-coding genes involved in detoxification, stress response, and hormone signaling.

Conclusions:

• PET MNPs negatively impact plant growth and induce molecular stress responses.
• lncRNAs are significantly involved in regulating plant gene expression in response to MNP exposure.
• Future research should incorporate non-coding RNA analysis for a comprehensive understanding of MNP toxicity in plants.