Engineered nanoparticles at the redox interface: Rewiring ROS signaling and stress responses in plants.

Area of Science:

• Environmental Science
• Plant Biology
• Nanotechnology

Background:

• Engineered nanoparticles (ENPs) show potential for modulating plant stress responses.
• However, their mechanisms of action and associated risks require further investigation.

Purpose of the Study:

• To review recent advances in understanding how ENPs affect plant redox homeostasis and stress signaling.
• To highlight the importance of dose-dependency, the microbiome, and advanced imaging techniques.
• To propose a framework for the safe design and deployment of ENPs in agriculture.

Main Methods:

• Literature review integrating recent research on ENP-plant interactions.
• Analysis of mechanisms including redox activity, ion release, and effects on cellular processes.
• Emphasis on spatially resolved techniques for NP fate and redox dynamics.

Main Results:

• ENPs reprogram plant redox homeostasis via direct surface activity, nanozyme catalysis, ion release, and electron transport disruption.
• ENPs influence membrane properties, gene expression, metabolism, hormones, epigenetics, and the microbiome.
• Distinct reactive oxygen/nitrogen species (ROS/RNS) signatures activate signaling pathways like Ca2+ fluxes and MAPK cascades.

Conclusions:

• Dose-dependent, often hormetic, responses are critical.
• The rhizosphere microbiome plays a key role in ENP effects.
• A safe-by-design framework with standardized characterization and modeling is proposed for risk-informed agricultural applications.