Seed Infiltration with Polymer-Functionalized Carbon Dots Induces a Biotic Stress Response in Tomato (Solanum lycopersicum L.)

Global food security is a pressing issue in our society.
Maintaining
food security in coming years will require improving crop yield, as
well as increased resiliency to abiotic and biotic stress. Nanoscale
materials have increasingly been proposed as a tool which could be
used to meet these challenges. However, much research is needed to
optimize nanoparticle design and crop application for this to become
a reality. In this study, we investigated the impact of polymer-functionalized
carbon dots on tomatoes (Solanum lycopersicum L.). Tomato seeds were vacuum infiltrated with carbon dots and then
grown for 3 weeks before collection of phenotypic and transcriptomic
data. No changes to fresh biomass or chlorophyll content were observed,
indicating that these particles can be applied without overt harm
to the plant at early growth stages. In addition, changes in gene
expression suggest that polymer-functionalized carbon dots can initiate
the expression of biochemical pathways associated with a pathogen
resistance response in tomato plants. Specifically, genes involved
in ethylene signaling, ethylene production, and camalexin synthesis
were upregulated. These findings suggest that seed priming with carbon
dots may improve plant tolerance to biotic stress by modulating ethylene
signaling pathways. Carbon dots could also be loaded with nutrients
or other agrochemicals to create a multifunctional platform. Future
work should focus on understanding the mechanisms by which nanoparticles
can modulate ethylene signaling, enabling use of this knowledge to
develop sustainable and effective nanoparticles for agricultural applications.