Nanomediated Stimulation: An Alternative to Brassinolide Hormone Replacement Therapy for Plant Resistance Activation

Facing
harsher losses of crop yield due to virus infection, it
is critical to reduce yield loss by improving plants’ disease
resistance. Here, we proposed using nanoparticles to prestimulate Nicotiana benthamiana as a nanomediated brassinolide
(BR) hormone replacement therapy to trigger immune responses and subsequently
increase plant immunity against viruses. Our results showed the prestimulated
leaves of zinc oxide nanoparticles (ZnONPs) exhibit accelerated antiviral
capability, and the plant resistance activation was increased with
a decrease in the ZnONP size. Transcriptome data and hormone assays
revealed that ZnONP stimulation activated the brassinolide hormone
signaling pathway and increased the brassinolide concentration. Importantly,
the induced activity of ZnONPs on antiviral capability could be eliminated
by virus-mediated silencing of key genes of brassinolide in Nicotiana benthamiana. In summary, we showed prestimulated
plants with ZnONPs induced systemic resistance to TMV by activating
the brassinolide pathways. This simple nanostimulant-based hormone
replacement therapy may alleviate pathogen infection in crop plants
and reduce the need for pesticides.