RNAi in Plant Protection: A Targeted Approach for Insect Pest Suppression

The biggest challenge faced by humanity in the 21 st is how to increase crop yields in a profitable,
efficient, and sustainable way. There are several issues constraining agricultural productivity,
such as damage by insect pests, diseases, and weeds. Currently, chemical pesticides remain the
major approach used for suppressing insect pests owing to their well-controlled effect.
Unfortunately, the excessive application of chemical pesticides has caused some serious
problems threatening the environment and human health. RNAi is a post-transcriptional gene
silencing mechanism initiated by the introduction of double-stranded RNA (dsRNA) into a cell.
This knockdown mechanism of gene by dsRNA is known as RNA interference (RNAi) in
animals and post-transcriptional gene silencing in plants. The basic dsRNA delivery methods
include microinjection, feeding, and soaking. To improve dsRNA delivery, various new
technologies, including cationic liposome–assisted, nanoparticle-enabled, symbiont-mediated,
and plant-mediated deliveries, have been developed. Chemically synthesized and modified
siRNA corresponding to P. xylostellaAChE genes cause significant mortality of the insect both
under laboratory and field conditions, which provides a novel strategy to control P. xylostella and
to develop bio-pesticides based on RNA interference technology. However, the widespread
adoption of RNAi for insect pest management faces several key challenges, including the high
cost of dsRNA synthesis, the need for efficient delivery to the target site, concerns over off-target
and non-target effects, and the potential development of resistance. Furthermore, innovative
approaches such as cell-free RNAi production and nanotechnology-mediated RNAi transfer offer
promising solutions to challenges like high synthesis costs and efficient dsRNA delivery, paving
the way for the practical application of RNAi in sustainable insect pest management.