Evaluating the pesticidal impact of plant protease inhibitors: lethal weaponry in the co-evolutionary battle.

Abstract

In the arsenal of plant defense, protease inhibitors (PIs) are well-designed defensive products to counter field pests. PIs are produced in plant tissues by means of 'stable defense metabolite' and triggered on demand as the perception of the signal and well established as a part of plant active defense. PIs have been utilized for approximately four decades, initially as a gene-alone approach that was later replaced by multiple gene pyramiding/gene stacking due to insect adaptability towards the PI alone. By considering the adaptive responses of the pest to the single insecticidal gene, the concept of gene pyramiding gained continuous appreciation for the development of transgenic crops to deal with co-evolving pests. Gene pyramiding approaches are executed to bypass the insect's adaptive responses against PIs. Stacking PIs with additional insecticidal proteins, plastid engineering, recombinant proteinase inhibitors, RNAi-based methods and CRISPR/Cas9-mediated genome editing are the advanced tools and methods for next-generation pest management. Undoubtedly, the domain associated with the mechanism of PIs in the course of plant-pest interactions will occupy a central role for the advancement of more efficient and sustainable pest control strategies. © 2021 Society of Chemical Industry.