RNA-Based Control of Fungal Pathogens in Plants

Abstract

Our duty to conserve global natural ecosystems is increasingly in conflict with our need to feed an expanding population. The use of conventional pesticides not only damages the environment and vulnerable biodiversity but can also still fail to prevent crop losses of 20–40% due to pests and pathogens. There is a growing call for more ecologically sustainable pathogen control measures. RNA-based biopesticides offer an eco-friendly alternative to the use of conventional fungicides for crop protection. The genetic modification (GM) of crops remains controversial in many countries, though expression of transgenes inducing pathogen-specific RNA interference (RNAi) has been proven effective against many agronomically important fungal pathogens. The topical application of pathogen-specific RNAi-inducing sprays is a more responsive, GM-free approach to conventional RNAi transgene-based crop protection. The specific targeting of essential pathogen genes, the development of RNAi-nanoparticle carrier spray formulations, and the possible structural modifications to the RNA molecules themselves are crucial to the success of this novel technology. Here, we outline the current understanding of gene silencing pathways in plants and fungi and summarize the pioneering and recent work exploring RNA-based biopesticides for crop protection against fungal pathogens, with a focus on spray-induced gene silencing (SIGS). Further, we discuss factors that could affect the success of RNA-based control strategies, including RNA uptake, stability, amplification, and movement within and between the plant host and pathogen, as well as the cost and design of RNA pesticides.

Challenges and Opportunities Arising from Host–Botrytis cinerea Interactions to Outline Novel and Sustainable Control Strategies: The Key Role of RNA Interference

“…Therefore, trans-kingdom RNA silencing in plant-fungal pathogen interactions has provided the general framework within which to develop a new category of RNA-based fungicides [ 376 ]. This perspective, in fact, has aroused great interest from scholars, as demonstrated by the numerous reviews published on this topic in recent years [ 364 , 433 , 467 , 468 , 470 , 514 , 515 , 516 , 517 , 518 ].…”

“…In recent years, the use of topical application of dsRNA has been investigated for its applications in plant protection. In particular, the dsRNA spraying technique has proven to be a valid delivery method as demonstrated in many studies concerning RNAi-based crop protection strategies [ 6 , 9 , 12 , 440 , 450 , 463 , 464 , 465 , 466 , 467 , 468 , 469 , 470 ].…”

A conserved fungal Knr4/Smi1 protein is vital for maintaining cell wall integrity and host plant pathogenesis

“…The high conservation and exclusivity of KNR4 within the fungal kingdom, combined with its absence in other eukaryotes and its conserved function across related species, suggest that KNR4 could be an ideal target for intervention. This could be achieved through the development of chemical fungicides that disrupt the protein’s function (Aamir et al, 2018) or through the application of RNA interference techniques (Cools and Hammond-Kosack, 2013; Machado et al, 2018; Mann et al, 2023). Stricter EU regulation of chemicals suitable for fungicide use in agricultural, medical and/or veterinary settings (European Commission, 2022), combined with significant losses in fungicide efficacy due to the evolution of pathogen populations means there is a pressing need to identify new target sites for control.…”

Modern Breeding Strategies and Tools for Durable Late Blight Resistance in Potato

“…The use of HIGS could be a much better option, when a critical and vital gene is targeted. It has been used successfully against viruses [ 186 , 187 ]. The main issue for the use of HIGS in Europe is the way that it is obtained via genetic transformation.…”