RNA Interference Mechanisms and Applications in Plant Pathology

Abstract

The origin of RNA interference (RNAi), the cell sentinel system widely shared among eukaryotes that recognizes RNAs and specifically degrades or prevents their translation in cells, is suggested to predate the last eukaryote common ancestor ( 138 ). Of particular relevance to plant pathology is that in plants, but also in some fungi, insects, and lower eukaryotes, RNAi is a primary and effective antiviral defense, and recent studies have revealed that small RNAs (sRNAs) involved in RNAi play important roles in other plant diseases, including those caused by cellular plant pathogens. Because of this, and because RNAi can be manipulated to interfere with the expression of endogenous genes in an intra- or interspecific manner, RNAi has been used as a tool in studies of gene function but also for plant protection. Here, we review the discovery of RNAi, canonical mechanisms, experimental and translational applications, and new RNA-based technologies of importance to plant pathology.

A Perspective on RNAi-Based Biopesticides

“…In addition to viruses and insects, RNAi has also been adopted for control of many other plant pests and pathogens in a research setting, including bacteria such as Agrobacterium, fungi such as powdery mildew, and nematodes such as Root knot nematodes (Rosa et al, 2018). Limitations to the genetic modification approach to crop protection have however been readily apparent for some time, and include low public acceptance in many markets and the inability to genetically transform many crop species (Zotti et al, 2018).…”

Genetic Engineering for Disease Resistance in Plants: Recent Progress and Future Perspectives

“…Plant-derived antimicrobial peptides and other compounds can suppress pathogenicity by direct detoxification or through inhibition of the activity of virulence factors (Kitajima and Sato, 1999;Thomma et al, 2002;Ahuja et al, 2012). Plants also employ RNA interference (RNAi) to detect invading viral pathogens and target the viral RNA for cleavage (Rosa et al, 2018).…”

Genetic modification to improve disease resistance in crops

“…The resulting small interfering (si)RNAs can be recruited by Argonaute (AGO) proteins that recognise and cleave complementary strands of RNA, resulting in gene silencing. RNAi-based resistance can be engineered against many viruses by expressing 'hairpin' structures, double-stranded RNA molecules that contain viral sequences, or simply by overexpressing dysfunctional viral genes (reviewed in Rosa et al, 2018). Moreover, a single double-stranded RNA molecule can be processed into a variety of siRNAs and thereby effectively target several viruses using one hairpin construct.…”