The Critical Role of Small RNAs in Regulating Plant Innate Immunity

Abstract

Plants, due to their sessile nature, have an innate immune system that helps them to defend against different pathogen infections. The defense response of plants is composed of a highly regulated and complex molecular network, involving the extensive reprogramming of gene expression during the presence of pathogenic molecular signatures. Plants attain proper defense against pathogens through the transcriptional regulation of genes encoding defense regulatory proteins and hormone signaling pathways. Small RNAs are emerging as versatile regulators of plant development and act in different tiers of plant immunity, including pathogen-triggered immunity (PTI) and effector-triggered immunity (ETI). The versatile regulatory functions of small RNAs in plant growth and development and response to biotic and abiotic stresses have been widely studied in recent years. However, available information regarding the contribution of small RNAs in plant immunity against pathogens is more limited. This review article will focus on the role of small RNAs in innate immunity in plants.

Harnessing genetic resistance to rusts in wheat and integrated rust management methods to develop more durable resistant cultivars

“…Plants have a complex innate immune system that helps them to fight different pathogens. Wheat defense responses against pathogens consist of a strongly regulated and multifaceted molecular network which involves an extensive gene expression reprogramming during pathogen infections (Waheed et al, 2021). Distinct plant immune receptors recognize pathogen-derived chemicals, inducing different defensive responses that converge into common signaling Proposed model of adult plant resistance gene function.…”

“…Housekeeping and regulatory ncRNAs are the two main classes of ncRNAs. ncRNAs used to be regarded as trash DNA, but now they are an important part of a variety of regulatory processes (Urquiaga et al, 2021;Waheed et al, 2021). Regulatory ncRNAs can be classified according to their length into small RNAs (siRNAs) and long non-coding (lncRNAs) that only generate small peptides without being translated into proteins (Amor et al, 2009;Urquiaga et al, 2021;Waheed et al, 2021).…”

Viral suppressors from members of the family Closteroviridae combating antiviral RNA silencing: a tale of a sophisticated arms race in host-pathogen interactions

“…Furthermore, stabilized vsiRNA and miRNA duplexes were unzipped and separated into two strands, termed as guide and passenger strand, respectively, by helicase. The guide strand is incorporated into AGO proteins, facilitating the formation of a complex (RNA-induced silencing complex, RISC), while the passenger strand is shattered (Vaucheret 2008;Zhang et al 2015;Waheed et al 2021). To complete the effector phase of antiviral RNA silencing, RISCs target vsiRNA or miRNA complementary mRNAs and trigger their PTGS via endonucleolytic cleavage or translational inhibition (Waterhouse and Helliwell 2003;Brodersen et al 2008;Carbonell and Carrington 2015;Mengistu and Tenkegna 2021).…”

Action Mechanisms of Effectors in Plant-Pathogen Interaction

“…SA can be transformed in the chloroplast from chorismate, the final product of the shikimate pathway [ 218 , 219 , 220 , 221 , 222 ], and is involved in systemic acquired resistance (SAR) and induced systemic resistance (ISR) by hormone signaling [ 223 ]. SAR is a broad-spectrum type of resistance induced in host plants after primary infection, which can protect uninfected parts of plants from subsequent infections [ 54 , 224 ].…”