Roles of long non-coding RNAs in plant immunity

Abstract

Robust plant immune systems are fine-tuned by both protein-coding genes and non-coding RNAs. Long non-coding RNAs (lncRNAs) refer to RNAs with a length of more than 200 nt and usually do not have protein-coding function and do not belong to any other well-known non-coding RNA types. The non-protein-coding, low expression, and non-conservative characteristics of lncRNAs restrict their recognition. Although studies of lncRNAs in plants are in the early stage, emerging studies have shown that plants employ lncRNAs to regulate plant immunity. Moreover, in response to stresses, numerous lncRNAs are differentially expressed, which manifests the actions of low-expressed lncRNAs and makes plant–microbe/insect interactions a convenient system to study the functions of lncRNAs. Here, we summarize the current advances in plant lncRNAs, discuss their regulatory effects in different stages of plant immunity, and highlight their roles in diverse plant–microbe/insect interactions. These insights will not only strengthen our understanding of the roles and actions of lncRNAs in plant–microbe/insect interactions but also provide novel insight into plant immune responses and a basis for further research in this field.

RNA Polymerases IV and V Are Involved in Olive Fruit Development

“…It has been demonstrated that RNA pol IV and V play a role in silencing, plant growth, development, response to environmental changes or plant immunity [4][5][6][7][8][9][10][11][12][22][23][24]. Therefore, we can speculate that the regulation of the gene expression of these RNA pols could be expected in response to some growth conditions.…”

“…Taken together, these data suggest that RNA pol IV and V may play a major role in early fruit development steps. As RNA pol IV and V have been proposed to participate in the transcription of lncRNAs [24,[31][32][33][34][35][36][37][38], we can speculate about a transcriptional response by these types of transcripts during this development process.…”

“…Plant-specific RNA pol IV and V, which have evolved from RNA pol II through duplication and functional divergence, also contain 12 subunits. These two enzymes that are involved in epigenetic regulation to synthesise siRNAs play roles in transcriptional silencing via RNA-directed DNA methylation (RdDM), and in non-coding RNAs' participation in plant growth, development, response to environmental changes or plant immunity [4][5][6][7][8][9][10][11][12][22][23][24].…”

“…RNA pol IV and V have been reported to be involved in the biogenesis and functionality of 24 nt siRNA, which participates in RdDM [9,12,25,30]. RNA pol IV and V have also been proposed as participating in the transcription of long non-coding RNAs (lncRNAs) [24,[31][32][33][34][35][36][37][38]. Some of these lncRNAs are the intermediary of siRNA and are found within intergenic regions [34].…”

Plant Functional Genomics Based on High‐Throughput CRISPR Library Knockout Screening: A Perspective

“…used CRISPR‐Cas9 to edit the promoter of CLE genes to enhance grain‐yield‐related traits in maize. [ 146 ] For lncRNAs that are considered to play vital roles in plant immunity and diverse plant‐microbe or insect interaction, [ 152 ] two lncRNAs were mutated with the CRISPR‐Cas9 system, leading to a negative effect on aphid resistance and a decrease of jasmonic acid content. [ 151 ] However, high‐throughput CRISPR library interrogation of these elements in plants has yet to be reported, and only one such study was found to be carried out in Bombyx mori targeting promoters with a large‐scale sgRNA pool.…”