Long Non-Coding RNAs in Plant Stress Responses: Mechanisms and Prospects

Abstract

Plants meet drought, salinity, temperature extremes, nutrient shortage and pathogens without the option of moving away, and their answer is a broad reprogramming of gene expression. Long non-coding RNAs, transcripts longer than about 200 nucleotides with little or no protein-coding capacity, have been added to the list of regulators involved. This narrative mini review summarises what the published literature shows about how such transcripts act in stress responses, drawing on well-studied cases in cold, heat, drought, salt, phosphate starvation and immunity. Mechanisms described include guiding chromatin-modifying complexes, interfering with transcription of neighbouring genes, acting as decoys for microRNAs, modulating splicing and helping to assemble transcriptional co-activators. The strongest evidence comes from a small number of Arabidopsis loci, whereas most lncRNAs listed in crop surveys are supported only by changes in expression. We discuss why that gap exists, what an adequate functional test would involve, and how genome editing and structural work might narrow it. No new data are reported.