lncRNAs and epigenetics regulate plant's resilience against biotic stresses.

With the advent of transcriptomic techniques involving single-stranded RNA sequencing and chromatin isolation by RNA purification-based sequencing, transcriptomic studies of coding and non-coding RNAs have been executed efficiently. These studies acknowledged the role of non-coding RNAs in modulating gene expression. Long non-coding RNAs (lncRNAs) are a kind of non-coding RNAs having lengths of >200 nucleotides, playing numerous roles in plant developmental processes such as photomorphogenesis, epigenetic changes, reproductive tissue development, and in regulating biotic and abiotic stresses. Epigenetic changes further control gene expression by changing their state to "ON-OFF" and also regulate stress memory and its transgenerational inheritance. With well-established regulatory mechanisms, they act as guides, scaffolds, signals, and decoys to modulate gene expression. They act as a major operator of post-transcriptional modifications such as histone and epigenetic modifications, and DNA methylations. The review elaborates on the roles of lncRNAs in plant immunity and also discusses how epigenetic markers alter gene expression in response to pest/pathogen attack and influences chromatin-associated stress memory as well as transgenerational inheritance of epigenetic imprints in plants. The review further summarizes some research studies on how histone modifications and DNA methylations resist pathogenic and pest attacks by activating defense-related genes.