“Plant long non-coding RNAs – Emerging modulator of gene activity”

   The central dogma of Molecular Biology suggests the primary role of RNA is to convert the information stored in DNA into proteins via translation. RNA carries the genetic information that is translated into ribosomes into various proteins necessary for cellular process. In reality, there is much more to the RNA story. The coding RNA that is translated into proteins accounts to 3 percent of the total RNA. The remaining RNA that do not code for proteins are the non-coding gene that plays a essential role in gene regulation.

Among the non-coding RNA, long non-coding RNA (lncRNA) is defined as RNA transcripts longer than 200 nucleotides. Also known as ‘modulators of gene expression’ they are synthesized by RNA polymerase II. The subcellular localization of lncRNA is the primary dependent of molecular functions of lncRNA. For regulating the gene mechanism these lncRNA acts a signal, decoy, guide, scaffold and as a sponge. Emerging evidence states that lncRNA are more responsive towards biotic and abiotic stresses2.

Genome wide transcription analysis was performed in response to drought stress in maize inbred line B73 from three different tissues – the ear, tassel and the leaf across four developmental stages. Among them, it was discovered that the reproductive stage (R1) was most sensitive growth stage with more lncRNA showing altered expression upon drought stress1. Several lncRNA were found by RNA sequencing in tomato samples infected with Tomato Yellow Leaf Curl Virus (TYLCV). It also shows that the lncRNA slylnc0195 acts as an endogenous target mimic for miR166a involved in TYLCV infection. miRNA was down regulated and slylnc0195 increased on exposure to virus. By silencing the lncRNA, the expression of the miR166a target genes and subsequently the virus accumulation in lncRNA silenced plants were increased by 70 fold3.

The rapidly increasing number of plants lncRNA and their multifaceted regulatory role in governing various biological processes is becoming a hotspot in biological research. The availability of comprehensive atlas of lncRNA across whole genome in crop plants coupled with comprehensive understanding of the molecular mechanism that regulate various response will enable the lncRNA as potential biomarkers for tailoring different responses in plants.

References 

1. PANG J, ZHANG X, MA X, ZHAO J., 2019, Spatio-Temporal Transcriptional Dynamics Maize Long Non-Coding RNAs Responsive to Drought Stress. Genes(Basel).,10(2):138. 

2. STATELLO, L., GUO, CJ., CHEN, LL. et al., 2021, Gene regulation by long non-coding RNAs and its biological functions. Nat Rev Mol Cell Biol., 22:96–118.

 3. WANG, J., YU, W., YANG, Y. et al., 2015, Genome-wide analysis of tomato long non- coding RNAs and identification as endogenous target mimic for microRNA in response to TYLCV infection. Sci Rep.,5:16946.