Genome–wide screening for novel, drought stress–responsive long non–coding RNAs in drought–stressed leaf transcriptome of drought tolerant and susceptible banana (Musa spp.) cultivars using Illumina high throughput sequencing.

Abstract

Long non-coding RNAs (LncRNAs) are one of the many layers of transcription in higher plants. LncRNAs are responsive to biotic and abiotic stresses and regulate genes. In our study, we have identified 905 novel lncRNAs from 8471 drought-responsive, novel transcripts of RNA-Seq reads from two banana cultivars, a drought-tolerant cv. ‘Saba’ (ABB) and -susceptible cv. ‘Grand Naine’ (AAA). Of these 905 lncRNAs, 75 (8.3 %) transcripts were natural antisense RNAs (NATs) and 2 transcripts identified as precursors of microRNA-miR156 and miR166. Among the 905 identified lncRNAs, 216, 150 and 279, 164 lncRNAs were induced and reduced to drought stress, respectively, in tolerant and susceptible in comparison to their equivalent controls. The remaining 22 lncRNA of tolerant cultivars was not regulated by drought stress. Of the 882 drought-responsive lncRNAs, 44 new lncRNAs were identified as induced. Musa lncRNAs were unevenly distributed in 11 chromosomes of Musa acuminata and no lncRNAs were found in chromosome-9 of drought-tolerant cultivar. The average lengths of lncRNAs were 683 nucleotides (nt). Drought-responsive differential expression of lncRNAs was found between +8.11585- and −4.04311-fold. Around 7.9 % of the identified lncRNAs were decoys of 85 conserved microRNAs. These findings will lay a basic platform for effective strategic planning of developing drought-resilient crop varieties.