Identification of miRNA-mediated drought responsive multi-tiered regulatory network in drought tolerant rice, Nagina 22.

Abstract

Comparative characterization of microRNA-mediated stress regulatory networks in contrasting rice cultivars is critical to decipher plant stress response. Consequently, a multi-level comparative analysis, using sRNA sequencing, degradome analysis, enzymatic and metabolite assays and metal ion analysis, in drought tolerant and sensitive rice cultivars was conducted. The study identified a group of miRNAs "Cultivar-specific drought responsive" (CSDR)-miRNAs (osa-miR159f, osa-miR1871, osa-miR398b, osa-miR408-3p, osa-miR2878-5p, osa-miR528-5p and osa-miR397a) that were up-regulated in the flag-leaves of tolerant cultivar, Nagina 22 (N22) and Vandana, but down-regulated in the sensitive cultivar, Pusa Basmati 1 (PB1) and IR64, during drought. Interestingly, CSDR-miRNAs target several copper-protein coding transcripts like plantacyanins, laccases and Copper/Zinc superoxide dismutases (Cu/Zn SODs) and are themselves found to be similarly induced under simulated copper-starvation in both N22 and PB1. Transcription factor OsSPL9, implicated in Cu-homeostasis also interacted with osa-miR408-3p and osa-miR528-5p promoters. Further, N22 flag leaves showed lower SOD activity, accumulated ROS and had a higher stomata closure. Interestingly, compared to PB1, internal Cu levels significantly decreased in the N22 flag-leaves, during drought. Thus, the study identifies the unique drought mediated dynamism and interplay of Cu and ROS homeostasis, in the flag leaves of drought tolerant rice, wherein CSDR-miRNAs play a pivotal role.

• Authors: Sonia Balyan, Mukesh Kumar, Roseeta Devi Mutum, Utkarsh Raghuvanshi, Priyanka Agarwal, Saloni Mathur, Saurabh Raghuvanshi
• Journal: Scientific reports (Sci Rep) Vol. 7 Issue 1 Pg. 15446 (11 13 2017) ISSN: 2045-2322 [Electronic] England
• PMID: 29133823 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• MicroRNAs
• Reactive Oxygen Species
• Copper

Topics

• Acclimatization (genetics)
• Copper (metabolism)
• Droughts
• Gene Expression Profiling
• Gene Expression Regulation, Plant (physiology)
• Gene Regulatory Networks
• High-Throughput Nucleotide Sequencing
• MicroRNAs (genetics, metabolism)
• Oryza (physiology)
• Reactive Oxygen Species (metabolism)
• Sequence Analysis, RNA
• Stress, Physiological