Project description:miRNAs play an important role in growth, development, stress resilience and epigenetic modifications of plants. However, the effect of calcium nutrition on miRNA expression in orphan crops such as tef ((Eragrostis tef) remained unknown. In this study, we analyzed genome-wise miRNAs of roots and shoots in response to long-term calcium deficiency in tef. MiRNA-seq followed by bioinformatic analysis identified a large number of small RNAs with size ranging from 17bp to 35bp. A total 1380 miRNAs were identified in plants experiencing long-term Ca deficiency, while 1495 miRNAs were identified in the control plants. Among the miRNAs identified in this study, 161 miRNAs were known, and 348 miRNAs were novel while the remaining miRNAs were uncharacterized. Putative target genes and their functions were predicted for all the known and novel miRNAs. Based on gene ontology (GO) analysis, the target genes were found to have various biological and molecular functions including calcium uptake and transport. Pairwise comparison of differentially expressed miRNAs revealed that some of the miRNAs were specifically enriched in roots or shoots of low calcium treated plants as compared to control plants. Further characterization of the miRNAs and their targets detected in this study will help in identifying Ca deficiency responses not only in tef but also in related orphan crops
Project description:The orphan crop, Eragrostis tef, was subjected to controlled drought conditions to observe the physiological parameters and proteins changing in response to dehydration stress. Physiological measurements involving electrolyte leakage, chlorophyll fluorescence and ultra-structural analysis showed tef plants to tolerate water loss to 50% RWC before adverse effects in leaf tissues were observed. Proteomic analysis using iTRAQ mass spectrometry and appropriate database searching enabled the detection of 5727 proteins, of which 211 proteins, including a number of spliced variants, were found to be differentially regulated with imposed stress conditions. Validation of the stress-related proteins, fructose-bisphosphate aldolase (FBA), glutamine synthetase (GLN) and the protective antioxidant proteins, monodehydroascorbate reductase (MDHAR) and peroxidase (POX), using immunodetection and enzymatic assay confirmed protein presence according to iTRAQ findings and showed increased protein abundance levels and enzymatic activity in response to water-deficit. GO-term enrichment and analysis revealed terms involved in biotic and abiotic stress response, signaling, transport, cellular homeostasis and pentose metabolic processes, to be enriched in tef up-regulated proteins, while terms linked to ROS-producing processes under water-deficit, such as photosynthesis and associated light harvesting reactions, manganese transport and homeostasis, the synthesis of sugars and cell wall catabolism and modification, to be enriched in tef down-regulated proteins.