A Proteomic Approach to Investigate the Drought Response in the Orphan Crop Eragrostis tef

• Published in: Proteomes Vol. 5; no. 4; p. 32
• Main Authors: Kamies, Rizqah, Farrant, Jill M, Tadele, Zerihun, Cannarozzi, Gina, Rafudeen, Mohammed Suhail
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 15.11.2017; MDPI
• Subjects: Antioxidants; Cell walls; Cellular stress response; Chlorophyll; Dehydration; drought-stress; Enzymatic activity; Eragrostis tef; Fructose; Fructose-bisphosphate aldolase; functional enrichment analysis; GO-term; Homeostasis; iTRAQ; Manganese; Mass spectroscopy; Peroxidase; Photosynthesis; physiological characterisation; Physiology; Proteins; quantitative proteomics; Reactive oxygen species; Reductase; stress-responsive proteins; tef; Water content; Water loss; functional enrichment analysis; physiological characterisation; stress-responsive proteins; tef; drought-stress; GO-term; iTRAQ; quantitative proteomics
• ISSN: 2227-7382; 2227-7382
• DOI: 10.3390/proteomes5040032

The orphan crop, , 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 tolerated water loss to 50% relative water content (RWC) before adverse effects in leaf tissues were observed. Proteomic analysis using isobaric tag for relative and absolute quantification (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 the imposed stress conditions. Validation of the iTRAQ dataset was done with selected stress-related proteins, fructose-bisphosphate aldolase (FBA) and the protective antioxidant proteins, monodehydroascorbate reductase (MDHAR) and peroxidase (POX). Western blot analyses confirmed protein presence and showed increased protein abundance levels during water deficit while enzymatic activity for FBA, MDHAR and POX increased at selected RWC points. Gene ontology (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 upregulated proteins, while terms linked to reactive oxygen species (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 downregulated proteins.