Original Research ARTICLE
A dehydration-induced eukaryotic translation initiation factor iso4G identified in a slow wilting soybean cultivar enhances abiotic stress tolerance in Arabidopsis.
- 1Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Uruguay
- 2Departamento de Biología Vegetal, Facultad de Agronomía, Universidad de la República, Uruguay
- 3Unidad de Biotecnología, National Institute of Agricultural Research (INIA), Uruguay
Water is usually the main limiting factor for soybean productivity worldwide and yet advances in genetic improvement for drought resistance in this crop are still limited. In the present study, we investigated the physiological and molecular responses to drought in two soybean contrasting genotypes, a slow wilting N7001 and a drought sensitive TJS2049 cultivars. Measurements of stomatal conductance, carbon isotope ratios and accumulated dry matter showed that N7001 responds to drought by employing mechanisms resulting in a more efficient water use than TJS2049.
To provide an insight into the molecular mechanisms that these cultivars employ to deal with water stress, their early and late transcriptional responses to drought were analyzed by suppression subtractive hybridization. A number of differentially regulated genes from N7001 were identified and their expression pattern was compared between in this genotype and TJS2049.
Overall, the data set indicated that N7001 responds to drought earlier than TJ2049 by up-regulating a larger number of genes, most of them encoding proteins with regulatory and signaling functions. The data supports the idea that at least some of the phenotypic differences between slow wilting and drought sensitive plants may rely on the regulation of the level and timing of expression of specific genes.
One of the genes that exhibited a marked N7001-specific drought induction profile encoded a eukaryotic translation initiation factor iso4G (GmeIFiso4G-1a). GmeIFiso4G-1a is one of four members of this protein family in soybean, all of them sharing high sequence identity with each other. In silico analysis of GmeIFiso4G-1 promoter sequences suggested a possible functional specialization between distinct family members, which can attain differences at the transcriptional level. Conditional overexpression of GmeIFiso4G-1a in Arabidopsis conferred the transgenic plants increased tolerance to osmotic, salt, drought and low temperature stress, providing a strong experimental evidence for a direct association between a protein of this class and general abiotic stress tolerance mechanisms. Moreover, the results of this work reinforce the importance of the control of protein synthesis as a central mechanism of stress adaptation and opens up for new strategies for improving crop performance under stress.
Keywords: Soybean, drought, translation initiation, abiotic stress, eIFiso4G, Arabidopsis
Received: 22 Dec 2017;
Accepted: 14 Feb 2018.
Edited by:Alejandra A. Covarrubias, Universidad Nacional Autónoma de México, Mexico
Reviewed by:Aureliano Bombarely, Virginia Tech, United States
Alejandro Ferrando, Universitat Politècnica de València, Spain
Copyright: © 2018 Gallino, Ruibal, Casaretto, Fleitas, Bonnecarrère, Borsani and Vidal. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: PhD. Sabina Vidal, VIDAL., Facultad de Ciencias, Universidad de la República, Instituto de Química Biológica, Igua 4225, Montevideo, Igua 4225, Montevideo, 11400, Montevideo, Uruguay, email@example.com