A Dehydration-Induced Eukaryotic Translation Initiation Factor iso4G Identified in a Slow Wilting Soybean Cultivar Enhances Abiotic Stress Tolerance in Arabidopsis

Abstract

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.

Identification and Functional Analysis of a Protein Disulfide Isomerase (AtPDI1) in Arabidopsis thaliana

“…The washed seeds were allowed to germinate on 1/2 MS agar medium, or added 0.6 μM ABA, 200 mM NaCl, 300 mM mannitol, and 10 mM H 2 O 2 , respectively. The concentrations of ABA, NaCl, mannitol, and H 2 O 2 were determined based on the similar investigations ( Jia F. et al, 2015 ; Gallino et al, 2018 ). The concentrations used in the present study were stronger than general studies ( Brini et al, 2007 ; Wang et al, 2017 ).…”

Using the Knowledge of Post-transcriptional Regulations to Guide Gene Selections for Molecular Breeding in Soybean

“…Besides translation elongation, translation initiation factors could also regulate stress responses in soybean ( Alam et al, 2010 ; Yin and Komatsu, 2015 ; Gallino et al, 2018 ; Cho et al, 2019 ; Wang et al, 2021 ). eIF4G was reported to act as a hub in translation initiation and mediate the recruitment of additional initiation factors ( Sonenberg et al, 1978 ).…”

“…eIF4G was reported to act as a hub in translation initiation and mediate the recruitment of additional initiation factors ( Sonenberg et al, 1978 ). The eukaryotic translation initiation factor iso4G (GmeIFiso4G-1a) exhibited a specific drought induction profile in the slow-wilting soybean cultivar N7001 compared to the drought-sensitive TJS2049 soybean cultivar ( Gallino et al, 2018 ). The heterologous expression of soybean GmeIFiso4G-1a in Arabidopsis improved the tolerance to osmotic, salt, drought, and low-temperature stresses ( Gallino et al, 2018 ).…”

“…The eukaryotic translation initiation factor iso4G (GmeIFiso4G-1a) exhibited a specific drought induction profile in the slow-wilting soybean cultivar N7001 compared to the drought-sensitive TJS2049 soybean cultivar ( Gallino et al, 2018 ). The heterologous expression of soybean GmeIFiso4G-1a in Arabidopsis improved the tolerance to osmotic, salt, drought, and low-temperature stresses ( Gallino et al, 2018 ). In another report, it was shown that the Arabidopsis mutant eifiso4G1 , a homolog of the soybean GmeIFiso4G-1a , had increased sensitivity to submergence due to the disruption of the interaction between eIFiso4G1 and Snf1-related protein kinase 1 (SnRK1), which phosphorylates eIFiso4G1 for translational regulation ( Cho et al, 2019 ).…”

mRNA Recruiting eIF4 Factors Involved in Protein Synthesis and Its Regulation

“…Dysregulation of eIF4G is associated with the occurrence of several diseases like cancer and neurological disorders. , The expression of eIF4G is also regulated; however, in breast cancer, eIF4G was observed to be overexpressed . In plants, an increased level of expression of an isoform of eIF4G, eIFiso4G, is advantageous and confers drought resistance . eIF4G is also the target of viruses.…”