Metabolic Profiling of Transgenic Potato Tubers Expressing Arabidopsis Dehydration Response Element-Binding Protein 1A (DREB1A)

Abstract

Untargeted metabolome analyses play a critical role in understanding possible metabolic fluctuations of crops under varying environmental conditions. This study reports metabolic profiles of transgenic potato tubers expressing the Arabidopsis DREB1A transcription factor gene, which induces expression of genes involved in environmental stress tolerance. A combination of targeted and untargeted metabolomics demonstrated considerable metabolome differences between the transgenic lines and nontransgenic parent cultivars. In the transgenic lines, stimulation of stress responses was suggested by elevated levels of the glutathione metabolite, γ-aminobutyric acid (GABA), and by the accumulation of β-cyanoalanine, a byproduct of ethylene biosynthesis. These results suggest that the Arabidopsis DREB1A expression might directly or indirectly enhance endogenous potato stress tolerance systems. The results indicate that transgenesis events could alter the metabolic compositions in food crops, and therefore metabolomics analysis could be a most valuable tool to monitor such changes.

The transcriptional regulatory network in the drought response and its crosstalk in abiotic stress responses including drought, cold, and heat

“…As mentioned above, these factors can be used to improve drought tolerance in a variety of crops. Our group has utilized these key TFs for the improvement of drought tolerance in crops including rice, wheat, and soybean in collaboration with international and domestic institutes (Pellegrineschi et al, 2004; Hong et al, 2006; Behnam et al, 2007; Bhatnagar-Mathur et al, 2007; Polizel et al, 2011; Datta et al, 2012; Ishizaki et al, 2012; Saint Pierre et al, 2012; Barbosa et al, 2013; Bhatnagar-Mathur et al, 2013; de Paiva Rolla et al, 2013; Engels et al, 2013; Iwaki et al, 2013). Some results using crops including rice and peanut have shown that stress-specific overexpression of DREB1A improves drought tolerance and grain yield compared with controls in the field (Datta et al, 2012; Bhatnagar-Mathur et al, 2013).…”

“…Thus, the function of the DREB1/CBF regulon in the regulation of cold stress responses is widely conserved in angiosperms. Overexpression of DREB/CBF TFs has been reported to enhance drought tolerance in transgenic crops including chrysanthemum (Hong et al, 2006), peanut (Bhatnagar-Mathur et al, 2007, Bhatnagar-Mathur et al, 2013), potato (Behnam et al, 2007; Iwaki et al, 2013), rice (Oh et al, 2005; Ito et al, 2006; Datta et al, 2012), soybean (Polizel et al, 2011; de Paiva Rolla et al, 2013), tobacco (Kasuga et al, 2004), tomato (Hsieh et al, 2002a,b), and wheat (Pellegrineschi et al, 2004; Saint Pierre et al, 2012). For example, rice DREB1/CBF-type TFs involved in cold-responsive gene expression also conferred improved tolerance to drought in transgenic rice (Ito et al, 2006).…”

Global metabolite profiling based on GC–MS and LC–MS/MS analyses in ABF3-overexpressing soybean with enhanced drought tolerance

“…This approach has already revealed a more comprehensive and holistic framework for presenting possible compositional differences between transgenic and conventionally bred plants [13,14]. Furthermore, it has helped to identify unfavorable metabolites, including toxic compounds, or any unintended metabolic changes due to such genetic modifications [15][16][17].…”

Seed Metabolome Analysis of a Transgenic Rice Line Expressing Cholera Toxin B-subunit

“…The l -3-cyanoalanine content of the maximum dose of MucoRice-CTB (6 g) is thus estimated to be 5.7 μg. The l -3-cyanoalanine content in MR-CTB51A brown rice (956 ng g −1 DW) is lower than that in non-transgenic potato tubers (1.8 μg g −1 fresh weight) 26 . No serious adverse responses have been attributed to daily rice consumption 43 .…”