Metabolomic Profiling of Drought-Tolerant and Susceptible Peanut (Arachis hypogaea L.) Genotypes in Response to Drought Stress

Abstract

Peanut is frequently constrained by extreme environmental conditions such as drought. To reveal the involvement of metabolites, TAG 24 (drought-tolerant) and JL 24 (drought-sensitive) peanut genotypes were investigated under control and 20% PEG 6000-mediated water scarcity conditions at the seedling stage. Samples were analyzed by gas chromatography–mass spectrometry (GC–MS) to identify untargeted metabolites and targeted metabolites, i.e., polyamines and polyphenols by high-performance liquid chromatography (HPLC) and ultrahigh-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS), respectively. The principal component analysis (PCA), partial least-squares discriminant analysis (PLS-DA), heat map, and cluster analysis were applied to the metabolomics data obtained by the GC–MS technique to determine the important metabolites for drought tolerance. Among 46 resulting metabolites, pentitol, phytol, xylonic acid, d-xylopyranose, stearic acid, and d-ribose were important drought-responsive metabolites. Agmatine and cadaverine were present in TAG 24 leaves and roots, respectively, during water-deficit conditions and believed to be the potential polyamines for drought tolerance. Polyphenols such as syringic acid and vanillic acid were produced more in the leaves of TAG 24, while catechin production was high in JL 24 during stress conditions. Seven metabolic pathways, namely, galactose metabolism, starch and sucrose metabolism, fructose and mannose metabolism, pentose and glucuronate interconversion, propanoate metabolism, amino sugar and nucleotide sugar metabolism, and biosynthesis of unsaturated fatty acids were significantly affected by water-deficit conditions. This study provides valuable information about the metabolic response of peanut to drought stress and metabolites identified, which encourages further study by transcriptome and proteomics to improve drought tolerance in peanut.

Transcriptome and Co-expression Network Analyses Reveal Differential Gene Expression and Pathways in Response to Severe Drought Stress in Peanut (Arachis hypogaea L.)

“…Simultaneously, Invertases (INVs) plays an important role in primary metabolism and plant development, which can hydrolyze sucrose into glucose and fructose (Ruan et al, 2010;Min et al, 2016) and contribute to osmotic adjustment under water deficit conditions (Konigshofer and Loppert, 2015). A similar result has shown that starch and sucrose metabolism was significantly affected by drought stress in peanut (Gundaraniya et al, 2020). These results showed genes involved in the regulation of starch and sucrose metabolism may play an important role in drought stress.…”

Alteration of Metabolites Accumulation in Maize Inbreds Leaf Tissue under Long-Term Water Deficit

“…In response to water deficit, the enhanced biosynthesis of cinnamic acid in leaves was reported for tolerance in peanut [ 35 , 36 ] and tobacco [ 37 ]. These findings are in line with ours, which show that long-term drought resulted in a highly pronounced cinnamic acid content increase in the DT maize inbreds (from 85% in DT2 to 284% in DT3 to 432% in DT1).…”

Metabolomics, a Powerful Tool for Understanding Plant Abiotic Stress

“…Regarding sugars, the concentrations of nigrose, seduheptose and galactose were enhanced in DS, whereas glucose, fructose and galactose levels increased in DT. Similarly, in both leaves and roots of peanuts submitted to drought stress, metabolomics analysis showed that pentitol, phytol, xylonic acid, d-xylopyranose, stearic acid and D-ribose were important drought-response metabolites [33]. Agmatine and cadaverine were present only in DT during drought.…”

“…In the one-way designs, the stress variable has been evaluated at two (control vs. stress) or more (control and various levels of the stress factor) levels. For instance, the effect of drought stress in the host's metabolome has usually been evaluated using a control vs. stress design [32][33][34], whereas various salt concentrations have been used to assess the effect of salinity in the plant's metabolome [35,36]. In both cases, the studies have been balanced as the same number of individuals has been evaluated at each level of stress.…”