Integrated physiological, proteomic, and metabolomic analyses of pecan cultivar ‘Pawnee’ adaptation to salt stress

Abstract

The pecan is a salt-alkali-tolerant plant, and its fruit and wood have high economic value. This study aimed to explore the molecular mechanisms responsible for salt stress tolerance in the pecan grown under hydroponic conditions to simulate salt stress. The results showed that the photosynthetic rate (Pn) was reduced in response to salt stress, while the intercellular carbon dioxide concentrations (Ci) increased. The response of the pecan to salt stress was measured using iTRAQ (isobaric tags for relative or absolute quantitation) and LC/MS (liquid chromatography and mass spectrometry) non-targeted metabolomics technology. A total of 198 differentially expressed proteins (65 down-regulated and 133 up-regulated) and 538 differentially expressed metabolites (283 down-regulated and 255 up-regulated) were identified after exposure to salt stress for 48 h. These genes were associated with 21 core pathways, shown by Kyoto Encyclopedia of Genes and Genomes annotation and enrichment, including the metabolic pathways involved in nucleotide sugar and amino sugar metabolism, amino acid biosynthesis, starch and sucrose metabolism, and phenylpropane biosynthesis. In addition, analysis of interactions between the differentially expressed proteins and metabolites showed that two key nodes of the salt stress regulatory network, L-fucose and succinate, were up-regulated and down-regulated, respectively, suggesting that these metabolites may be significant for adaptations to salt stress. Finally, several key proteins were further verified by parallel reaction monitoring. In conclusion, this study used physiological, proteomic, and metabolomic methods to provide an important preliminary foundation for improving the salt tolerance of pecans.

Insights from a Multi-Omics Integration (MOI) Study in Oil Palm (Elaeis guineensis Jacq.) Response to Abiotic Stresses: Part One—Salinity

“…In the present study, SOA showed that carbohydrate metabolism and translation were the most affected biological process subcategories for differentially expressed genes and proteins, respectively. In addition to being a substrate for energy production, carbohydrates play a role in plant stress perception and signal transduction and can also mediate osmotic regulation and carbohydrate distribution [21].…”

Genome-Wide Analysis of the GDSL Genes in Pecan (Carya illinoensis K. Koch): Phylogeny, Structure, Promoter Cis-Elements, Co-Expression Networks, and Response to Salt Stresses

“…Previous studies have shown that AtFXG1 modifies xyloglucan oligosaccharides through the hydrolysis of t-fucosyl residues [ 41 ]. Furthermore, our group’s previous analysis concluded that the up-regulation of L-fucose accumulation is a critical feature of pecans’ metabolic regulatory network under salt stress [ 30 ]. CilGDSL42.57 , which is homologous to AtFXG1 , exhibits the largest expression change in response to salt stress.…”

“…Finally, HemI 1.0.3.7 software (http://hemi.biocuckoo.org/down.php, accessed on 20 August 2021) was used to generate the gene expression heatmaps based on the qRT-PCR data. Additionally, as previously reported [30], the protein extracts of pecan leaves were used to isobaric tags for relative and absolute quantitation (iTRAQ) analysis. To undertake a functional annotation analysis of the DEPs selected for GDSLs, we used the NCBI website (https://www.ncbi.nlm.nih.gov/, accessed on 9 November 2021).…”

Insights from a Multi-Omics Integration (MOI) Study in Oil Palm (Elaeis guineensis Jacq.) Response to Abiotic Stresses: Part Two—Drought

“…Post-translation modifications, such as protein phosphorylation, promote changes in those proteins that already existed in the cells before the onset of the stress and play roles important in plant resistance to abiotic stresses [ 24 , 25 ]. Carbohydrate metabolism also plays a role in plant stress perception and signal transduction, besides being a substrate for energy production and a mediator of osmotic regulation and carbohydrate distribution [ 26 ].…”