Metabolomics reveals the response of hydroprimed maize to mitigate the impact of soil salinization

Abstract

Soil salinization is a major environmental stressor hindering global crop production. Hydropriming has emerged as a promising approach to reduce salt stress and enhance crop yields on salinized land. However, a better mechanisitic understanding is required to improve salt stress tolerance. We used a biochemical and metabolomics approach to study the effect of salt stress of hydroprimed maize to identify the types and variation of differentially accumulated metabolites. Here we show that hydropriming significantly increased catalase (CAT) activity, soluble sugar and proline content, decreased superoxide dismutase (SOD) activity and peroxide (H2O2) content. Conversely, hydropriming had no significant effect on POD activity, soluble protein and MDA content under salt stress. The Metabolite analysis indicated that salt stress significantly increased the content of 1278 metabolites and decreased the content of 1044 metabolites. Ethisterone (progesterone) was the most important metabolite produced in the roots of unprimed samples in response to salt s tress. Pathway enrichment analysis indicated that flavone and flavonol biosynthesis, which relate to scavenging reactive oxygen species (ROS), was the most significant metabolic pathway related to salt stress. Hydropriming significantly increased the content of 873 metabolites and significantly decreased the content of 1313 metabolites. 5-Methyltetrahydrofolate, a methyl donor for methionine, was the most important metabolite produced in the roots of hydroprimed samples in response to salt stress. Plant growth regulator, such as melatonin, gibberellin A8, estrone, abscisic acid and brassinolide involved in both treatment. Our results not only verify the roles of key metabolites in resisting salt stress, but also further evidence that flavone and flavonol biosynthesis and plant growth regulator relate to salt tolerance.

Integrated transcriptomic and metabolomic analyses elucidate the mechanism of flavonoid biosynthesis in the regulation of mulberry seed germination under salt stress

“…These results showed that the flavonoid biosynthesis pathway is important for mulberry seed germination under salt stress. Our results are consistent with previous studies reporting that flavones and flavonols accumulate in plants exposed to salt stress and that they enhance plant salinity tolerance by scavenging ROS [ 49 , 70 ].…”

“…Quercetin-3-O-glucoside has been shown to have high antioxidant activity, and moderate salinity induces the synthesis of quercetin-3-O-glucoside [ 48 ]. In addition, maize plants exhibited a significant increase in relevant metabolites, including quercetin 3-O-glucoside, kaempferol 3-O glucoside, and quercetin 3-methyl ether, under salt stress [ 49 ], which is similar to the results of this study. Taxifolin (dihydroquercetin) and its derivatives are flavonoids with important medicinal value that are widely distributed in plants and play important roles in the defense against biotic and abiotic stresses [ 50 , 51 ].…”