Effect of glycine nitrogen on lettuce growth under soilless culture: a metabolomics approach to identify the main changes occurred in plant primary and secondary metabolism

Abstract

The novel methodology applied in this study can be used to characterize metabolites in lettuce. Accumulation of glycosylated flavonoids, amino acids and ascorbic acid in response to glycine supply provides strong evidence supporting the idea that using amino acids as an N source alters the nutritional value of vegetable crops. © 2017 Society of Chemical Industry.

Pakchoi Antioxidant Improvement and Differential Rhizobacterial Community Composition under Organic Fertilization

“…Most antioxidant measures (i.e., phenolic content, phenolic acid, and flavonoids) were negatively correlated to inorganic N (NO 3 − -N and/or NH 4 + -N) in the soils (Table 2). This concurs with our metabolic study that showed that NO 3 − -N as the N source hindered the accumulation of diverse intermediates involved in the phenylpropanoid and flavonoid pathways in lettuce and led to low antioxidant activity when compared to organic N (e.g., glycine) [7]. Similarly, this reasoning could be applied for the positive correlations between phenolic acid in plants, and TN and TON in soil (Table 2), which could be attributed to the increase of dissolved organic N content under a high TON condition [39], particularly low molecular weight organic N (e.g., amino acids and peptides) that can be used by the plant directly [40].…”

“…It is worth noting that positive correlations were found between plant antioxidant activity and increased metabolic functions by organic fertilizer amendment (i.e., amino acid metabolism, lipid metabolism, and metabolism of other amino acids). These results imply that functional prediction analysis could reflect the rhizosphere environment, showing that increased antioxidant activity in plants might be related to a high amino acid condition [7]. Although the distinct responses of plant performance were primarily caused by the incorporation of chemical and organic fertilizers, respectively, we propose that the shift in rhizobacterial community composition might also play important roles in mediating plant growth and health.…”

“…Compared to mineral fertilizers, the application of organic fertilizers is shown to induce systematic resistance by increasing the antioxidant enzymes in cucumber [6]. We recently further demonstrated that the use of organic N (e.g., glycine) increased the levels of various antioxidants in lettuce when compared with the nitrate application [7]. These results suggest that the antioxidant level in plants might be influenced by the form and concentration of N in soil.…”

Crop metabolomics: from diagnostics to assisted breeding

“…Metabolite profile analyses showed that pyruvic acid content was lower in glycinetreated lettuce than in the control. However, glycine supply increased the accumulation of glycosylated flavonoids, ascorbate and most amino acids but reduced the levels of phenolic acids and tricarboxylic acid (TCA) cycle intermediates (Yang et al 2018). Thus, this fertilization practice can be used as a potential strategy to obtain vegetable products of higher nutraceutical value.…”

Distinct Metabolome Changes during Seed Germination of Lettuce (Lactuca sativa L.) in Response to Thermal Stress as Revealed by Untargeted Metabolomics Analysis

“…For instance, Garcia et al using LC-MS based untargeted metabolomics approach compared differences of metabolome between two romaine lettuces after cutting and revealed that phenolic, terpenoid and lipid metabolites could explain the browning process in lettuce and be used as biomarkers to predict browning of fresh-cut lettuce [13,14]. An integrated GC-MS and LC-MS based untargeted metabolomic analysis was launched to compare the metabolic difference occurred in primary and secondary metabolism of lettuce hydroponically cultivated in organic and inorganic nitrogen culture, results suggested that organic nitrogen promoted the accumulation of glycosylated flavonoids, ascorbic acid and amino acids, but inhibited the content of phenolic acids and intermediates of the Krebs Cycle when compared to those lettuce cultivated under nitrate solution [15]. Yang et al used combined GC×GC-TOF/MS and UPLC-IMS-QTOF/MS non-targeted metabolomic strategy to detect and relatively quantify metabolites in leafy and head lettuce cultivars, and found that 16 metabolites including phenolic acid derivatives, glycosylated flavonoids, and one iridoid were present at significantly different levels in leaf and head type lettuces [16].…”