The Different Metabolic Responses of Resistant and Susceptible Wheats to Fusarium graminearum Inoculation

Twenty Years of 1H NMR Plant Metabolomics: A Way Forward toward Assessment of Plant Metabolites for Constitutive and Inducible Defenses to Biotic Stress

Metabolomics has become an important tool in elucidating the complex relationship between a plant genotype and phenotype. For over 20 years, nuclear magnetic resonance (NMR) spectroscopy has been known for its robustness, quantitative capabilities, simplicity, and cost-efficiency. 1H NMR is the method of choice for analyzing a broad range of relatively abundant metabolites, which can be used for both capturing the plant chemical profile at one point in time and understanding the pathways that underpin plant defense. This systematic Review explores how 1H NMR-based plant metabolomics has contributed to understanding the role of various compounds in plant responses to biotic stress, focusing on both primary and secondary metabolites. It clarifies the challenges and advantages of using 1H NMR in plant metabolomics, interprets common trends observed, and suggests guidelines for method development and establishing standard procedures.

Combined NMR and MS-based metabonomics and real-time PCR analyses reveal dynamic metabolic changes of Ganoderma lucidum during fruiting body growing

Ganoderma lucidum (G. lucidum) is a rare medicinal fungus with various beneficial properties. One of its main components, ganoderic acids (GAs), are important triterpenoids known for their sedative and analgesic, hepatoprotective, and anti-tumor activities. Understanding the growth and development of the G. lucidum fruiting body is crucial for determining the optimal time to harvest them. In this study, we used nuclear magnetic resonance (NMR) spectroscopy to systematically characterize the metabolites of G. lucidum at seven distinct developmental stages. We also measured the contents of seven kinds of GAs using LC-MS/MS. A total of 49 metabolites were detected in G. lucidum, including amino acids, sugars, organic acids and GAs. During the transition from the bud development period (I) to the budding period (II), we observed a rapid accumulation of glucose, tyrosine, nicotinamide ribotide, inosine and GAs. After the budding period, the contents of most metabolites decreased until the mature period (VII). In addition, the contents of GAs showed an initial raising, followed by a decline during the elongation period, except for GAF, which exhibited a rapid raise during the mature stage. We also detected the expression of several genes involved in GA synthesis, finding that most genes including 16 cytochrome P450 monooxygenase were all down-regulated during periods IV and VII compared to period I. These findings provide valuable insights into the dynamic metabolic profiles of G. lucidum throughout its growth stage, and it is recommended to harvest G. lucidum at period IV.

Metabolic Profiling Identifies Changes in the Winter Wheat Grains Following Fusarium Treatment at Two Locations in Croatia

Fusarium head blight (FHB) is one of the most dangerous diseases of winter wheat, resulting in reduced grain yield and quality, and production of mycotoxins by the Fusarium fungi. In the present study, changes in the grain metabolomics of winter wheat samples infected with Fusarium spp. and corresponding non-infected samples from two locations in Croatia were investigated by GC-MS. A Mann-Whitney test revealed that 24 metabolites detected were significantly separated between Fusarium-inoculated and non-infected samples during the variety by treatment interactions. The results confirmed that in grains of six FHB-resistant varieties, ten metabolites were identified as possible resistance-related metabolites. These metabolites included heptadecanoic acid, 9-(Z)-hexadecenoic acid, sophorose, and secolaganin in grains of FHB-resistant varieties at the Osijek location, as well as 2-methylaminomethyltartronic acid, maleamic acid, 4-hydroxyphenylacetonitrile, 1,4-lactonearabinonic acid, secolaganin, and alanine in grains of FHB-resistant varieties at the Tovarnik location. Moreover, on the PCA bi-plot, FHB-susceptible wheat varieties were closer to glycyl proline, decanoic acid, and lactic acid dimer that could have affected other metabolites, and thus, suppressed resistance to FHB. Although defense reactions were genetically conditioned and variety specific, resulting metabolomics changes may give insight into defense-related pathways that could be manipulated to engineer plants with improved resistance to the pathogen.