NMR-Based Metabolomic Screening for Metabolites Associated with Resistance to Meloidogyne javanica in Annona muricata Roots

Abstract

The resistance of Annona muricata roots to the nematode Meloidogyne javanica was investigated by nuclear magnetic resonance (NMR)-based metabolomics in combination with principal component analysis (PCA). Metabolic changes in roots exposed and not exposed to the nematode were evaluated and compared. In addition, the presence of nematicidal compounds in the root extracts was investigated through in vitro assay against Meloidogyne javanica secondstage juveniles. Plants exposed to nematodes showed significant changes in their metabolism after 24 h. Several resistance-related metabolites, including dopamine, xanthine and aromatic compounds, could be identified in the roots with the joint analysis of 1D/2D NMR and the loadings of PC3 (17.8%). A. muricata root chloroform extract, containing mainly acetogenins, has shown nematostatic activity against M. javanica, suggesting that a pre-formed defense mechanism can support the reported resistance. For the first time, metabolomic studies allowed to identify induced and pre-formed defense mechanisms and their related metabolites in Annona muricata.

A Phytochemical Perspective on Plant Defense Against Nematodes

“…Further NMR analysis of this fraction showed that it contained several acetogenins, a class of secondary metabolites common among the Annonaceae that have known insecticidal activity. No major metabolome shift was seen in nematode-inoculated plants compared to uninoculated plants at time points later than 2 days postinoculation, which supports the notion that the soursop seedlings were highly resistant and that nematodes could not successfully invade (Machado et al, 2019).…”

“…NMR metabolomics has also been used to study nematode interactions in seedlings of the soursop tree (Annona muricata), which is highly resistant to nematode infection (Machado et al, 2019). Extracts of root systems of soursop seedlings with or without M. javanica inoculation were harvested at various time points between 1 and 30 days after inoculation, analyzed through NMR and then used for bio-assay guided fractionation.…”

“…Three main solutions exist for this problem: using 2D-NMR methods (Moco et al, 2007;Kim et al, 2010Kim et al, , 2011Schripsema, 2010), coupling NMR to LC (Moco et al, 2007;Sumner et al, 2015), or fractionating the extract prior to NMR analysis (Moco et al, 2007;Kim et al, 2010). LC-NMR has not yet been used in studies of PPN, whereas fractionation and 2D NMR have been used with some success by e.g., Machado et al (2019).…”

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

“…Nevertheless, the majority of studies using 1 H NMR spectroscopy still predominantly rely on exclusive 1 H NMR usage. Only a limited few have established connections between toxicity bioassays and compound abundance, , compared the presence of diseases and physiological parameters, ,,,, or have used additional complementary analytical techniques to quantify and confirm metabolites of interest. ,,,, Multiomics combinations with transcriptomics (quantitative real-time PCR and RNA sequencing), proteomics (LC-MS proteomics with gene ontology enrichment analysis), and metabolomics with the use of other analytical techniques (Fourier-transform infrared spectroscopy (FT-IR), GC-MS, and LC-MS) were limited to five studies. ,,,, …”

Decoding Metabolic Reprogramming in Plants under Pathogen Attacks, a Comprehensive Review of Emerging Metabolomics Technologies to Maximize Their Applications

“…For example, 2D-NMR analysis improved the resolution of 1 H-NMR spectra, allowing the characterization of some phenylpropanoids such as chlorogenic acid, 3-O-caffeoyl quinic acid, and feruloyl quinic acid, posing their role as a resistance factor for thrips in chrysanthemum [ 104 ]. The joint analysis of 1D/2D NMR also revealed several metabolites responsible for resistance of Annona muricata roots to the nematode Meloidogyne javanica including dopamine, xanthine, and aromatic compounds [ 105 ]. NMR-based metabolomic profiling of potato leaves also revealed the upregulation of malic acid, methanol, and rutin and downregulation of sucrose in the resistant cultivars to late blight disease more than in the susceptible ones [ 106 ].…”