Disclosing hidden metabolic traits in plant-fungal interactions: Identification of hub metabolites by correlation network analysis

NIEVA AS; ROMERO FM; ERBAN A; CARRASCO P; RUIZ OA; KOPKA J

Congreso; XII Argentine Congress of Bioinformatics and Computational Biology; 2022

The forage legume Lotus tenuis represents an important source in constrained environments due to its capacity to tolerate abiotic stress conditions. L. tenuis has been correlated with Fusarium species which are key pathogens of important crops. However, some Fusarium species including the F. solani Species Complex, establish endophytic interactions with legumes. In this trend, Fusarium solani manages to infect the tissues of L. tenuis and L. japonicus. Preliminary metabolomics analysis revealed the involvement of phosphorylated compounds as metabolic traits of these interactions. However, the statistical approaches based either on one-way or multivariate analysis lack the systemic view denoted by the interaction between variables.We conducted metabolomics analysis based on gas chromatography-mass spectrometry (GC-MS/EI-TOF) on plant tissues under optimal conditions (Control), severe phosphate starvation (-P), F.solani presence (FUS+) and stress combination (FUS+P-). We profiled and analyzed the primary metabolism by conventional statistical approaches and took a step beyond by including a comparative correlation network analysis as a strategy to detect changes in interactions between central metabolites in response to our experimentally defined conditions.Considering the correlation network approach, the detection of patterns among metabolite interactions may change in response to the adaptation or acclimation of plant metabolism to environmental conditions. Such changes in interactions are typically not revealed by analyses of individual metabolites and they can exist even between metabolites that do not share the same metabolic pathway. By analyzing the network topology, we follow a pipeline to determine “hub” metabolites for eachbiological system. Therefore, these “hub” metabolites are consequently assumed to play crucial biological roles.Our results demonstrated that most hubs were present in the FUS+P- L. japonicus shoot network. The subsequent classification of compounds according to degree classes and betweenness centrality parameters determined a suit of hubs represented by biotic and abiotic stress-related metabolites. Among our results, sugars and sugar-related compounds exhibited relevant alterations in the metabolic response to the FUS+P- combination. Taken together, the determination of hubs by metabolite network analysis demonstrates the potential of this approach to find new perspectives in plant-fungal interactions research.