Comprehensive multivariate analysis of secondary metabolites in guayule: Insights into variability and breeding potential

Authors: GARCIA-CANO, PEDRO - University Of Castilla-La Mancha(UCLM); GARCIA-MARTINEZ, MERCEDES - University Of Castilla-La Mancha(UCLM); GONZALEZ, EMILIO - University Of Castilla-La Mancha(UCLM); ZALACAIN, AMAYA - University Of Castilla-La Mancha(UCLM); Ponciano, Grisel; Dong, Chen; McMahan, Colleen; CARMONA, MANUEL - University Of Castilla-La Mancha(UCLM); LATORRE, GUAYUENTE - University Of Castilla-La Mancha(UCLM)

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/24/2025
Publication Date: 10/30/2025
Citation: Garcia-Cano, P.J., Garcia-Martinez, M.M., Gonzalez, E.J., Zalacain, A., Ponciano, G.P., Dong, C., McMahan, C.M., Carmona, M., Latorre, G. 2025. Comprehensive multivariate analysis of secondary metabolites in guayule: Insights into variability and breeding potential. Industrial Crops and Products. 237. Article 122189. https://doi.org/10.1016/j.indcrop.2025.122189.
DOI: https://doi.org/10.1016/j.indcrop.2025.122189

Interpretive Summary: Guayule (Parthenium argentatum) is an alternative crop for production of natural rubber, a US Critical Agricultural Material, in the US Southwest. In addition to rubber, guayule produces a wide range of secondary metabolites, products such as terpene resins, essential oils, and phenolic compounds, with a variety of potential applications as biopesticides, biomedicines, cosmetics, and others. A big data meta-analysis was performed, comparing the quantity of >80 extractable compounds produced by 27 different field-grown guayule varieties over a period of five years in Spain. Advanced statistical tools such as Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), and Spearman correlation were used. These analyses revealed that while %resin and %rubber showed some differences, they were not sufficient to classify the different varieties. In contrast, the amount of sesquiterpenes compounds, particularly the %guayulins, were revealed to be strong biomarkers for genetic classification, correlating strongly with rubber and resin production. These results suggest that measuring % guayulins can help breeders maximize rubber yield and resin utilization.

Technical Abstract: Guayule (Parthenium argentatum A. Gray) is a promising alternative for the sustainable production of natural rubber. In addition to rubber, guayule produces a wide range of secondary metabolites, such as resin, essential oils, and phenolic compounds, with a variety of potential applications in fields as diverse as biopesticides, biomedicine, cosmetics, and other industries. However, the dynamics of these metabolites in the different accessions of guayule are not known in detail. Therefore, in the present study, a meta-analysis was performed with the data obtained by the research group over five years (82 metabolites in 27 accessions grown under standardized conditions) to evaluate their genetic and metabolic variability. Advanced statistical tools such as Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), and Spearman correlation were used. These analyses revealed that resin and rubber content alone are insufficient for accession differentiation. In contrast, sesquiterpenes, particularly guayulins, were revealed to be strong biomarkers for genetic classification, correlating strongly with rubber and resin biosynthetic pathways. In addition, guayulin A and guayulin C seem to have a high correlation with rubber. With respect to guayulins, this analysis also seems to indicate that their biosynthesis occurs in the leaves, starting with guayulin C and D, and that they are then translocated to the stem. These results suggest that a comprehensive metabolite profiling approach, focusing on specific compound groups, can improve guayule breeding strategies aimed at maximizing rubber yield and resin utilization.